Morphology, DNA barcoding and seasonal occurrence of Ergasilus lizae Krøyer, 1863 (Copepoda: Ergasilidae) parasitizing mullets from northwestern Mexico.

Ergasilus lizae Krøyer, 1863 is a parasitic copepod known to infect mullets (Mugilidae) in different parts of the world. It was originally reported from the east coast of North America, but the original description lacks enough detail, making identification with this information difficult. In this study, we provide a redescription of E. lizae found on Mugil curema Valenciennes and M. cephalus Linnaeus, caught in two coastal lagoons of northwestern Mexico during two climatic seasons: warm/rainy and cold/dry. The prevalence of this parasite was higher in the warm season than in the cold season. To facilitate the species identification, new sequences of the barcoding gene (COI mtDNA) of E. lizae were generated and compared against unpublished sequences of E. lizae available in the Barcode of Life Database (BOLD). Our results suggest that the sequences of BOLD possibly belong to a species misidentified as E. lizae.

A new genus of Herpyllobiidae (Copepoda: Cyclopoida) from a deep-living annelid (Polychaeta: Sigalionidae).

A taxonomic study of deep-sea polychaetes collected at a depth of 2,805 m off the northern coast of California revealed a scaleworm of the family Sigalionidae with an attached parasitic copepod. The copepod represents an undescribed genus of the family Herpyllobiidae, comprising mesoparasitic copepods chiefly recorded from polychaetes of the family Polynoidae. Blakerius gen. nov. diverges from the other herpyllobiid genera by its possession of 1) a chalice-shaped ectosoma with several protuberances along the posterior margin and a long cylindrical shaft with a hyaline coating and integumental sculpturing, a short stalk with a small, anteriorly placed sclerotized ring, 2) a relatively large, discoid-shaped endosoma with digitiform process, and 3) attached male copepodids with 3-segmented antennules, containing limbless sac-like males. The new genus is compared with other herpyllobiids. This discovery increases the number of known herpyllobiid genera to six and is the first record of a herpyllobiid parasitizing a sigalionid polychaete.urn: lsid: zoobank.org:pub:5E31FEED-D3EB-460E-AEA4-02A9D3A778D6.

METAZOAN PARASITE COMMUNITY OF THE YELLOW SNAPPER LUTJANUS ARGENTIVENTRIS: FACTORS THAT INFLUENCING SPECIES COMPOSITION AND RICHNESS.

A total of 366 individuals of Lutjanus argentiventris (Peters, 1869) were collected over a 5-yr period (October 2018 to June 2022) from Acapulco Bay, Mexico. Parasite communities in Lutjanus argentiventris were quantified and analyzed to determine the main factors that generate changes in species richness and/or species composition over time. The digeneans and copepods were the best-represented parasite groups. The parasite communities were characterized by a high numerical dominance of ectoparasites, mainly isopod larvae. Species richness at the component community level (9-23 species) was similar to the reported richness in other Lutjanus spp. The parasite communities of Lutjanus argentiventris exhibited high variability in species composition, suggesting that each parasite species may respond differently to environmental changes. However, the species richness and diversity were fairly stable over time; therefore, a clear pattern of interannual variation was not observed. Variations in the community structure probably were due to factors such as host traits (e.g., feeding behavior and body size), and possible interannual differences in environmental factors amplified by the occurrence of the anomalous event of La Niña.

Molecular evidence for a new endemic species of Acartia (Copepoda, Calanoida) from the Southeast Pacific coast.

The loss of biodiversity in marine populations is one of the consequences of the increased events of extreme environmental conditions in the oceans, which can condition the persistence of populations to future scenarios of climate change. Therefore, it is extremely necessary to explore and monitor the genetic diversity of natural populations. In the Southeast Pacific Ocean (SEPO), specifically on the coast of Chile, the presence of the copepod Acartia tonsa has been indicated solely using morphological evidence, due to the absence of genetic information. In the present work, the genetic diversity, population structure and phylogenetic position within the genus Acartia, of populations identified morphologically as A. tonsa, was evaluated by amplification of the mitochondrial cytochrome c oxidase subunit I and nuclear marker 18 s. Our results showed that the populations identified as A. tonsa correspond to a new monophyletic group endemic to SEPO (GMYC = 1.00; PTP = 0.95). The populations showed moderate to high genetic diversity with an incipient structuring between populations and biogeographic zones. Our results suggest that despite the homogenizing effect of the Humboldt Current, isolation by distance and contrasting environmental conditions at different geographic scales have an important influence on the genetic diversity of zooplankton in the SEPO region.

Integrative taxonomy of a new species of Therodamas (Ergasilidae) infecting the Amazonian freshwater fish Leporinus fasciatus (Anostomidae).

