Atlas of Invertebrate Reproduction and Development

Journal of Experimental Marine Biology and Ecology, 1992

2016

A case of simultaneous hermaphroditism in the Azorean endemic limpet Patella candei gomesii (Mollusca: Patellogastropoda), a gonochoristic species

The species Thamnocephalus venezuelensis is a native Venezuelan fairy shrimp that inhabits temporary ponds in semiarid zone in the north-western of the country. The complete larval development under laboratory conditions is described and illustrated; additionally the biometry of resting eggs (cysts) is characterized. Untreated and decapsulated cysts showed a mean diameter of 355 µm and 313 µm respectively. The first larval stage is a nauplius typical of the group that presented a mean length of 510 µm and 0.98 mg/egg of mean weight. These values have been the largest found in anostracan species until present. Larval development started with nauplii that gradually go through successive molts to reach the adult size. Females start producing eggs near twentieth day of development. Fairy shrimps have been considered for use as live food in larval fish rearing; therefore this information is of outstanding importance due to the potential value of T. venezuelensis for practical use in aquaculture or another practical purpose.

The effect of sublethal concentrations 0.00141% (LC,,), 0.0025 1% (LC,,) and 0.00336% (LC,) of a dispersible concentrated formulation of the insect growth regulator flufenoxuron (Cascade@), on larval growth and development, adult reproductive potential and egg hatchability of the red flour beetle, Tribolium castaneum, was investigated. When neonates were subjected to sublethal concentrations of flufenoxuron in artificial diet for 24 h, there were dose-dependent effects on larval weight, percent pupation and percent adult emergence, as well as time taken for adult emergence. A small proportion of larval-pupal as well as pupal-adult intermediates were observed at all concentrations. Adults emerging fiom the LCzo and LC3, concentrations laid mostly non-viable eggs, and the few larvae which emerged fiom viable eggs died at the first instar stage. At the LC, concentration, all the adults that emerged were deformed and subsequently died. Flufenoxuron exhibited transovarial ovicidal activity resulting in the production of non-viable eggs upon exposure of adults of different ages (2 days old, 3 days old and 4 days old) to treated diet. It was observed that in 2-day-old adults, fecundity decreased with an increased concentration. In the case of 3-day-old adults, there was no difference in fecundity with respect to the concentrations tested, although it was significantly less than the control. In the case of 4-day-old adults there was a drastic reduction in fecundity at LC, and the eggs laid were abnormal at all concentrations. Topical application of sublethal concentrations of flufenoxuron to adults of either sex reduced the fecundity in a dose-dependent manner. Furthermore, the fecundity was reduced drastically in pairs where both the sexes were treated as compared to the pairs where only one sex was treated. Eggs showed a decrease in hatching percentage with increasing concentrations of flufenoxuron mixed with diet to which the eggs were exposed.

1999

Publisher Summary This chapter presents an introduction to larval development, evolution and, ecology. The life history of many organisms includes a larval stage that is morphologically distinct from the adult's and/or that inhabits a different environment from the adult. The aquatic tadpole and the terrestrial frog are prime examples. Some species display indirect development; larvae must metamorphose to transform into, or be replaced by, adults. Larval evolution provides the key to unlocking metazoan evolution and diversification. Yet, because of larval adaptations (caenogenesis), only some larvae have provided useful information for reconstructing phylogenetic histories and evaluating evolutionary relationships. Embryos contain cells and developmental programs for both larval and adult structures. These may be completely separate, as in insects (in which adult cells are set aside in imaginal disks within the larval body), or they may be admixed, as in amphibians. Some larvae,...

