Species Of Parasitic Copepods Research Articles

Peracetic acid treatment of squid eggs infected with parasitic copepod (Ikanecator primus gen. et sp. nov.)

Having been successfully bred in semi-intensive and intensive aquaculture systems, oval squids of the Sepioteuthis lessoniana species complex are emerging as promising candidates for research and industry. Nevertheless, information about pathogens and diseases that may affect squid aquaculture remains sparse. In this study, we identify new parasitic copepod species that causes squid mortality and decreases squid hatching rates, and we also offer a solution to eliminate the pathogen during incubation of squid eggs. The newly discovered copepod Ikanecator primus gen. et sp. nov. was identified on oval squid eggs for the first time using both morphological and molecular diagnostic markers. In the genomes of the copepod and associated microbiome, we identified multiple genes for enzymes involved in cephalopod eggshell degradation in genomes of the copepod and associated microbiome. Furthermore, we conducted experiments to assess efficacy of peracetic acid in inhibiting the I. primus gen. et sp. nov. both in vitro and in vivo using immersion treatment. We established that a 2-min exposure to a concentration of 250 μl/L of peracetic acid containing product (PAA-product; 35 mg/L PAA and 15 mg/L H2O2) inhibited the development of nauplii in vitro. All parasites exposed to a concentration of 500 μl/L of PAA-product (70 mg/L PAA and 30 mg/L H2O2) were eliminated within two minutes. On top of this, the immersion treatment with 500 μl/L of PAA-product (70 mg/L PAA and 30 mg/L H2O2) improved survival of squid embryos and increased size of squid hatchlings compared with control and the immersion treatment with 125 μl/L of PAA-product (17.5 mg/L PAA and 7.5 mg/L H2O2) and the immersion treatment with 250 μl/L of PAA-product (35 mg/L PAA and 15 mg/L H2O2). These findings suggest that PAA holds a great potential as inhibitor and controller of parasitic copepod infections and for overall health management in cephalopod culture.

Specifics of <i>Anisakis simplex</i> larvae infection in the Pacific herring <i>Clupea pallasii</i> Valenciennes, 1847 from Lake Tunaicha

The purpose of the research is to analyze specifics of Anisakis simplex larvae infection in the body cavity of the lake Pacific herring in Lake Tunaicha (from materials of 1980 to 1995).Materials and methods. Conventional parasitological methods were used for collecting the material. The dissection recorded the number of nematodes in the fish. Parasitological studies of the herring from Lake Tunaicha (southern Sakhalin) were conducted from 1980 to 1995. A total of 4,438 fish caught in the Krasnoarmeyskaya channel and Lake Tunaicha were examined.Results and discussion. The parasite fauna in the herring from Lake Tunaicha included six parasite species of which two nematode species (Anisakis simplex l., Hystorethylacium aduncum l.), one acanthocephala species (Corynosoma strumosum juv.), one trematode species (Brachyphalus crenatus) and two parasitic copepod species (Ergasilus wilsoni and E. hypomesi). Among all the above species, A. simplex larvae were of greatest interest for study. The helminth is a typical species of the Pacific herring and poses a threat to human and animal health. The results of the studies found no difference in the infection of herring females or males in Lake Tunaicha. A change in the infection rate was demonstrated in the herring by age and linear dimensions depending on the fish life cycle (spawning and wintering migration periods). The first cases were recorded for herrings infected with Anisakis sp. larvae sized from 14 cm.

Correlation of endemicity between monogenean trematode, Microcotyle sebastis, and parasitic copepods in Korean rockfish, Sebastes schlegelii, from a fish farm in Tongyeong-si, Gyeongsangnam-do, Korea.

