A note on the occurrence of praniza larvae of Gnathiidae (Crustacea, Isopoda) on fishes from Northeast of Pará, Brazil

Ectoparasites of the Critically Endangered green sawfish Pristis zijsron and sympatric elasmobranchs in Western Australia

This study reports the metazoan ectoparasite fauna of juvenile Critically Endangered green sawfish, Pristis zijsron, and sympatric elasmobranchs in Western Australia. Five parasite taxa were found on 76 screened P. zijsron: Caligus furcisetifer (Copepoda: Caligidae), Dermopristis pterophila (Monogenea: Microbothriidae), Branchellion plicobranchus and Stibarobdella macrothela (Hirudinea: Piscicolidae), and praniza larvae of an unidentified gnathiid isopod. Only C. furcisetifer and D. pterophila were common, exhibiting discrepant site-specificity, with C. furcisetifer occurring mostly on the head and rostrum, and D. pterophila around the pectoral and pelvic fins. Intensity of infection for C. furcisetifer and D. pterophila increased with host total length and was influenced by host sex, but in opposite directions; intensity of C. furcisetifer was greater on female P. zijsron, whereas intensity of D. pterophila was greater on males. In the Ashburton River, likelihood of infection for C. furcisetifer and D. pterophila on P. zijsron increased with time since substantial freshwater discharge events, suggesting decreased salinity impacts both taxa. In addition to P. zijsron, five other sympatric elasmobranch species were opportunistically screened for ectoparasites in the study area: the giant shovelnose ray, Glaucostegus typus, the eyebrow wedgefish, Rhynchobatus palpebratus, the nervous shark, Carcharhinus cautus, the lemon shark, Negaprion acutidens, and the graceful shark, Carcharhinus amblyrhynchoides. Caligus furcisetifer was found on R. palpebratus; no other parasites of P. zijsron were found on other sympatric elasmobranch species. Conversely, Perissopus dentatus (Copepoda: Pandaridae) was found on all three carcharhinids but not on batoid rays (P. zijsron, G. typus or R. palpebratus).

100 Million-year-old straight-jawed lacewing larvae with enormously inflated trunks represent the oldest cases of extreme physogastry in insects

Physogastry is a phenomenon occurring in Euarthropoda and describes an extreme inflation of (parts of) the trunk. It is best known from ticks, termite queens, or honey-pot ants, but can also be found in several other representatives of Euarthropoda. Physogastry has so far rarely been seen in the fossil record. We describe here an example of physogastry in two lacewing larvae (Neuroptera) enclosed in a single piece of Kachin amber (ca. 100 Ma old). We measured head and trunk ratios of different physogastric and non-physogastric representatives of Euarthropoda. Plotting these ratios shows that the new larvae, which display quite extremely inflated trunks, are very similar to ticks or honey-pot ants, but also to certain lacewing larvae of the group Berothidae (beaded lacewings). Outline analysis of head capsule and mouthparts (stylets) further suggests a position within Berothidae. Physogastry is presumed to be linked with living in confined spaces such as wood galleries or soil. Indeed, at least some larvae of Berothidae are known to live inside termite nests for part of their larval life phase, a habit the new larvae may also have had. The new record represents the oldest case of extreme physogastry in insects known to date.

New records of hosts for Excorallana longicornis and Nerocila acuminata (Crustacea: Isopoda) in brackish fish from the coast of the State of Amapá (Brazil), with an update on the geographic distribution of Nerocila acuminata

Fish are parasitized by several species of crustaceans, including Cymothoidae and Corallanidae. The aim of this study was to investigate the crustacean parasite fauna in Anableps anableps, Amphiarius rugispinis, Bagre bagre, Cathorops spixii, Cynoscion acoupa, Centropomus undecimalis, Macrodon ancylodon, Mugil curema, Megalops atlanticus, Pseudachenipterus nodosus, Plagioscion squamosissimus, Platystacus cotylephorus, Sciades passany, Sciades herzbergii, and Hypostomus ventrimaculata from the coast of the State of Amapá, eastern Amazon. In addition, an update on the geographic distribution of Nerocila acuminata in Brazilian Amazon is present. A total of 204 fish were examined and prevalence was 16.17%. A total of 185 Excorallana longicornis and Nerocila acuminata were collected and E. longicornis was the most frequent parasite species. The community of parasitic crustaceans in fish species from the coast of the State of Amapá consisted of two species of isopods, E. longicornis and N. acuminata, which are new records for nine host species here studied. Lastly, this is the first record of Nerocila acuminata for Brazil, besides the first report of E. longicornis for M. curema, C. acoupa, H. vetrimaculata, A. anableps, A. rugispinis, C. spixii and S. herzbergii; as well as N. acuminata for A. anableps, P. nodosus, A. rugispinis, C. spixii and M. atlanticus.

Short communication: first report of nematodes parasitizing the four-eyed-fish, Anableps anableps (Pisces, Cyprinodontiformes)

The genus Anableps is composed of species Anableps anableps, Anableps dowi, and Anableps microlepis. These fishes are tropical and usually live on the surface of brackish water, being popularly known as four-eyed-fishes due to the presence of prominent eyes and a pupil split horizontally. A. anableps and A. microlepis are considered as sister species that live in sympatry in South America. A. dowi, however, is restricted to the Pacific Ocean (Central America) and is considered the most primitive species of this genus. The aims of this study were to investigate the presence of endoparasites in A. anableps from the Parnaíba's Delta and characterize them morphologically. During the necropsy, larvae of Contracaecum sp. in the third larval stage (L3) were collected from the pancreas of A. anableps, but no endoparasites were observed in other organs. The worms had a cuticular tooth and excretory pore located at the anterior end, a thread like body, whitish color, and without distinction of sex. The length of the ventricular appendix of the larvae was much greater than in other studies. This is the first report of endoparasitism in A. anableps and the first report of nematodes in four-eyed-fishes.