Figure 6. Liriopsis pygmaea. (a, b) Habitus of early subadult female; (c) ventral habitus of adva... more Figure 6. Liriopsis pygmaea. (a, b) Habitus of early subadult female; (c) ventral habitus of advanced subadult female; (d, e) dorsal and ventral habitus of adult female; (f, g) adult female, details of anterior and posterior ends of the slit. Scale bars: 5 mm (a–e); 0.5 mm (f); 1 mm (g).
Figure 4. Liriopsis pygmaea. Cryptoniscus larva. (a) Dorsal habitus; (b) first antenna; (c) secon... more Figure 4. Liriopsis pygmaea. Cryptoniscus larva. (a) Dorsal habitus; (b) first antenna; (c) second antenna; (d) first pereopod, with detail of distal process of propodus. Scale bars: 0.5 mm (a); 0.1 mm (b–d).
Figure 1. Liriopsis pygmaea. SEM photographs of the epicaridium larva. (a) Ventral habitus; (b) v... more Figure 1. Liriopsis pygmaea. SEM photographs of the epicaridium larva. (a) Ventral habitus; (b) ventral view of abdomen; (c) detail of anal tube. All photographs belong to the same specimen.
Creemos necesario apelar a estrategias explicitas de ensenanza capaces de guiar la observacion a ... more Creemos necesario apelar a estrategias explicitas de ensenanza capaces de guiar la observacion a favor de una percepcion interpretativa del caracter simbolico de las imagenes histologicas, a partir de entornos mas familiares y sencillos para el observador, como pueden serlo las artes plasticas
The Cryptoniscidae are epicaridean isopod parasites or hyperparasites of other crustaceans. Lirio... more The Cryptoniscidae are epicaridean isopod parasites or hyperparasites of other crustaceans. Liriopsis Schultze in Mü ller, 1859, one of the genera included in this family, now contains two nominal species: L. pygmaea (Rathke, 1843) and L. monophthalma (Fraisse, 1878). Both of these species infest rhizocephalan cirripeds, which are in turn parasites of hermit crabs. Among the false king crabs, Paralomis granulosa (Jacquinot, 1847), captured commercially in the Beagle Channel in 1996-1998, we found 31 specimens of the rhizocephalan Briarosaccus callosus Boschma, 1930 infested by one or more specimens of L. pygmaea. Neither L. pygmaea nor L. monophthalma has been reported previously for the southern seas. Although unidentified isopod hyperparasites have been found on B. callosus infesting other lithodids from Crozet Islands, South Georgia Island and Canadian Atlantic waters, this is the first time that one of these hyperparasites has been identified as a member of the genus Liriopsis. Since the differences between L. pygmaea and L. monophthalma remain obscure, the epicaridium and cryptoniscus larvae and three females stages of L. pygmaea are herein described from the material collected in the Beagle Channel.
Crab size varied from 6.8 to 111.2 mm carapace length (CL). A few crabs parasitized by the rhizoc... more Crab size varied from 6.8 to 111.2 mm carapace length (CL). A few crabs parasitized by the rhizocephalan Briarosaccus callosus were found; prevalences of externae (the rhizocephalan reproductive body) and scars (the mark left on the host after the death of the parasite) were 0.28 and 0.16%, respectively. Of 85 externae examined, 55 were non-ovigerous and 30 ovigerous. The cryptoniscid isopod Liriopsis pygmaea infested 36.5% of the B. callosus examined. The most abundant stage was the cryptonicus larva, accounting for 208 of the 238 L. pygmaea recovered. Cryptonisci showed a highly aggregated distribution. A total of 92.7% of cryptonicsci were recovered inside empty externae, suggesting that the latter were attractive to cryptonisci. Early subadult females of L. pygmaea were rare; only 3 individuals occurred inside 1 ovigerous externa. Eight late subadult and 18 adult females were found on 3 and 7 non-ovigerous externae, respectively; in addition, 1 aberrant late subadult was found on 1 ovigerous externa. In the Beagle Channel, the population of P. granulosa harbours 3 different parasites: the bopyrid isopod Pseudione tuberculata, which reaches highest prevalence at 10 to 20 mm CL, the rhizocephalan B. callosus, with highest prevalence at 20 to 40 mm CL, and the cryptoniscid isopod L. pygmaea, which mainly infests rhizocephalan on crabs > 40 mm CL.
Figure 3. Liriopsis pygmaea. SEM photographs of the cryptoniscus larva. (a, b) Dorsal and ventral... more Figure 3. Liriopsis pygmaea. SEM photographs of the cryptoniscus larva. (a, b) Dorsal and ventral habitus; (c) ventral view of head, arrow shows the median plate partially covering the rostral teeth of the first antenna; (d) anterior part of first and second antennular articles, arrows show the first article with a rostral tooth completely exposed and the second article with a single median tooth; (e) ventral view showing the sixth (foreground) and seventh styliform pereopods; arrow indicates seventh coxal plate. Photographs (b) and (c) belong to the same specimen, the others to different specimens. Scale bars in mm.
