Las descripciones larvarias de decápodos son esenciales para la comprensión de las estrategias de... more Las descripciones larvarias de decápodos son esenciales para la comprensión de las estrategias de la historia de vida, relaciones stock-reclutamiento y ecología planctónica. Para facilitar tales estudios, se entrega información concerniente a las descripciones publicadas de los estadíos tempranos de los decápodos que habitan aguas marinas y continentales chilenas. La publicación de los estudios morfológicos sobre larvas de decápodos comenzó en Chile en 1936, y el número de publicaciones mostró un claro aumento entre 1967 y 1973. Hasta la fecha, se ha descrito el desarrollo larvario completo de un 13,4% de los decápodos chilenos. El conocimiento concerniente a los estadíos larvarios de los camarones carídeos es extremadamente pobre, si se compara con la información disponible para las especies de anomuros (16%) y braquiuros (15%) reportados para Chile. La ausencia de descripciones larvarias para algunas especies comercialmente importantes no solamente dificulta la comprensión de la biología de estos crustáceos, sino también complica el desarrollo de estrategias de manejo adecuado.
Larvae of Portunus acuminatus (Stimpson, 1871) from one female, collected by trawling at a depth ... more Larvae of Portunus acuminatus (Stimpson, 1871) from one female, collected by trawling at a depth of 12 m in the Gulf of Nicoya, Pacific Costa Rica, Central America (090°48.899'N, 084°40.498'W) were hatched in the laboratory. The morphology of zoea I is described and illustrated for the first time and compared with known zoeae of other portunid species belonging to the subfamily Portuninae. We present a combination of three features which allows zoea I larvae of P. acuminatus to be distinguished from other described larvae of the genus. Descriptions are based on dissected larvae analysed by SEM and light microscopy. RESUMEN: MORFOLOGÍA DE LA PRIMERA ZOEA DE PORTUNUS ACUMINATUS (STIMPSON, 1871) OBTENIDA EN EL LABORATORIO. -Se describe el primer estadio larvario del cangrejo Portunus acuminatus.
A summary of the available information on stomatopod and decapod diversity of Isla del Coco and r... more A summary of the available information on stomatopod and decapod diversity of Isla del Coco and records of recently collected species during the CIMAR-MarViva expedition (January 2007) as well as the presence of yet unpublished specimens deposited in the Museo de Zoología, Universidad de Costa Rica, is reported. The material of the CIMAR-MarViva expedition comprised 23 species, including nine species new for the island. Revision of the collection of the Museo de Zoología, including two unpublished records, revealed the presence of additional 12 decapod species not previously reported for the island. Overall, a total of 135 species (6 stomatopods and 129 decapods) has been reported so far for the island, which harbors 29.5% of all decapod species known to occur along the Pacific mainland of Costa Rica, and 16.3% of all decapods reported for the Panamic Province. The most diverse families (including > 10 spp.) at Isla del Coco are Xanthidae (14 spp.), Majidae and Alpheidae (each 11 spp.), and Porcellanidae (10 spp.). There is a strong affinity of the stomatopod and decapod fauna of both Isla del Coco and Islas Galápagos. Rev. Biol. Trop. 56 (Suppl. 2): 79-97. Epub 2008 August 29.
This is the first record of a total of 22 species of penaeoid and caridean shrimps from Costa Ric... more This is the first record of a total of 22 species of penaeoid and caridean shrimps from Costa Rican waters: 16 were collected from the Caribbean coast, and six from the Pacific. Including the new records, a total of 142 shrimp species (Penaeoidea: 35; Caridea: 107) has been reported so far from Costa Rica waters.
Nest site selection for individual leatherback sea turtles, Dermochelys coriacea, is a matter of ... more Nest site selection for individual leatherback sea turtles, Dermochelys coriacea, is a matter of dispute. Some authors suggest that a female will tend to randomly scatter her nests to optimize clutch survival at a highly dynamic beach, while others suggest that some site fidelity exists. It is also possible that both strategies exist, depending on the characteristics of each nesting beach, with stable beaches leading to repeating nest site selections and unstable beaches leading to nest scattering. To determine the strategy of the Tortuguero population of D. coriacea, female site preference and repetition were determined by studying whether females repeat their nest zone choices between successive attempts and whether this leads to a correlation in hatching and emergence success of subsequent nests. Nesting data from 1997 to 2008 were used. Perpendicular to the coastline, open sand was preferred in general, regardless of initial choice. This shows a tendency to scatter nests and is consistent with the fact that all vertical zones had a high variability in hatching and emergence success. It is also consistent with nest success not being easily predictable, as shown by the lack of correlation in success of subsequent nesting attempts. Along the coastline, turtles showed a preference for the middle part of the studied section of beach, both at a population level and as a tendency to repeat their initial choice. Interestingly, this zone has the most artificial lights, which leads to slightly lower nest success (though not significantly so) and hatchling disorientation. This finding merits further study for a possibly maladaptive trait and shows the need for increased control of artificial nesting on this beach. Rev. Biol. Trop. 63 (2): 491-500. Epub 2015 June 01.