Infestations of parasites, particularly those caused by copepods and monogeneans, are a major hindrance to aquaculture and have a big negative economic impact. Sebastes schlegelii, a farmed Korean rockfish, is particularly prone to copepods and monogeneans. This study comprehended how parasitic copepods and rockfish from a farm in Tongyeong-si, Gyeongsangnam-do, Korea, are related to the monogenean trematode Microcotyle sebastis. Our research revealed that monogeneans predominated, with a rate of 98.4% and an average infection intensity of 7 per infected fish. With an average infection intensity of 4 per sick fish, the infection rate for parasitic copepods was equally considerable, coming in at 91.7%. The high co-infection rate of both parasite families, at 90.8%, is noteworthy. Furthermore, Lepeophtheirus elegans and Peniculus truncatus, 2 parasitic copepod species, were discovered to have M. sebastis eggs attached to their bodies. This demonstrates a connection between parasitic copepod infestations in farmed Korean rockfish and the monogenean trematode M. sebastis. These discoveries highlight the necessity for creating more potent parasite control methods for the aquaculture sector and shed light on the intricate relationships between various parasite species.

Mining Lepeophtheirus salmonis RNA-Seq data for qPCR reference genes and their application in Caligus elongatus

Lepeophtheirus salmonis and Caligus elongatus are two parasitic copepod species posing a significant threat to salmonid aquaculture. Consequently, several gene expression studies are executed each year to gain new knowledge and treatment strategies. Though, to enable accurate gene expression measurements by quantitative real time PCR, stable reference genes are needed. Previous studies have mainly focused on a few genes selected based on their function as housekeeping genes, as these are often stably expressed in various cells and tissues. In the present study, however, RNA-sequencing data from 127 L. salmonis samples from different life stages and diverse environmental conditions were used to identify new candidate reference genes displaying low variation. From this, six genes were selected, and the stability validated by qPCR on samples from different life stages. Since neither a genome nor comprehensive RNA sequencing data are available for C. elongatus, homologous genes to those identified for L. salmonis were identified within a C. elongatus transcriptome assembly and validated by qPCR in different life stages. Overall, the genes eukaryotic translation initiation factor 1A (EIF1A) and serine/threonine-protein phosphatase 1 (PP1) displayed the highest stability in L. salmonis, while the combination of PP1 and ribosomal protein S13 (RPS13) was found to have the highest stability in C. elongatus. These genes are well-suited reference genes for qPCR applications which allow for accurate normalization of target genes.

Embryonic and post-embryonic development in the parasitic copepod Ive ptychoderae (Copepoda: Iviidae): Insights into its phylogenetic position.

Parasitic copepods are frequently discovered in many marine animals, and they exhibit great species diversity with remarkable morphological adaptations to their parasitic lifestyle. Similar to their free-living relatives, parasitic copepods usually develop through complex life cycle, but they eventually transform into a modified adult form with reduced appendages. Although the life cycle and distinct larval stages have been described in a few species of parasitic copepods, particularly those infecting commercially valuable marine animals (such as fishes, oysters, and lobsters), very little is known about the developmental process of the species that transformed into extremely simplified adult body plan. This paucity also causes some difficulties when investigating the taxonomy and phylogeny of this kind of parasitic copepods. Here we describe the embryonic development and a series of sequential larval stages of a parasitic copepod, Ive ptychoderae, which is a vermiform endoparasite living inside the hemichordate acorn worms. We devised laboratory regimes that enable us raising large quantity of embryos and free living larvae, and obtaining post-infested I. ptychoderae samples from the host tissues. Using defined morphological features, the embryonic development of I. ptychoderae can be categorized into eight stages (1-, 2-, 4-, 8-, 16- cell stages, blastula, gastrula, and limb bud stages) and the post-embryonic development comprises six larval stages (2 naupliar and 4 copepodid stages). Based on the comparisons of morphological characters in the nauplius stage, our results provide evidence to support that the Ive-group is more closely related to the Cyclopoida, which represents one of the two major clades that contain many highly transformed parasitic copepods. Thus, our results help to resolve the problematic phylogenetic position of the Ive-group in previous study based on analysis using 18S rDNA sequences. Combining with more molecular data, future comparative analyses on the morphological features of copepodid stages will further refine our understanding of the phylogenetic relationships of parasitic copepods.

A new species of Colobomatus Hesse, 1873 (Copepoda: Philichthyidae) parasitic in the interorbital canals of the Caitipa mojarra Diapterus rhombeus (Cuvier, 1829) (Actinopterygii: Gerreidae) from Sepetiba Bay, southeastern Brazil.