Crustaceans of the subclass Copepoda are an important component of the invertebrate aquatic fauna. They occur in all aquatic environments and include some representatives that are free-living organisms and others that have a parasitic lifestyle. The genus Therodamas comprises marine and freshwater copepods whose females are parasites of fish in their adult phase, with only seven species described so far. During a field survey of fish parasites in the Jari River, a large tributary of the Amazon River system, in Brazil, we found a new species of the genus Therodamas infecting Leporinus fasciatus. Therodamas longicollum n. sp. is the second strictly freshwater species known. Phylogenetic analysis showed that the new species is grouped in the family Ergasilidae, and divergence estimates showed that T. longicollum n. sp. diverged from its ancestor at around 66.34 Ma, in the late Upper Cretaceous. Therodamas longicollum n. sp. differs from its congeneric in that it does not have lobes and/or expansion of the anterior neck region. Besides describing a new Therodamas species, thereby increasing the diversity of the genus to eight species, this study points out the existence of a lineage of these copepods that has adapted to the freshwater environment of the Amazon. This study also corroborates the genus Therodamas as part of the family Ergasilidae.

A new Entomolepididae genus and a new species of Spongiopsyllus Johnsson, 2000 (Copepoda, Siphonostomatoida) and their association with Aplysina Nardo, 1834 (Porifera, Demospongiae) in Todos-os-Santos Bay, Bahia, Brazil.

The Entomolepididae family is a small taxon with a very characteristic body morphology and is represented, in the Atlantic Ocean, by three genera and five species. A recent study in Todos-os-Santos Bay, in Bahia State, has revealed a new species of Spongiopsyllus and a new species and genus belonging to the Entomolepididae. The new species of Spongiopsyllus is found in association with the sponge Aplysina cauliformis (Carter, 1882) sampled at the Porto da Barra beach. It is distinguished from its congeners mainly by differences in the segmentation pattern of the antennule, endopod of antenna, and the setation of the maxillule, maxilla and maxilliped. The new genus and species from Parmulodinae Eiselt, 1959 is found in association with the sponge Aplysina solangeae Pinheiro, Hajdu Custódio, 2007, sampled at the Yacht Club Beach. The genus differs from others Parmulodinae mainly due to segmentation pattern of the antennule, endopod of antenna, maxilliped and swimming legs.

A new Bradophila Marchenkov, 2002 (Copepoda, Cyclopoida, Bradophilidae) parasitic on a flabelligerid polychaete from the Chukchi Sea.

The cyclopoid copepod family Bradophilidae includes a few species of mesoparasitic copepods infecting flabelligerid polychaetes. It contains two species of Bradophila Levinsen, 1878, the type genus: B. pygmaea Levinsen, 1878 and B. minuta Boxshall, O'Reilly, Sikorski & Summerfield, 2019, both known from North Europe. Two other genera (i.e., Trophoniphila M'Intosh, 1885 and Flabellicola Gravier, 1918) have some affinities with this family including their host preference. Mesoparasitic copepods are highly specialized, morphologically reduced forms. Part of their body (endosoma) is partially lodged in the host body and the other part is external (ectosoma); both parts are connected by an intersomital stalk. Infection by these copepods can be readily detected by the presence of the egg-carrying ectosoma on the host external surface. From the analysis of flabelligerid polychaetes collected in 2012 from the Chukchi Sea, two ovigerous female individuals of a bradophilid copepod were recorded. These specimens were recognized as representative of an undescribed species of Bradophila. The new species, B. susanae n. sp., shows the generic diagnostic characters and differs from its two other known congeners in several respects, including the cuticular ectosomal ornamentation, body proportions, size of the intersomital stalk, position of the genital pore, and shape and arrangement of egg sacs. Also, the new species ectosomal size range (0.440 - 0.450 µm) falls between the size range of its two known congeners. Our finding expands the known host range of bradophilid copepods to include a new flabelligerid host, Bradabyssa nuda (Annenkova-Chlopina) from the Russsian Arctic region.

New species of Ergasilus von Nordmann, 1832 (Copepoda: Ergasilidae) from the gills of freshwater fishes in Patagonia, Argentina.

A new parasitic copepod, Ergasilus yandemontei n. sp., is described based on 10 adult females collected from the gills of the atherinid silverside Odontesthes hatcheri (Eigenmann), in Lake Pellegrini, Neuquén Province, Patagonia, Argentina. This new copepod species is characterized by having: (i) a 2-segmented endopod on leg 1; (ii) a semi pinnate seta on the terminal segment of the exopod of leg 1; (iii) a reduced leg 5 with a single seta; (iv) aesthetascs on antennule, 1 aesthetasc on the sixth segment and 1 on the fourth segment. Ergasilus yandemontei n. sp. represents the first species described from Patagonian freshwaters. Ergasilus sieboldi var. patagonicus Szidat, 1956 described from Lake Pellegrini, should be considered a synonym of the new species described herein.