Growing concern about the quantity and diversity of by-catch species caught in the bottom trawlin... more Growing concern about the quantity and diversity of by-catch species caught in the bottom trawling nets of crustacean fisheries led us to compare the quantity of by-catch recorded in Chilean and Costa Rican deep-water shrimp fisheries by year, latitude, and bathymetry. We analyzed catches from 2143 trawl hauls between 2004 and 2009 from the fisheries of the northern nylon shrimp, Heterocarpus vicarius, and the kolibri shrimp, Solenocera agassizii, off Costa Rica and the Chilean nylon shrimp, Heterocarpus reedi, off Chile. A catch index was estimated to determine the quantity of by-catch retained for each kilogram of shrimp. The by-catch associated with the shrimp fisheries of Costa Rica and Chile was mainly fishes and crustaceans; by-catch species diversity was considerably higher in Costa Rica compared to that of Chile. In Chile, catches of H. reedi and by-catch were greater in the central and southern zone, whereas in Costa Rica, catches of shrimp (H. vicarius, S. agassizii) and by-catch were higher in the central zone. In terms of bathymetry, the largest catches of shrimp and by-catch came from the deep stratum (between 251 and 400 m) for both countries; the by-catch was noticeably larger in this stratum in Costa Rica. The catch index revealed that for every 1 kg of shrimp caught in Costa Rica, 5.7 kg of by-catch were caught; in Chile, this ratio was 1.1:1. However, the projected global by-catch was considerably higher for the fishery for H. reedi than for that of H. vicarius, which is related to the landed volumes of the target species in Costa Rica and Chile. The encouraging results in the H. reedi-fishery concerning technical measures to reduce by-catch and discards rates should be also considered for Central American deep-water shrimp fisheries.
Commercial fisheries are expanding their activities into deeper water. The life history features ... more Commercial fisheries are expanding their activities into deeper water. The life history features of these deep-water resources make them more vulnerable to exploitation than most shallow-water resources. Moreover, the apparent lack of solid information about the ecology of most deep-water species represents a major limitation for the development and implementation of management strategies. This scenario has caused great concern regarding the sustainability of these resources and the possible environmental impacts on the deep-sea ecosystem. In Latin America, commercial fisheries are going deep as well, and considering the above-mentioned concerns, we felt the need to compile the available information about the deep-water shrimp resources and the current status of their fisheries in Latin America. Focusing on Mexico, Central America, Peru, Chile and Brazil, this review describes the exploited species, and, whenever available, the fishing fleet, fishery statistics, and management strategies. A total of 17 species (10 spp. of Penaeoidea; 7 spp. of Caridea) are of commercial interest in Latin America, but deep-water shrimps are currently fished only in Costa Rica, Colombia and Chile. An implemented management plan exists in Chile and Colombia, while Brazil approved fishery regulations for the aristeid fishery, which were never implemented. Considering the lack of information about the biology of the deep-water shrimps, which hinders the development of adequate management strategies, we see the urgent need to improve the communication and collaboration between the different stakeholders in Latin American. We suggest the establishment of a searchable and constantly updated database, which may serve as a valuable source of information for researcher and decision makers. Finally, we propose the development of regional research plans aimed towards supporting measurements for a sustainable use of deep-water shrimps in Latin America.
Received 06-II-2006. Corrected 30-VI-2006. Accepted 30-VII-2006. Abstract: The alpheid shrimp Cor... more Received 06-II-2006. Corrected 30-VI-2006. Accepted 30-VII-2006. Abstract: The alpheid shrimp Coronalpheus natator Wicksten, 1999, originally described from the Galapagos Islands, is reported from waters of Isla Coiba National Park, Pacific coast of Panama. This is the first record of C. natator outside the type locality, and also the first record for near-continental waters of the eastern Pacific. The newly collected
The mangrove crab Aratus pisonii (H. Mile Edwards, 1837) was considered to have an amphi-American... more The mangrove crab Aratus pisonii (H. Mile Edwards, 1837) was considered to have an amphi-American distribution but a recent genetic study revealed that the Eastern Tropical Pacific populations represent a new species, A. pacificus (Thiercelin & Schubart, 2014). These sister species separated by the Central American Isthmus have developed under different environmental conditions that may influence their larval development. A comparison of morphological and morphometric features (length and width of cephalothorax and length of rostral and dorsal spine, antenna, antennule, telson, and furcae) of recently-hatched larvae of A. pacificus (Pacific coast) and A. pisonii (Caribbean coast) from Costa Rica revealed that the setation pattern of the antennules differed between the species and the analyzed morphometric features were larger in A. pisonii larvae. Difference in size may be a response to different environmental conditions, as the lower primary production in coastal Caribbean waters, ...