A new species of parasitic copepod, Colobomatus deborae n. sp., belonging to the cyclopoid family Philichthyidae Vogt, 1877, is proposed based on adult female specimens collected from the interorbital canals of the Caitipa mojarra Diapterus rhombeus (Cuvier) (Gerreidae) from Sepetiba Bay, off the State of Rio de Janeiro, southeastern Brazil. The new species closely resembles six species of Colobomatus Hesse, 1873, but differs from these close congeners based on the combination of the following characters: lateral cephalic processes forked basally with sharp tips, midventral cephalic process representing about one third of the length of the laterals, thoracic processes forked and caudal rami with a pair of unequal processes. Together with the new species described in the present study, the philichthyid fauna of Brazil rises to 10 species reported from 14 Brazilian marine fish species. This is also the third report of Colobomatus in a gerreid fish, but the first species found parasitizing the genus Diapterus.

Lepeophtheirus mondacola sp. nov. (Copepoda; Caligidae) parasitic on the shortjaw leatherjacket Oligoplites refulgens (Teleostei; Carangidae) in the Gulf of California, Mexico.

A new species of parasitic copepod, Lepeophtheirus mondacola sp. nov. (Siphonostomatoida; Caligidae), is described based on female and male specimens obtained from the shortjaw leatherjacket Oligoplites refulgens (Actinopterygii; Perciformes; Carangidae), captured in the southeastern Gulf of California off northwestern Mexico. The new species can be separated from its congeners by a combination of characters that includes: adult female with a subquadrate genital complex bearing slightly protruded posterolateral corners, two indistinct somites on the abdomen which, when combined together, is about two times longer than wide, a caudal ramus that is twice as long as it is wide, a postantennal process comprising a stout base and short claw, a dentiform process of the maxillule with two unequal tines, a maxilliped with a stout protopod and subchela, a sternal furca with a pair of bifurcated tines, a leg 3 exopod composed of 2 segments, five setae on the distal endopodal segment of leg 3 and a leg 4 exopod composed of three segments and armed with one long and two short apical spines on the distal exopodal segment; adult male with a suborbicular genital complex, an abdomen composed of one short and one long, indistinctly separated somites, a caudal ramus that is twice as long as it is wide, a stout postantennal process, a small triangular process at the base of the inner tine of the maxillulary dentiform process and a 3-segmented exopod on leg 4. Lepeophtheirus mondacola sp. nov. represents the first record of a species of Lepeophtheirus from a member of Oligoplites and the second caligid species reported from O. refulgens.

Redescriptions of two parasitic copepod species from the rudis rattail, Coryphaenoides rudis (Pisces, Macrouridae) from Taiwan

Abstract Two parasitic copepods, Lateracanthus quadripedis Kabata & Gusev, 1966 and Parabrachiella annulata (Markevich, 1940) (Lernaeopodidae), were found on a deep-sea rudis rattail, Coryphaenoides rudis Günther, 1878 (Macrouridae) collected from the Xingang fishing port in Chenggong Town, Taitung County, in south-eastern Taiwan. Lateracanthus quadripedis was found attached to the walls of the branchial cavity of the fish, whereas P. annulata was collected from the body surface. This paper also provides a full description of these two copepod species to elucidate possible geographical variations in their morphology. Remarkably, our specimens of both copepods are more similar to those from the Galápagos Islands than to those from the Aleutian-Deep or Japan.

Two New Parasitic Copepod Species, Clavella (Lernaeopodidae) and Haemobaphes (Pennellidae), on the Nototheniid Fish Patagonotothen cornucola (Richardson, 1844) from the Strait of Magellan, Southern Chile.