Figure 6. Liriopsis pygmaea. (a, b) Habitus of early subadult female; (c) ventral habitus of adva... more Figure 6. Liriopsis pygmaea. (a, b) Habitus of early subadult female; (c) ventral habitus of advanced subadult female; (d, e) dorsal and ventral habitus of adult female; (f, g) adult female, details of anterior and posterior ends of the slit. Scale bars: 5 mm (a–e); 0.5 mm (f); 1 mm (g).
Figure 4. Liriopsis pygmaea. Cryptoniscus larva. (a) Dorsal habitus; (b) first antenna; (c) secon... more Figure 4. Liriopsis pygmaea. Cryptoniscus larva. (a) Dorsal habitus; (b) first antenna; (c) second antenna; (d) first pereopod, with detail of distal process of propodus. Scale bars: 0.5 mm (a); 0.1 mm (b–d).
Figure 1. Liriopsis pygmaea. SEM photographs of the epicaridium larva. (a) Ventral habitus; (b) v... more Figure 1. Liriopsis pygmaea. SEM photographs of the epicaridium larva. (a) Ventral habitus; (b) ventral view of abdomen; (c) detail of anal tube. All photographs belong to the same specimen.
Creemos necesario apelar a estrategias explicitas de ensenanza capaces de guiar la observacion a ... more Creemos necesario apelar a estrategias explicitas de ensenanza capaces de guiar la observacion a favor de una percepcion interpretativa del caracter simbolico de las imagenes histologicas, a partir de entornos mas familiares y sencillos para el observador, como pueden serlo las artes plasticas
The Cryptoniscidae are epicaridean isopod parasites or hyperparasites of other crustaceans. Lirio... more The Cryptoniscidae are epicaridean isopod parasites or hyperparasites of other crustaceans. Liriopsis Schultze in Mü ller, 1859, one of the genera included in this family, now contains two nominal species: L. pygmaea (Rathke, 1843) and L. monophthalma (Fraisse, 1878). Both of these species infest rhizocephalan cirripeds, which are in turn parasites of hermit crabs. Among the false king crabs, Paralomis granulosa (Jacquinot, 1847), captured commercially in the Beagle Channel in 1996-1998, we found 31 specimens of the rhizocephalan Briarosaccus callosus Boschma, 1930 infested by one or more specimens of L. pygmaea. Neither L. pygmaea nor L. monophthalma has been reported previously for the southern seas. Although unidentified isopod hyperparasites have been found on B. callosus infesting other lithodids from Crozet Islands, South Georgia Island and Canadian Atlantic waters, this is the first time that one of these hyperparasites has been identified as a member of the genus Liriopsis. Since the differences between L. pygmaea and L. monophthalma remain obscure, the epicaridium and cryptoniscus larvae and three females stages of L. pygmaea are herein described from the material collected in the Beagle Channel.
Crab size varied from 6.8 to 111.2 mm carapace length (CL). A few crabs parasitized by the rhizoc... more Crab size varied from 6.8 to 111.2 mm carapace length (CL). A few crabs parasitized by the rhizocephalan Briarosaccus callosus were found; prevalences of externae (the rhizocephalan reproductive body) and scars (the mark left on the host after the death of the parasite) were 0.28 and 0.16%, respectively. Of 85 externae examined, 55 were non-ovigerous and 30 ovigerous. The cryptoniscid isopod Liriopsis pygmaea infested 36.5% of the B. callosus examined. The most abundant stage was the cryptonicus larva, accounting for 208 of the 238 L. pygmaea recovered. Cryptonisci showed a highly aggregated distribution. A total of 92.7% of cryptonicsci were recovered inside empty externae, suggesting that the latter were attractive to cryptonisci. Early subadult females of L. pygmaea were rare; only 3 individuals occurred inside 1 ovigerous externa. Eight late subadult and 18 adult females were found on 3 and 7 non-ovigerous externae, respectively; in addition, 1 aberrant late subadult was found on 1 ovigerous externa. In the Beagle Channel, the population of P. granulosa harbours 3 different parasites: the bopyrid isopod Pseudione tuberculata, which reaches highest prevalence at 10 to 20 mm CL, the rhizocephalan B. callosus, with highest prevalence at 20 to 40 mm CL, and the cryptoniscid isopod L. pygmaea, which mainly infests rhizocephalan on crabs > 40 mm CL.
Figure 3. Liriopsis pygmaea. SEM photographs of the cryptoniscus larva. (a, b) Dorsal and ventral... more Figure 3. Liriopsis pygmaea. SEM photographs of the cryptoniscus larva. (a, b) Dorsal and ventral habitus; (c) ventral view of head, arrow shows the median plate partially covering the rostral teeth of the first antenna; (d) anterior part of first and second antennular articles, arrows show the first article with a rostral tooth completely exposed and the second article with a single median tooth; (e) ventral view showing the sixth (foreground) and seventh styliform pereopods; arrow indicates seventh coxal plate. Photographs (b) and (c) belong to the same specimen, the others to different specimens. Scale bars in mm.
Uploads
Papers by Laura Peresan