Typically, the most abundant group of shrimp larvae in the German Bight is formed by representati... more Typically, the most abundant group of shrimp larvae in the German Bight is formed by representatives of the family Crangonidae. Larvae of the remaining species have been largely ignored, and only scarce information concerning their ecology is available. Thus, the purpose of the present study was to determine the species composition, distribution and abundance of noncrangonid shrimp larvae in the German Bight in July 1990, after the mildest winter of the century. The material is based upon plankton samples collected at 77 stations, covering the entire German Bight. Eight species were identified, as well as larvae of Palaemonidae and Processa-juveniles. Processa nouveli holthuisi (53.0 %) and P. modica (31.3 %) were predominant in the collection. The distribution of the two species was clearly separated: the main concentration of P. nouveli holthuisi (peak concentration of 1.94 larvae per m 3) was confined to the northwest corner of the German Bight, while a majority of P. modica larvae (peak concentration of 0.54 larvae per m 3) occurred at the southwesterly stations. The spatial distribution of Caridion steveni and ]Zualus occultus around Helgoland indicates the presence of an adult population at the only rocky island in the study area. Other taxa, such as larvae of Palaemonidae and juvenile Pandalina brevirostris were collected exclusively in estuarine habitats. Based upon both the results of the present study and comparable data, we conclude that developmental stages of ten non-crangonid species, as well as representatives of Palaemonidae, can be expected to occur in the plankton of the German Bight. The extremely mild temperatures of the preceding winter may have been, in part, responsible for the relatively high densities of some taxa encountered during our plankton survey. We assume that warm winter temperatures favour the immigration, reproduction and survival of cold-sensitive species.
Intertidal to 10 m, protected calm water Coral rubble, hard substrates (often in shallow coves or... more Intertidal to 10 m, protected calm water Coral rubble, hard substrates (often in shallow coves or harbors)
Nest site selection for individual leatherback sea turtles, Dermochelys coriacea, is a matter of ... more Nest site selection for individual leatherback sea turtles, Dermochelys coriacea, is a matter of dispute. Some authors suggest that a female will tend to randomly scatter her nests to optimize clutch survival at a highly dynamic beach, while others suggest that some site fidelity exists. It is also possible that both strategies exist, depending on the characteristics of each nesting beach, with stable beaches leading to repeating nest site selections and unstable beaches leading to nest scattering. To determine the strategy of the Tortuguero population of D. coriacea, female site preference and repetition were determined by studying whether females repeat their nest zone choices between successive attempts and whether this leads to a correlation in hatching and emergence success of subsequent nests. Nesting data from 1997 to 2008 were used. Perpendicular to the coastline, open sand was preferred in general, regardless of initial choice. This shows a tendency to scatter nests and is consistent with the fact that all vertical zones had a high variability in hatching and emergence success. It is also consistent with nest success not being easily predictable, as shown by the lack of correlation in success of subsequent nesting attempts. Along the coastline, turtles showed a preference for the middle part of the studied section of beach, both at a population level and as a tendency to repeat their initial choice. Interestingly, this zone has the most artificial lights, which leads to slightly lower nest success (though not significantly so) and hatchling disorientation. This finding merits further study for a possibly maladaptive trait and shows the need for increased control of artificial nesting on this beach. Rev. Biol. Trop. 63 (2): 491-500. Epub 2015 June 01.
During the last decades, knowledge on biodiversity of freshwater decapods has increased considera... more During the last decades, knowledge on biodiversity of freshwater decapods has increased considerably; however, information about ecology of these crustaceans is scarce. Currently, the freshwater decapod fauna of Costa Rica is comprised by representatives of three families (Caridea: Palaemonidae and Atyidae; Brachyura: Pseudothelphusidae). The present study aims to describe the species diversity and distribution of freshwater crabs inhabiting the basin of the Rio Grande de Térraba, Pacific slope of Costa Rica, where the Instituto Costarricense de Electricidad (ICE) plans to implement one of the largest damming projects in the region. Samples were collected in 39 locations at an altitude ranging from 20 to 1,225 m. Sampling was carried out during several months in 2007, 2009 and 2010. We collected a total of 661 crabs, comprising eight species of Pseudothelphusidae of three genera, representing 53% of the 15 pseudothelphusid crab species currently recorded from Costa Rica. The most common species was Ptychophallus paraxanthusi followed by P. tristani. Freshwater crabs were more frequently encountered in the middle-low region of the basin (between 311 and 600 m) and less frequently in the medium-high basin (between 601 and 1,225 m). Ptychophallus paraxanthusi showed the widest distribution and was collected in altitudes ranging from 20 to 700 m. The Rio Grande de Térraba region can be considered as a relatively small, but highly diverse system. Therefore, any alteration of the basin of Rio Grande de Térraba, and especially the possible construction of a hydroelectric power plant, needs to be carefully analyzed to mitigate the damaging effects of this project on the freshwater crabs. More ecological information about freshwater crabs from Costa Rica and the Central American region are needed to reach a first reasonable overview on the ecological role of these decapods in freshwater systems.
Sexuality and Early Development in Aquatic Organisms, 2014
Solenocera agassizii is commercially exploited along the Costa Rican Pacific coast and represents... more Solenocera agassizii is commercially exploited along the Costa Rican Pacific coast and represents around 30% of the country's total shrimp catch. Despite its economic importance, information on its biology is scarce. Here we describe its secondary sexual characters and spermatophores. The open thelycum is located between Sternites XIII and XIV. A pair of parallel setose projections (Sternite XIV) is distally curved in larger females (< 30 mm carapace length); a disk-shaped projection (Sternite XIII) emerges from Pereopod IV and projects towards Sternite XIV, and a triangular emargination is present (Sternite XIII). The semi-open petasma with cincinnulli connecting the pleopods in mature males has sclerotized dorsolateral (DL), ventrolateral (VL) and ventromedian (VM) lobules. The VM tooth-like projections fit the VL tooth-like projections. The DL and VL lobules end in a leaf-like, less sclerotized projection and are separated by a gap. The VL lobule has a patch of spinules and a highly sclerotized costa. An elongated appendix masculina (AM) with concave margin forms a distal subtriangular lobe and has a DL margin with an aggregation of setae. The AM fits inside the appendix interna (AI) and is shorter and narrower than the AM. The spermatophore has superior (wing) and inferior (germinate body) sections. The GB ends in a triangular hook-like structure. The thelycum resembles that of S. geijskesi, whereas the petasma, AM and AI are similar to those of Atlantic solenocerids. The complex spermatophore resembles that of other penaeoid shrimp. According to evolutionary trends, S. agassizii can be considered as a less derived species within the Dendrobranchiata.