The parasitic diversity on the intertidal fish of the Southern American Cone is barely known. The present study describes two new parasitic copepod species, a Clavella and a Haemobaphesfound on the nototheniid fish Patagonotothen cornucola. The fish were collected from the intertidal zone of the Strait of Magellan, Southern Chile. The copepods were found on the fins and in the gill chamber of the fish, which were morphologically analyzed using optical and electronic microscopy. Clavella cornucola sp. nov. and Clavella bowmani are similar but differ in the number of setae found on the maxillule (two setae on the inner lobe vs. three on C. bowmani), and a pad of spinules on the dorsal margin as opposed to the outer lobe (no pad vs. one pad, respectively). Haemobaphes puntaarenensis sp. nov. is distinguished from its congeners based on the lobe shapes of the head and the clear separation between the pedigerous somites (first, second, and third). The maxilla on H. puntaarenensis sp. nov. lacks a pad of spinules on the second segment, but it is found in all the other congeneric species. Clavella cornucola sp. nov. is the 10th species of the genus in Chile, whereas Haemobaphes puntaarenensis sp. nov. is the first species of the genus recorded in Chile and the Southern Cone coasts.

Паразиты рыб горных озер бассейна Верхней Колымы. 1. Озера большой и малый Дарпир.

The first data on the parasite fauna of fish from the mountain lakes Bolshoy and Maly Darpir at the southern spurs of the Chersky Ridge (Momsky District, Yakutia) are presented. 7 species of fish have been studied, in which 34 species of parasites have been found: 33 species of helminths and 1 species of parasitic copepods, belonging to 22 genera, 16 families, 12 orders, 7 classes of 4 types of the animal kingdom. Trematodes completely dominate by the number of species among helminths (16 species); cestodes are half as many (8 species); these are followed by nematodes and spiny-headed worms (5 and 4 species, respectively). The greatest variety of parasites was found in the East Siberian grayling (22 species) and the Arctic char (19 species). Next to the latter in terms of the number of parasite species, there went the Kolyma sculpin (13 species), round whitefish (10 species each), sucker (9 species), eelpout, and common minnow (7 species each). Only one parasite species, the Neoechinorhynchus salmonis Ching, 1984 spiny-headed worm, is common for all studied fish. The second species of spiny-headed worms, Pseudoechinorhynchus borealis (Linstow, 1901), not found only in the round whitefish, was first recorded in fish of the Okhotsk-Kolyma area and in the sucker as a new definitive host.

Two new species of Colobomatus Hesse, 1873 (Crustacea: Philichthyidae) parasitic in the interorbital canals of Holocentrus spp. (Holocentriformes: Holocentridae) in the South Atlantic Ocean.

Two new species of parasitic copepods of the genus Colobomatus Hesse, 1873 (Cyclopoida) are proposed based on specimens collected from the squirrelfishes (Holocentridae) off the coast of Rio de Janeiro, Brazil. Colobomatus luquei n. sp. from the interorbital canals of Holocentrus adscensionis (Osbeck) can be distinguished from its closest congeners by the following combination of characters in the adult female: first to fourth thoracic somites fused, two pairs of thoracic processes, fifth pedigerous somite without processes, and process in the third abdominal somite not transpassing the margins of the caudal rami; and in the adult male: antenna with two elements in the second endopodal segment, leg 1 with three spines and three setae in the second endopodal segment, and leg 2 with three spines and three setae in the second exopodal segment. Colobomatus freirei n. sp. from the interorbital canals of Holocentrus rufus (Walbaum) can be distinguished from its closest congeners through the possession of an anterior pair of thoracic processes four times longer than the posterior pair. The two new species described herein are the first representatives of the family Philichthyidae found to parasitize fish of the order Holocentriformes.

A Redescription of Lepeophtheirus longipes Wilson, 1905 (Copepoda; Caligidae) Parasitic on Giant Sea Bass, Stereolepis gigas Ayres, 1859 (Polyprionidae), off California

