Redescription of Triceracolax pagri Izawa, 2021 (Copepoda, Cyclopoida, Bomolochidae), with descriptions of copepodids IV and III of the species

Triceracolax pagri Izawa, 2021 is redescribed on the basis of specimens of both sexes recovered from the bucco-branchial cavity of the original host, Pagrus major (Temminck & Schlegel, 1843). Both sexes of copepodid IV and the male copepodid III, collected together with the adults, are described for the first time, and sexually dimorphic features in late copepodid stages are discussed.

New Records of Fish Parasitic Isopods (Crustacea: Isopoda) from the Gulf of Thailand

From a total of 4140 marine fishes examined, eight species of parasitic isopods were reported from marine fishes in the Gulf of Thailand. These isopods were identified in two families, Corallanidae (Argathona macronema and Argathona rhinoceros) and Cymothoidae (Cymothoa eremita, Cymothoa elegans, Smenispa irregularis, Nerocila sundaica, Norileca indica and Norileca triangulata). Most of these parasitic isopods were found in the buccal cavity of their fish hosts with one host recorded as follows: C. eremita was found from Nemipterus hexodon, C. elegans was found from Scatophagus argus, N. sundaica was found from Saurida tumbil. The majority of the isopod specimens recorded in this study was S. irregularis, which was found in the buccal cavities of five host fish, Pampus argentius, Alepes melanoptera, Caranx hippos, Parastromateus niger and Terapon jarbua, with a prevalence of 11.67%, 10.43%, 9.78%, 6.10% and 4.21%, respectively. Argathona rhinoceros was found in the nasal cavity and branchial cavity of Epinephelus coioides, whereas A. macronema and N. triangulata were found on the skin of Epinephelus coioides and Seriolina nigrofasciata, respectively. The highest species diversity was found in E. coioides, which harbored two species of parasitic isopods, A. macronema and A. rhinoceros. Cymothoa eremita, C. elegans, S. irregularis and N. triangulata were recorded for the first time in the Gulf of Thailand. The reported discovery of C. eremita, S. irregularis, N. sundaica and N. triangulata in their fish hosts were new recorded hosts. Moreover, A. macronema and N. triangulata were found for the first time in the central Indo-Pacific region.

The discovery of Lepeophtheirus acutus Heegaard, 1943 (Copepoda: Caligidae) from two new elasmobranch hosts in the Mediterranean Sea, and a comparative redescription of Lepeophtheirus rhinobati Luque, Chaves et Cezar, 1998

In this study, supplementary information on the morphology of the siphonostomatoid copepod Lepeophtheirus acutus Heller, 1865 is given based on new material collected from the ventral body surface and mouth cavity of common guitarfish, Rhinobatos rhinobatos (Linnaeus) and from the branchial cavity of bull ray, Aetomylaeus bovinus (Geoffroy Saint-Hilaire) caught in Iskenderun Bay, Turkey. This is the first report of L. acutus from Mediterranean waters. Key diagnostic characters of both sexes are reported, supported by light and scanning electron microscopy observations. In addition, Lepeophtheirus rhinobati Luque, Chaves et Cezar, 1998, which is closely related to L. acutus and has been reported from the same host genus, Rhinobatos, is reexamined based on paratypes stored in the collections of the United States National Museum of Natural History. Some of the key diagnostic characters which were incompletely known or lacking in the original description of both sexes of L. rhinobati are redescribed and/or presented for the first time.

Occurrence of praniza larvae of a gnathiid (Isopoda, Gnathiidae) on wild-caught orange-spotted grouper, Epinephelus coioides (Hamilton, 1822) (Perciformes, Serranidae), in Lingayen Gulf, Philippines

Praniza larvae of a gnathiid isopod were retrieved from the gills and branchial cavity of wild-caught orange-spotted grouper, Epinephelus coioides (Hamilton, 1822) (Perciformes, Serranidae) in Lingayen Gulf, Philippines. The prevalence and mean intensity of the praniza larvae were 82.3% and 2.2 on the gill filaments and 23.5% and 2.5 in the branchial cavity, respectively. The praniza larva is described and illustrated as there has been no work on the morphology of the parasite in the country where it was collected, to date. This report involves a new record for larval gnathiid infection on E. coioides in the Philippines.

Redescription of Brasilochondria riograndensis (Copepoda, Chondracanthidae) parasitic on flounder, Paralichthys orbignyanus (Actinopterygii, Pleuronectiformes) from South American Atlantic waters

Brasilochondria riograndensis Thatcher et Pereira, 2004 (Copepoda, Chondracanthidae) is redescribed based on newly collected material from the branchial cavity of flounder, Paralichthys orbignyanus (Valenciennes, 1842), from the coasts of Buenos Aires Province, Argentina. A number of details were overlooked and some appendages were misidentified in original description and are included herein. These are: the distribution and the number of setae and spines in the antennule, the armature and segmentation of mandible, maxillule, maxilla, and maxilliped, pedigerous segments and genitoabdomen, in both, females and males. Moreover, the geographical distribution of this parasite species is broadened.

Immunolocalization of NA+,K+-ATPase in the Branchial Cavity During the Early Development of the European Lobster Homarus Gammarus (Crustacea, Decapoda)

We examined the ontogeny of the osmoregulatory sites of the branchial cavity in embryonic and early postembryonic stages of the European lobster Homarus gammarus through transmission electron microscopy, immunofluorescence microscopy, and immunogold electron microscopy using a monoclonal antibody IgGα5 raised against the avian α-subunit of the Na+,K+-ATPase. In mid-late embryos, Na+,K+-ATPase was located along the pleurites and within the epipodite buds. In late embryos just before hatching, the enzyme was confined to the epipodite epithelia. After hatching, slight differentiations of ionocytes occured in the epipodites of larval stages. Na+,K+-ATPase was also located in the ionocytes of the epipodites of larvae exposed to seawater (35.0‰) and to dilute seawater (22.1 ‰). After metamorphosis, the inner-side branchiostegite epithelium appeared as an additional site of enzyme location in postlarvae held in dilute seawater. Within the ionocytes, Na+,K+-ATP-ase was mostly located along the basolateral infoldings. These observations are discussed in relation to the physiological shift from osmoconforming larvae to slightly hyper-regulating (in dilute seawater) postmetamorphic stages. The acquisition of the ability to hyper-osmo-regulate probably originates from the differentiation, on the epipodites and mainly along the branchiostegites, of ionocytes that are the site of ion pumping as evidenced by the location of Na+,K+-ATPase. (J Histochem Cytochem 49:1013–1023, 2001)