Eggs of the decapod shrimps, Chorismus antarcticus, Nematocarcinus lanceopes and Notocrangon anta... more Eggs of the decapod shrimps, Chorismus antarcticus, Nematocarcinus lanceopes and Notocrangon antarcticus were taken to analyse their morphometric, lipid and fatty acid composition. Almost all females carried undifferentiated eggs (stage I). The average number of recently extruded eggs was lowest in C. antarcticus with 163 eggs, and highest in Nematocarcinus lanceopes with 1,220 eggs, while Notocrangon antarcticus produced on average 350 eggs. The lipid content (% of dry mass) of the eggs was 18.8% for C. antarcticus, 14.3% for Notocrangon antarcticus and 18.1% for Nematocarcinus lanceopes. Dominant lipid classes in eggs of all species were phospholipids and triacylglycerols. The storage lipid, triacylglycerol, was slightly elevated in the eggs of Nematocarcinus lanceopes (mean of 52.7%) compared to the other two species. The fatty acid compositions of the decapod eggs were similar in the three species. Dominant fatty acids were 20:5(n-3), 18:1(n-9), 16:1(n-7), 16:0 and 18:1(n-7), comprising 75.8-78.4% of total fatty acids. Among the species, the eggs of C. antarcticus had the highest proportions of polyunsaturated fatty acids (39.6%), dominated by 20:5(n-3), and the lowest percentage of monounsaturates (41.8%). The eggs of Nematocarcinus lanceopes and Notocrangon antarcticus contained almost the same proportion of polyunsaturated fatty acids (28.0% and 28.4%, respectively), whereas Nematocarcinus lanceopes had the highest amount of monounsaturates due to the dominance of 18:1(n-9). Based on our findings, we assume that eggs produced by polar decapod crustaceans do not contain substantially more lipids than related species from temperate or tropical regions. However, additional studies are necessary to substantiate any general conclusion about the relationship of egg lipid content and composition with climatic zones.
The taxonomy and geographic distribution of the freshwater crabs of the family Pseudothelphusidae... more The taxonomy and geographic distribution of the freshwater crabs of the family Pseudothelphusidae Ortmann, 1893, of Costa Rica, Central America, particularly of the genus Ptychophallus Smalley, 1964, are revised. Historical materials deposited in major collections of several institutions were examined, as well as valuable collections in the Zoological Museum of the University of Costa Rica that include abundant specimens obtained recently (2007-2010) in the southern region of the country. The pseudothelphusids of Costa Rica consists of 15 currently valid species belonging to Achlidon Smalley, 1964 (two species), Allacanthos Smalley, 1964 (two species), Potamocarcinus H. Milne Edwards, 1853 (three species), and Ptychophallus (eight species). Two species seem to be restricted to the Atlantic drainage, while seven are known only from the Pacific drainage; six species occur in both drainages. Ptychophallus comprises 13 valid species; four new synonymies are proposed: P. osaensis Rodrígu...
The closure of the Isthmus of Panama (about 3.1 million years ago) separated previously continuou... more The closure of the Isthmus of Panama (about 3.1 million years ago) separated previously continuous populations and created two groups of extant species, which live now in the Pacific and Atlantic drainage systems. This relatively recent event was a trigger to diversification of various species in the Neotropics, nonetheless there are exemplars that do not show sufficient morphologic variability to separate them by traditional morphological tools. About 60 years ago, some freshwater decapod species with high morphological similarity were separate by previous researchers, based on geographical distribution, in Pacific and Atlantic and considered as "sister species". However, the complete isolation of these prawns by this geographical barrier is questionable, and it has generated doubts about the status of the following transisthmian pairs of sibling species: Macrobrachium occidentale × M. heterochirus, M. americanum × M. carcinus, M. digueti × M. olfersii, M. hancocki × M. crenulatum, M. tenellum × M. acanthurus and M. panamense × M. amazonicum. Here we evaluated the relation among these pairs of sibling species in a molecular phylogenetic context. We generated 95 new sequences: 26 sequences of 16S rDNA, 25 of COI mtDNA and 44 of 18S nDNA. In total, 181 sequences were analyzed by maximum likelihood phylogenetic method, including 12 Macrobrachium transisthmian species, as well A peer-reviewed open-access journal Leonardo G. Pileggi et al. / ZooKeys 457: 109-131 (2014) 110 as seven other American Macrobrachium species, and two other palaemonids. Our analysis corroborated the morphological proximity of the sibling species. Despite the high degree of morphological similarities and considerable genetic diversification encountered among the transisthmian sister species, our data support the conclusion that all species included in sibling groups studied herein are valid taxonomic entities, but not all pairs of siblings form natural groups.