The giant sea bass (GSB), Stereolepis gigas Ayres, 1859, is the largest teleost (exceeding 2 m in length and 200 kg in weight) and megacarnivore found in California kelp forest communities. Overfishing of GSB in the late 1920s crashed the population off California and in 1996 it was classified as an International Union for Conservation of Nature (IUCN) critically endangered species. Recently, three GSB were collected off San Onofre, California and held at the Southern California Marine Institute in San Pedro. Two of the three GSB were infected with Lepeophtheirus longipes Wilson, 1905 (Siphonostomatoida; Caligidae), a poorly described species of parasitic copepod previously recorded from the GSB and purportedly on other fish hosts. In this study, a detailed redescription of the female and the first description of the male of L. longipes are provided and all records of Lepeophtheirus longipes are reviewed. The latter revealed that L. longipes is host specific to GSB. Lepeophtheirus longipes is distinguished from its congeners by a combination of female characters that includes: (1) genital complex with prominent posterolateral lobes and is about half the length of the cephalothorax and just over two times longer than the cylindrical, indistinctly 2-segmented abdomen; (2) an antennule with a small conical process on the proximal segment; (3) maxillule with an outer conical process at the base of the dentiform process; (4) sternal furca with pointed and slightly splayed tines; (5) first exopodal segment of leg 3 with a terminal spine; and (6) third exopodal segment of leg 4 with three unequal apical spines.

Xarifiid Copepods (Copepoda: Cyclopoida: Xarifiidae) Parasitic in the Coral Psammocora columna Dana, 1846 from Taiwan.

Simple SummaryThe coral reef is the crucial habitat for numerous marine creatures, and scleractinian corals are building blocks of this community. Therefore, the health condition of scleractinian corals is an essential factor for the sustainability of coral reef ecosystems. Recent studies indicate that global warming, seawater acidification as well as coral diseases are the main threats to scleractinian corals. In addition, coral endoparasites may impact the health of scleractinian corals by consuming coral tissues and potentially transferring disease pathogens. However, we have limited knowledge about the distributions of coral endoparasites across scleractinian corals. It may lead to the assessment bias on the health condition of the coral reef community due to no consideration on the impact of the interaction between corals and their endoparasites. Here, we performed an elaborate survey on a widely distributed scleractinian coral species, Psammocora columna, and discovered two new parasitic copepod species, Xarifia yanliaoensis and Xarifia magnifica. We also summarized a classification key of morphological characteristics for the identification of Xarifia copepods in Psammocora corals. The findings of this study present new records of copepod-coral relationships in the Indo-West Pacific for the biological resource database. Furthermore, these are the footstone knowledge for further studies on coral reef conservation.A comprehensive knowledge of relationships between coral and coral-associated organisms is essential for the conservation studies of the coral reef community, yet the biodiversity database of coral-inhabiting copepods remains incomplete. Here we surveyed in a widely distributed scleractinian coral, Psammocora columna Dana, 1846, and newly discovered two endoparasitic copepod species, Xarifia yanliaoensis sp. nov. and Xarifia magnifica sp. nov. These two new species are described based on specimens collected in Taiwan, and they share several common morphological characters of Xarifia copepods, i.e., region dorsal to fifth legs having three posteriorly directed processes unequally. However, X. yanliaoensis sp. nov. is distinguishable from other species by the morphology of the endopods of legs, antenna, maxilla, and maxilliped (in both genders). The morphological characters of X. magnifica sp. nov. are the endopods of legs, leg 5, and maxilliped in the male. Including the two new species described in the present work, the genus Xarifia Humes, 1960 belongs to the cyclopoid family Xarifiidae Humes, 1960 currently consists of 94 species, and eight of them live in association with the Psammocora coral. A comparison table and a key to the species of Xarifia from Psammocora corals are given herein.

Three species of copepods parasitic on the blue mackerel Scomber australasicus Cuvier (Actinopterygii: Perciformes: Scombridae) from southern Japan, with description of a new species Colobomatus itoui n. sp. (Cyclopoida: Philichthyidae).

The blue mackerel Scomber australasicus is one of the major commercial fishes consumed in southern Japan. Three species of parasitic copepods were collected from S. australasicus in the East China Sea off the west coast of Kyushu Island, southern Japan. These copepods are each characterized based on the females: Pumiliopes scombri (Bomolochidae) differs from its congeners by the presence of fine ventral spinules on legs 2 to 4; Colobomatus itoui n. sp. (Philichthyidae) is characterized by having the cephalosome with a pair of dorsal hemispherical cephalic protrusions but without an apical cephalic process and the anal somite with a pair of posterolateral protrusions with a smooth tip; and Caligus kanagurta (Caligidae) is distinguishable from its congeners accommodated in the Caligus diaphanus-group by bearing an atypical bulged leg 4 with long protruded pectens. The collection of C. kanagurta in Japanese waters represents its new country record. Parasitic copepods reported from S. australasicus and its related species S. japonicus from the western Pacific Ocean are tabulated.LSID urn:lsid:zoobank.org:pub:382569AD-5188-4443-AAA8-1C2DB4FE2689.