Ethology, 2003

More than half a century of chemical communication research has served a key role in promoting awareness and expansion of knowledge in theoretical and applied problems in organismal biology. Tristram Wyatt's Pheromones and Animal Behaviour is an accessible textbook that offers advanced undergraduate and graduate students a data-based, integrative, and broadly comparative synthesis of this field. Crossing back and forth between invertebrate-vertebrate boundaries more freely than any other text in this area, Wyatt grounds behavioral, ecological, and biochemical observations of pheromonal communication in an evolutionary context. A broadly recognized caveat to workers in this field, derived from the primary literature and in this and other texts, is the willing acceptance and repetition of Ôjust soÕ evolutionary stories from researchers who contend to have identified absolute functions of pheromonal communication. Thirteen chapters fill the text. In several chapters, boxes and tables filled with straightforward and well situated summaries provide a ready reference location for students to check vocabulary terms and fundamental concepts. Careful production of the book is apparent, with very few typographic errors detected by this reviewer. Determining the optimum sequence for the chapters is a problem most textbook and course designers share. Wyatt's sequence moves from pheromone definitions and examples (Chapters 1 and 2) to behavioral and ecological discussions of pheromonal phenomena in six chapters (Chapters 3-8). Chapters 9 and 10 shift to chemoreception systems and transduction mechanisms and to biophysical problems faced by organisms attempting to locate pheromonal sources in the environment. Many instructors would likely place these problems after the first two introductory chapters, and then follow with the behavioral ecology issues of Chapters 3 through 8. Under such a rearrangement, Chapter 11, an interesting chapter on Ôpheromonal fraud,Õ logically follows the behavioral ecology chapters. Chapters 12 and 13, ÔApplicationsÕ and ÔHuman Pheromonal BiologyÕ, respectively, provide some attractive engagement, a strong theoretical and empirical foundation having been built in Chapters 1-11. An overview of the definitions and terminology used in chemical communication, and a synopsis of the diverse sources and functions of pheromones, are presented in Chapter 1. Regarding the latter, particularly compelling is a synthetic conceptual figure presenting as a spectrum, rather than as a dichotomy, the range of pheromonal functions between immediate behavioral ÔreleasersÕ and physiological ÔprimersÕ. There are 10 other figures in this chapter, two tables and two text boxes. Two of the figures include data. Several of the behavioral and chemical analyses used to identify pheromones are discussed in Chapter 2. Here arises the complexity that pheromonal effects are often based on responses to precise mixtures of component chemicals, observations that make this field so challenging to reduce to its essentials. Two of the six figures contain data, whereas three figures and a text box describe chemical analysis methodology. A strongly comparative approach to analyzing pheromonal communication in finding and choosing mates is used in Chapter 3. Though the attempt to develop an integrative synthesis on chemical communication's role in sexual selection and speciation is admirable, it is perhaps too uncritical, lacking prominent cautions necessary because of small sample sizes and impossibly confounded experimental designs, especially in field studies of vertebrate animals. Ten of the 15 figures feature empirical data, others show organisms and behavioral interactions, along with integrated summaries contained in one box and one table. Pheromonal communication related to aggregation and parasite-host interactions is presented in Chapter 4. The discussion includes sharing of resources, facilitation of mating, swamping of predators,

Frontiers in Physiology

KEYWORDS invertebrate animal models, invertebrate physiology, Drosophila melanogaster, RNAi-RNA interference, cephalopod, gene expression, fluorescent in situ hybridization (FISH), Bombyx mori Editorial on the Research Topic Methods and applications in invertebrate physiology Interest and research on invertebrate animal models has increased over the past decades and new methods and applications are being developed leading to fundamental physiological discoveries with applications ranging from biology to medicine. Invertebrate study systems thus have become cornerstones of biological and biomedical research, providing key insights into fields from genetics to behavioral ecology. Species being investigated and used as models range from terrestrial invertebrates such as insects and nematodes to freshwater and marine life including crustaceans, molluscs and many others. While the use of Drosophila for genetic studies was established in the early 20th century, it has since been used for many other applications including developmental biology, stem cell biology, endocrine function and metabolism, innate immunity, neurobiology, toxicology, etc. (Beckingham et al., 2005; Gilbert, 2008). Similarly, the nematode Caenorhabditis elegans has been utilized as a model system to investigate biological and physiological processes common to all animals (Strange, 2007). In recent years, there has been an increased use of other invertebrates to both understand the evolution of these organisms but also to throw light on developmental processes in higher animals (

Functional Ecology, 2016

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In Tempore Sueborum. El tiempo de los Suevos en la Gallaecia (411-585). El primer reino medieval de Occidente (Servicio de Publicaciones de la Diputación Provincial de Ourense), Ourense, 2017