Las descripciones larvarias de decápodos son esenciales para la comprensión de las estrategias de... more Las descripciones larvarias de decápodos son esenciales para la comprensión de las estrategias de la historia de vida, relaciones stock-reclutamiento y ecología planctónica. Para facilitar tales estudios, se entrega información concerniente a las descripciones publicadas de los estadíos tempranos de los decápodos que habitan aguas marinas y continentales chilenas. La publicación de los estudios morfológicos sobre larvas de decápodos comenzó en Chile en 1936, y el número de publicaciones mostró un claro aumento entre 1967 y 1973. Hasta la fecha, se ha descrito el desarrollo larvario completo de un 13,4% de los decápodos chilenos. El conocimiento concerniente a los estadíos larvarios de los camarones carídeos es extremadamente pobre, si se compara con la información disponible para las especies de anomuros (16%) y braquiuros (15%) reportados para Chile. La ausencia de descripciones larvarias para algunas especies comercialmente importantes no solamente dificulta la comprensión de la biología de estos crustáceos, sino también complica el desarrollo de estrategias de manejo adecuado.
Larvae of Portunus acuminatus (Stimpson, 1871) from one female, collected by trawling at a depth ... more Larvae of Portunus acuminatus (Stimpson, 1871) from one female, collected by trawling at a depth of 12 m in the Gulf of Nicoya, Pacific Costa Rica, Central America (090°48.899'N, 084°40.498'W) were hatched in the laboratory. The morphology of zoea I is described and illustrated for the first time and compared with known zoeae of other portunid species belonging to the subfamily Portuninae. We present a combination of three features which allows zoea I larvae of P. acuminatus to be distinguished from other described larvae of the genus. Descriptions are based on dissected larvae analysed by SEM and light microscopy. RESUMEN: MORFOLOGÍA DE LA PRIMERA ZOEA DE PORTUNUS ACUMINATUS (STIMPSON, 1871) OBTENIDA EN EL LABORATORIO. -Se describe el primer estadio larvario del cangrejo Portunus acuminatus.
A summary of the available information on stomatopod and decapod diversity of Isla del Coco and r... more A summary of the available information on stomatopod and decapod diversity of Isla del Coco and records of recently collected species during the CIMAR-MarViva expedition (January 2007) as well as the presence of yet unpublished specimens deposited in the Museo de Zoología, Universidad de Costa Rica, is reported. The material of the CIMAR-MarViva expedition comprised 23 species, including nine species new for the island. Revision of the collection of the Museo de Zoología, including two unpublished records, revealed the presence of additional 12 decapod species not previously reported for the island. Overall, a total of 135 species (6 stomatopods and 129 decapods) has been reported so far for the island, which harbors 29.5% of all decapod species known to occur along the Pacific mainland of Costa Rica, and 16.3% of all decapods reported for the Panamic Province. The most diverse families (including > 10 spp.) at Isla del Coco are Xanthidae (14 spp.), Majidae and Alpheidae (each 11 spp.), and Porcellanidae (10 spp.). There is a strong affinity of the stomatopod and decapod fauna of both Isla del Coco and Islas Galápagos. Rev. Biol. Trop. 56 (Suppl. 2): 79-97. Epub 2008 August 29.
This is the first record of a total of 22 species of penaeoid and caridean shrimps from Costa Ric... more This is the first record of a total of 22 species of penaeoid and caridean shrimps from Costa Rican waters: 16 were collected from the Caribbean coast, and six from the Pacific. Including the new records, a total of 142 shrimp species (Penaeoidea: 35; Caridea: 107) has been reported so far from Costa Rica waters.
Nest site selection for individual leatherback sea turtles, Dermochelys coriacea, is a matter of ... more Nest site selection for individual leatherback sea turtles, Dermochelys coriacea, is a matter of dispute. Some authors suggest that a female will tend to randomly scatter her nests to optimize clutch survival at a highly dynamic beach, while others suggest that some site fidelity exists. It is also possible that both strategies exist, depending on the characteristics of each nesting beach, with stable beaches leading to repeating nest site selections and unstable beaches leading to nest scattering. To determine the strategy of the Tortuguero population of D. coriacea, female site preference and repetition were determined by studying whether females repeat their nest zone choices between successive attempts and whether this leads to a correlation in hatching and emergence success of subsequent nests. Nesting data from 1997 to 2008 were used. Perpendicular to the coastline, open sand was preferred in general, regardless of initial choice. This shows a tendency to scatter nests and is consistent with the fact that all vertical zones had a high variability in hatching and emergence success. It is also consistent with nest success not being easily predictable, as shown by the lack of correlation in success of subsequent nesting attempts. Along the coastline, turtles showed a preference for the middle part of the studied section of beach, both at a population level and as a tendency to repeat their initial choice. Interestingly, this zone has the most artificial lights, which leads to slightly lower nest success (though not significantly so) and hatchling disorientation. This finding merits further study for a possibly maladaptive trait and shows the need for increased control of artificial nesting on this beach. Rev. Biol. Trop. 63 (2): 491-500. Epub 2015 June 01.