Parasitological Records of Eight Rockfish Species (Scorpaeniformes: Scorpaenidae) from Pacific Baja California, Mexico

This study reports parasitological records of eight species of marine rockfishes (Sebastes auriculatus, S. chlorostictus, S. umbrosus, S. miniatus, S. atrovirens, S. constellatus, S. serranoides, and Scorpaena guttata) collected from Todos Santos bay and San Quintin coast, Baja California, Mexico. The vermilion rockfish, S. miniatus, showed the highest parasite species richness (two species of monogeneans, two species of digeneans, three species of nematodes and one species of copepods), while the lowest richness was found in S. atrovirens and S. umbrosus (one species of copepod and one species of nematode, respectively). The species S. auriculatus, S. chlorostictus, S. constellatus, S. serranoides, and S. guttata showed a richness of up to four parasite species. Seven of the eight fish species (except S. atrovirens) presented larval stages of nematodes Anisakis sp., Pseudoterranova sp. and Hysterothylacium sp. (prevalences ranging from 8.3 to 100%), which were found in the fish mesentery (guts). The parasite species with the highest prevalence values (>80%) were found in S. miniatus (Anisakis sp.), S. guttata (Anisakis sp. and Hysterothylacium sp.), S. umbrosus (Anisakis sp.), S. auriculatus (Anisakis sp.), and S. constellatus (Anisakis sp.). The most abundant parasite species (>4 ind./host) were recorded in S. guttata (Anisakis sp. and Hysterothylacium sp.), S. umbrosus (Anisakis sp.), S. constellatus (Parabothriocephalus sagitticeps), and S. miniatus (Anisakis sp.). The parasite species with the highest intensity of infection values (>5 ind./host) were found in S. constellatus (P. sagitticeps), followed by S. guttata (Anisakis sp., Hysterothylacium sp.), S. umbrosus (Anisakis sp.), and S. serranoides (Microcotyle sebastis). The present study, in addition to listing the helminths and parasitic copepod species (and providing quantitative data on them) of eight commercially important scorpaenid fish species in the northwestern Mexico, can also serve as a baseline for future parasitological studies on these fish species.

A new species of parasitic copepod of the genus Lernaeenicus Lesueur, 1824 (Siphonostomatoida: Pennellidae) from the torpedo scad Megalaspis cordyla (Linnaeus) off Kerala coast of Arabian Sea, India

ABSTRACT A new species of parasitic copepod of the genus Lernaeenicus Lesueur, 1824 (Siphonostomatoida: Pennellidae) parasitizing the torpedo scad Megalaspis cordyla (Linnaeus) collected from the Arabian Sea, off Kerala coast, India is described and illustrated. The new species, Lernaeenicus megalaspis sp. nov., can be distinguished from its other 32 congeners by the following features: (i) cephalosome 1.5 times longer than broad; (ii) presence of three stout posterior horns on the cephalosome, one median and two lateral, all sub-similar and apically round and blunt; (iii) neck 4.6 times as long as trunk; (iv) abdomen slightly longer than trunk; (v) 4-segmented antennule, and (vi) maxilla, third segment narrow, longer than second, segment 1 slightly broader than others and lateral border with two small spine. Publication LSID: lsid:http://zoobank.org:pub:8B4CD87A-0821-4F2A-9159-6338BDA85D3B

Caligus tunisiensis n. sp. (Copepoda: Caligidae) parasitic on the painted comber Serranus scriba (L.) (Perciformes: Serranidae) from the Mediterranean Sea, off the Tunisian coast.

A new species of parasitic copepod, Caligus tunisiensis n. sp. (Caligidae), is described based on two female specimens collected from the gills of the painted comber, Serranus scriba (L.), caught in the Mediterranean Sea, off the Tunisian coasts. The new species belongs to the Caligus productus-species group established by Boxshall & Gurney (1980) as it shares the following set of character states: (i) antenna with well-developed posterior process on proximal segment; (ii) posterior margin of distal exopodal segment of leg 1 lacking typical plumose setae, or retaining single vestigial seta; and(iii) 2-segmented exopod of leg 4 armed with IV spines on compound distal exopodal segment. Detailed morphological comparisons between the new species and the core members of the C. productus-species group revealed that the new species closely resembles with C. productus Dana, 1852 and C. temnodontis Brian, 1924. However, the new species can be distinguished from its congeners in having: (i) a female maxilliped bearing a prominent bi-lobate myxal process, opposing tip of the claw; (ii) leg 4 protopod ornamented with a patch of spinules on the posterolateral surface; and (iii) an abdomen ornamented with two rows of minute spinules at the posterolateral corners.

New species of Acanthochondria Oakley, 1930 and Chondracanthus Delaroche, 1811 (Copepoda: Cyclopoida: Chondracanthidae) parasitizing marine fishes from Indian waters

Abstract This paper describes two new species of parasitic copepods of the family Chondracanthidae H. Milne Edwards, 1840. Acanthochondria krishnai sp. n. is described from Dollfus' stargrazer, Uranoscopus guttatus Cuvier, collected from Muttom and Colachel, Tamil Nadu, and Chondracanthus kabatai sp. n. from Silvery john dory, Zenopsis conchifer Lowe, collected from Neendakara, Quilon, Kerala, both along the southwest coast of India. Both the species are described and illustrated based on the fresh female and male specimens collected from India. Both the species are the first Indian representative of the respective genera. The checklist of Indian species of the family Chondracanthidae is also presented.

Clupeid fish hosts a Peniculus sp. (Pennellidae, Siphonostomatoida, Copepoda)—First report on new host and season dependent prevalence

Pennellid copepod Peniculus fistula fistula (Nordmann, 1832) (Synonym: Peniculus fistula Nordmann, 1832, Aphia ID: 745880), a worldwide distributed species, has been recovered from at least 19 teleost families. The present paper reports for the first time from the Malabar coast (South India), not only the existence of a new host family, Clupeidae, hosting this parasitic copepod species (P. fistula fistula) but also their season dependent hosting. A total of 123 marine fish species, belonging to 77 genera and 38 families surveyed along the Malabar coast, only the clupeid, Anadontostoma chacunda (Hamilton, 1822) was shown to be infected by this copepod species; all the recovered (copepod) parasites were invariably found attached at the mid portion of the caudal fin lobes and lying parallel to the host body, indicating the strict site-specific parasitisation. There is a discrete seasonality in the prevalence (P<0.05) as the sign of infection was noticed during the period from September to May with relatively high prevalence during winter months (November–January). During the monsoon months (June–August), the host fish was found completely free from Peniculus infection. Interestingly, all the 229 recovered specimens (P. fistula fistula) were gravid females having paired uniserrate egg sacs with the length more than its own body length.

Description of Echthrogaleus spinulus n. sp. (Copepoda: Pandaridae) parasitic on a torpedo ray from the central Pacific Ocean utilising a morphological and molecular approach.

A new species of parasitic copepod, Echthrogaleus spinulus n. sp. (Pandaridae), is described from the torpedo ray Tetronarce tokionis (Tanaka) (Torpedinidae) captured in pelagic Hawaiian waters. The new species has pediger 4 bearing large dorsal plates with denticles on posterior margin, genital complex with posterolateral lobes widely curved medially and overlapping, leg 4 exopod incompletely 3-segmented, and the largest body size (maximum length 16 mm from anterior rim of frontal plates to tip of caudal rami, excluding setae). This morphology does not match any of the seven valid species of Echthrogaleus Steenstrup & Lütken, 1861. Analysis of 28S rDNA sequences separated the new material from the Central Pacific from samples of E. coleoptratus in the Atlantic and Eastern Pacific Oceans. However, due to the lack of DNA sequences in the databases, the new 28S rDNA sequence cannot used to confirm the species identity. The unique morphological characteristics of the Central Pacific female copepods combined with 28S rDNA sequencing was used as a basis to validate the new species.