Growing concern about the quantity and diversity of by-catch species caught in the bottom trawlin... more Growing concern about the quantity and diversity of by-catch species caught in the bottom trawling nets of crustacean fisheries led us to compare the quantity of by-catch recorded in Chilean and Costa Rican deep-water shrimp fisheries by year, latitude, and bathymetry. We analyzed catches from 2143 trawl hauls between 2004 and 2009 from the fisheries of the northern nylon shrimp, Heterocarpus vicarius, and the kolibri shrimp, Solenocera agassizii, off Costa Rica and the Chilean nylon shrimp, Heterocarpus reedi, off Chile. A catch index was estimated to determine the quantity of by-catch retained for each kilogram of shrimp. The by-catch associated with the shrimp fisheries of Costa Rica and Chile was mainly fishes and crustaceans; by-catch species diversity was considerably higher in Costa Rica compared to that of Chile. In Chile, catches of H. reedi and by-catch were greater in the central and southern zone, whereas in Costa Rica, catches of shrimp (H. vicarius, S. agassizii) and by-catch were higher in the central zone. In terms of bathymetry, the largest catches of shrimp and by-catch came from the deep stratum (between 251 and 400 m) for both countries; the by-catch was noticeably larger in this stratum in Costa Rica. The catch index revealed that for every 1 kg of shrimp caught in Costa Rica, 5.7 kg of by-catch were caught; in Chile, this ratio was 1.1:1. However, the projected global by-catch was considerably higher for the fishery for H. reedi than for that of H. vicarius, which is related to the landed volumes of the target species in Costa Rica and Chile. The encouraging results in the H. reedi-fishery concerning technical measures to reduce by-catch and discards rates should be also considered for Central American deep-water shrimp fisheries.
Commercial fisheries are expanding their activities into deeper water. The life history features ... more Commercial fisheries are expanding their activities into deeper water. The life history features of these deep-water resources make them more vulnerable to exploitation than most shallow-water resources. Moreover, the apparent lack of solid information about the ecology of most deep-water species represents a major limitation for the development and implementation of management strategies. This scenario has caused great concern regarding the sustainability of these resources and the possible environmental impacts on the deep-sea ecosystem. In Latin America, commercial fisheries are going deep as well, and considering the above-mentioned concerns, we felt the need to compile the available information about the deep-water shrimp resources and the current status of their fisheries in Latin America. Focusing on Mexico, Central America, Peru, Chile and Brazil, this review describes the exploited species, and, whenever available, the fishing fleet, fishery statistics, and management strategies. A total of 17 species (10 spp. of Penaeoidea; 7 spp. of Caridea) are of commercial interest in Latin America, but deep-water shrimps are currently fished only in Costa Rica, Colombia and Chile. An implemented management plan exists in Chile and Colombia, while Brazil approved fishery regulations for the aristeid fishery, which were never implemented. Considering the lack of information about the biology of the deep-water shrimps, which hinders the development of adequate management strategies, we see the urgent need to improve the communication and collaboration between the different stakeholders in Latin American. We suggest the establishment of a searchable and constantly updated database, which may serve as a valuable source of information for researcher and decision makers. Finally, we propose the development of regional research plans aimed towards supporting measurements for a sustainable use of deep-water shrimps in Latin America.
Received 06-II-2006. Corrected 30-VI-2006. Accepted 30-VII-2006. Abstract: The alpheid shrimp Cor... more Received 06-II-2006. Corrected 30-VI-2006. Accepted 30-VII-2006. Abstract: The alpheid shrimp Coronalpheus natator Wicksten, 1999, originally described from the Galapagos Islands, is reported from waters of Isla Coiba National Park, Pacific coast of Panama. This is the first record of C. natator outside the type locality, and also the first record for near-continental waters of the eastern Pacific. The newly collected
The mangrove crab Aratus pisonii (H. Mile Edwards, 1837) was considered to have an amphi-American... more The mangrove crab Aratus pisonii (H. Mile Edwards, 1837) was considered to have an amphi-American distribution but a recent genetic study revealed that the Eastern Tropical Pacific populations represent a new species, A. pacificus (Thiercelin & Schubart, 2014). These sister species separated by the Central American Isthmus have developed under different environmental conditions that may influence their larval development. A comparison of morphological and morphometric features (length and width of cephalothorax and length of rostral and dorsal spine, antenna, antennule, telson, and furcae) of recently-hatched larvae of A. pacificus (Pacific coast) and A. pisonii (Caribbean coast) from Costa Rica revealed that the setation pattern of the antennules differed between the species and the analyzed morphometric features were larger in A. pisonii larvae. Difference in size may be a response to different environmental conditions, as the lower primary production in coastal Caribbean waters, ...
Typically, the most abundant group of shrimp larvae in the German Bight is formed by representati... more Typically, the most abundant group of shrimp larvae in the German Bight is formed by representatives of the family Crangonidae. Larvae of the remaining species have been largely ignored, and only scarce information concerning their ecology is available. Thus, the purpose of the present study was to determine the species composition, distribution and abundance of noncrangonid shrimp larvae in the German Bight in July 1990, after the mildest winter of the century. The material is based upon plankton samples collected at 77 stations, covering the entire German Bight. Eight species were identified, as well as larvae of Palaemonidae and Processa-juveniles. Processa nouveli holthuisi (53.0 %) and P. modica (31.3 %) were predominant in the collection. The distribution of the two species was clearly separated: the main concentration of P. nouveli holthuisi (peak concentration of 1.94 larvae per m 3) was confined to the northwest corner of the German Bight, while a majority of P. modica larvae (peak concentration of 0.54 larvae per m 3) occurred at the southwesterly stations. The spatial distribution of Caridion steveni and ]Zualus occultus around Helgoland indicates the presence of an adult population at the only rocky island in the study area. Other taxa, such as larvae of Palaemonidae and juvenile Pandalina brevirostris were collected exclusively in estuarine habitats. Based upon both the results of the present study and comparable data, we conclude that developmental stages of ten non-crangonid species, as well as representatives of Palaemonidae, can be expected to occur in the plankton of the German Bight. The extremely mild temperatures of the preceding winter may have been, in part, responsible for the relatively high densities of some taxa encountered during our plankton survey. We assume that warm winter temperatures favour the immigration, reproduction and survival of cold-sensitive species.
Intertidal to 10 m, protected calm water Coral rubble, hard substrates (often in shallow coves or... more Intertidal to 10 m, protected calm water Coral rubble, hard substrates (often in shallow coves or harbors)
Nest site selection for individual leatherback sea turtles, Dermochelys coriacea, is a matter of ... more Nest site selection for individual leatherback sea turtles, Dermochelys coriacea, is a matter of dispute. Some authors suggest that a female will tend to randomly scatter her nests to optimize clutch survival at a highly dynamic beach, while others suggest that some site fidelity exists. It is also possible that both strategies exist, depending on the characteristics of each nesting beach, with stable beaches leading to repeating nest site selections and unstable beaches leading to nest scattering. To determine the strategy of the Tortuguero population of D. coriacea, female site preference and repetition were determined by studying whether females repeat their nest zone choices between successive attempts and whether this leads to a correlation in hatching and emergence success of subsequent nests. Nesting data from 1997 to 2008 were used. Perpendicular to the coastline, open sand was preferred in general, regardless of initial choice. This shows a tendency to scatter nests and is consistent with the fact that all vertical zones had a high variability in hatching and emergence success. It is also consistent with nest success not being easily predictable, as shown by the lack of correlation in success of subsequent nesting attempts. Along the coastline, turtles showed a preference for the middle part of the studied section of beach, both at a population level and as a tendency to repeat their initial choice. Interestingly, this zone has the most artificial lights, which leads to slightly lower nest success (though not significantly so) and hatchling disorientation. This finding merits further study for a possibly maladaptive trait and shows the need for increased control of artificial nesting on this beach. Rev. Biol. Trop. 63 (2): 491-500. Epub 2015 June 01.
During the last decades, knowledge on biodiversity of freshwater decapods has increased considera... more During the last decades, knowledge on biodiversity of freshwater decapods has increased considerably; however, information about ecology of these crustaceans is scarce. Currently, the freshwater decapod fauna of Costa Rica is comprised by representatives of three families (Caridea: Palaemonidae and Atyidae; Brachyura: Pseudothelphusidae). The present study aims to describe the species diversity and distribution of freshwater crabs inhabiting the basin of the Rio Grande de Térraba, Pacific slope of Costa Rica, where the Instituto Costarricense de Electricidad (ICE) plans to implement one of the largest damming projects in the region. Samples were collected in 39 locations at an altitude ranging from 20 to 1,225 m. Sampling was carried out during several months in 2007, 2009 and 2010. We collected a total of 661 crabs, comprising eight species of Pseudothelphusidae of three genera, representing 53% of the 15 pseudothelphusid crab species currently recorded from Costa Rica. The most common species was Ptychophallus paraxanthusi followed by P. tristani. Freshwater crabs were more frequently encountered in the middle-low region of the basin (between 311 and 600 m) and less frequently in the medium-high basin (between 601 and 1,225 m). Ptychophallus paraxanthusi showed the widest distribution and was collected in altitudes ranging from 20 to 700 m. The Rio Grande de Térraba region can be considered as a relatively small, but highly diverse system. Therefore, any alteration of the basin of Rio Grande de Térraba, and especially the possible construction of a hydroelectric power plant, needs to be carefully analyzed to mitigate the damaging effects of this project on the freshwater crabs. More ecological information about freshwater crabs from Costa Rica and the Central American region are needed to reach a first reasonable overview on the ecological role of these decapods in freshwater systems.
Sexuality and Early Development in Aquatic Organisms, 2014
Solenocera agassizii is commercially exploited along the Costa Rican Pacific coast and represents... more Solenocera agassizii is commercially exploited along the Costa Rican Pacific coast and represents around 30% of the country's total shrimp catch. Despite its economic importance, information on its biology is scarce. Here we describe its secondary sexual characters and spermatophores. The open thelycum is located between Sternites XIII and XIV. A pair of parallel setose projections (Sternite XIV) is distally curved in larger females (< 30 mm carapace length); a disk-shaped projection (Sternite XIII) emerges from Pereopod IV and projects towards Sternite XIV, and a triangular emargination is present (Sternite XIII). The semi-open petasma with cincinnulli connecting the pleopods in mature males has sclerotized dorsolateral (DL), ventrolateral (VL) and ventromedian (VM) lobules. The VM tooth-like projections fit the VL tooth-like projections. The DL and VL lobules end in a leaf-like, less sclerotized projection and are separated by a gap. The VL lobule has a patch of spinules and a highly sclerotized costa. An elongated appendix masculina (AM) with concave margin forms a distal subtriangular lobe and has a DL margin with an aggregation of setae. The AM fits inside the appendix interna (AI) and is shorter and narrower than the AM. The spermatophore has superior (wing) and inferior (germinate body) sections. The GB ends in a triangular hook-like structure. The thelycum resembles that of S. geijskesi, whereas the petasma, AM and AI are similar to those of Atlantic solenocerids. The complex spermatophore resembles that of other penaeoid shrimp. According to evolutionary trends, S. agassizii can be considered as a less derived species within the Dendrobranchiata.
Eggs of the decapod shrimps, Chorismus antarcticus, Nematocarcinus lanceopes and Notocrangon anta... more Eggs of the decapod shrimps, Chorismus antarcticus, Nematocarcinus lanceopes and Notocrangon antarcticus were taken to analyse their morphometric, lipid and fatty acid composition. Almost all females carried undifferentiated eggs (stage I). The average number of recently extruded eggs was lowest in C. antarcticus with 163 eggs, and highest in Nematocarcinus lanceopes with 1,220 eggs, while Notocrangon antarcticus produced on average 350 eggs. The lipid content (% of dry mass) of the eggs was 18.8% for C. antarcticus, 14.3% for Notocrangon antarcticus and 18.1% for Nematocarcinus lanceopes. Dominant lipid classes in eggs of all species were phospholipids and triacylglycerols. The storage lipid, triacylglycerol, was slightly elevated in the eggs of Nematocarcinus lanceopes (mean of 52.7%) compared to the other two species. The fatty acid compositions of the decapod eggs were similar in the three species. Dominant fatty acids were 20:5(n-3), 18:1(n-9), 16:1(n-7), 16:0 and 18:1(n-7), comprising 75.8-78.4% of total fatty acids. Among the species, the eggs of C. antarcticus had the highest proportions of polyunsaturated fatty acids (39.6%), dominated by 20:5(n-3), and the lowest percentage of monounsaturates (41.8%). The eggs of Nematocarcinus lanceopes and Notocrangon antarcticus contained almost the same proportion of polyunsaturated fatty acids (28.0% and 28.4%, respectively), whereas Nematocarcinus lanceopes had the highest amount of monounsaturates due to the dominance of 18:1(n-9). Based on our findings, we assume that eggs produced by polar decapod crustaceans do not contain substantially more lipids than related species from temperate or tropical regions. However, additional studies are necessary to substantiate any general conclusion about the relationship of egg lipid content and composition with climatic zones.
The taxonomy and geographic distribution of the freshwater crabs of the family Pseudothelphusidae... more The taxonomy and geographic distribution of the freshwater crabs of the family Pseudothelphusidae Ortmann, 1893, of Costa Rica, Central America, particularly of the genus Ptychophallus Smalley, 1964, are revised. Historical materials deposited in major collections of several institutions were examined, as well as valuable collections in the Zoological Museum of the University of Costa Rica that include abundant specimens obtained recently (2007-2010) in the southern region of the country. The pseudothelphusids of Costa Rica consists of 15 currently valid species belonging to Achlidon Smalley, 1964 (two species), Allacanthos Smalley, 1964 (two species), Potamocarcinus H. Milne Edwards, 1853 (three species), and Ptychophallus (eight species). Two species seem to be restricted to the Atlantic drainage, while seven are known only from the Pacific drainage; six species occur in both drainages. Ptychophallus comprises 13 valid species; four new synonymies are proposed: P. osaensis Rodrígu...
The closure of the Isthmus of Panama (about 3.1 million years ago) separated previously continuou... more The closure of the Isthmus of Panama (about 3.1 million years ago) separated previously continuous populations and created two groups of extant species, which live now in the Pacific and Atlantic drainage systems. This relatively recent event was a trigger to diversification of various species in the Neotropics, nonetheless there are exemplars that do not show sufficient morphologic variability to separate them by traditional morphological tools. About 60 years ago, some freshwater decapod species with high morphological similarity were separate by previous researchers, based on geographical distribution, in Pacific and Atlantic and considered as "sister species". However, the complete isolation of these prawns by this geographical barrier is questionable, and it has generated doubts about the status of the following transisthmian pairs of sibling species: Macrobrachium occidentale × M. heterochirus, M. americanum × M. carcinus, M. digueti × M. olfersii, M. hancocki × M. crenulatum, M. tenellum × M. acanthurus and M. panamense × M. amazonicum. Here we evaluated the relation among these pairs of sibling species in a molecular phylogenetic context. We generated 95 new sequences: 26 sequences of 16S rDNA, 25 of COI mtDNA and 44 of 18S nDNA. In total, 181 sequences were analyzed by maximum likelihood phylogenetic method, including 12 Macrobrachium transisthmian species, as well A peer-reviewed open-access journal Leonardo G. Pileggi et al. / ZooKeys 457: 109-131 (2014) 110 as seven other American Macrobrachium species, and two other palaemonids. Our analysis corroborated the morphological proximity of the sibling species. Despite the high degree of morphological similarities and considerable genetic diversification encountered among the transisthmian sister species, our data support the conclusion that all species included in sibling groups studied herein are valid taxonomic entities, but not all pairs of siblings form natural groups.
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