A variação da diversidade de microcrustáceos (Cladocera e Copepoda) a jusante de pequenos reservatórios é influenciada por táxons litorâneos / The variation of microcrustaceans diversity downstream of small reservoirs is influenced by litoranean taxa

Testaram-se as hipóteses de que, assim como em reservatórios de grande áreas de superfície, volumes e vazão, em reservatórios pequenos também ocorrem a diluição gradual e contínua da riqueza, da diversidade e abundância de microcrustáceos (Cladocera e Copepoda) a jusante dos mesmos, sem a recomposição da riqueza a jusante pela falta de rios tributários, lagoas marginais e até pelo pequeno porte do riacho, sem condições para o desenvolvimento do potamoplâncton próprio do sistema. Foram estudados dois pequenos reservatórios e seus trechos a jusante, com coletas diárias a cada seis horas em oito pontos de amostragem, sendo dois lênticos e seis lóticos a jusante de cada. Foram encontradas 19 espécies (11 de Cladocera e oito de Copepoda), com destaque para o maior número de espécies litorâneas do que pelágicas, e a maior abundância de cladóceros litorâneos nos pontos a jusante dos reservatórios. Não houve diferença entre os horários, indicando que a escala espacial foi mais importante que a temporal. Houve maiores valores dos atributos ecológicos nos ambientes lênticos, porém houve aumentos significativos de riqueza e diversidade nos últimos pontos dos trechos de riacho, enquanto que a abundância diminuiu gradativamente a jusante. Não foram encontradas correlações significativas da abundância dos táxons com nenhuma variável limnológica (temperatura, pH, oxigênio dissolvido, turbidez, sólidos totais dissolvidos e transparência), indicando pouco ou nenhum efeito destas variáveis. A análise de cluster com distância euclidiana separou dois grandes grupos, o primeiro formado pelo trecho a jusante do primeiro reservatório e o segundo com os demais pontos. Além da presença dos táxons litorâneos vindos dos reservatórios, houve incremento de táxons litorâneos residentes nos riachos. Pode-se concluir que houve uma diluição da abundância das espécies a jusante dos riachos, mas a riqueza e a diversidade permaneceram estáveis devido à contribuição de táxons litorâneos.(AU)

The hypotheses tested were that, as well as in reservoirs of large surface areas, volumes and flow, in small reservoirs there is also a gradual and continuous dilution of the richness, diversity and abundance of microcrustaceans (Cladocera and Copepoda) downstream reservoirs, without the recomposition of richness downstream due to the lack of tributary rivers, marginal lagoons and even the small size of the stream, with no conditions for the development of its own potamoplankton. Two small reservoirs were studied and in their downstream stretches, with daily collections every six hours at eight sampling points, two lentic and six lotic downstream from each. Nineteen species were found (11 from Cladocera and eight from Copepoda), with emphasis on the greater number of coastal species than pelagic ones, and the greater abundance of coastal cladocerans at the points downstream of the reservoirs. There was no difference between the times, indicating that the spatial scale was more important than the temporal scale. There were higher values of ecological attributes in lentic environments, but there were significant increases in richness and diversity in the last points of the stretches of the stream, while the abundance decreased gradually downstream. No significant correlations were found for the abundance of taxa with any physical and chemical variable (temperature, pH, dissolved oxygen, turbidity, total dissolved solids and transparency), indicating little or no effect of these variables. The cluster analysis with Euclidean distance separated two large groups, the first formed by the stretch downstream of the first reservoir and the second with the other points. In addition to the presence of litoranean taxa coming from reservoirs, there was an increase in litoranean taxa resident in streams. It can be concluded that there was a dilution of the abundance of species downstream of the streams, but the richness and diversity remained stable due to the contribution of litoranean taxa.(AU)

A variação da diversidade de microcrustáceos (Cladocera e Copepoda) a jusante de pequenos reservatórios é influenciada por táxons litorâneos / The variation of microcrustaceans diversity downstream of small reservoirs is influenced by litoranean taxa

Testaram-se as hipóteses de que, assim como em reservatórios de grande áreas de superfície, volumes e vazão, em reservatórios pequenos também ocorrem a diluição gradual e contínua da riqueza, da diversidade e abundância de microcrustáceos (Cladocera e Copepoda) a jusante dos mesmos, sem a recomposição da riqueza a jusante pela falta de rios tributários, lagoas marginais e até pelo pequeno porte do riacho, sem condições para o desenvolvimento do potamoplâncton próprio do sistema. Foram estudados dois pequenos reservatórios e seus trechos a jusante, com coletas diárias a cada seis horas em oito pontos de amostragem, sendo dois lênticos e seis lóticos a jusante de cada. Foram encontradas 19 espécies (11 de Cladocera e oito de Copepoda), com destaque para o maior número de espécies litorâneas do que pelágicas, e a maior abundância de cladóceros litorâneos nos pontos a jusante dos reservatórios. Não houve diferença entre os horários, indicando que a escala espacial foi mais importante que a temporal. Houve maiores valores dos atributos ecológicos nos ambientes lênticos, porém houve aumentos significativos de riqueza e diversidade nos últimos pontos dos trechos de riacho, enquanto que a abundância diminuiu gradativamente a jusante. Não foram encontradas correlações significativas da abundância dos táxons com nenhuma variável limnológica (temperatura, pH, oxigênio dissolvido, turbidez, sólidos totais dissolvidos e transparência), indicando pouco ou nenhum efeito destas variáveis. A análise de cluster com distância euclidiana separou dois grandes grupos, o primeiro formado pelo trecho a jusante do primeiro reservatório e o segundo com os demais pontos. Além da presença dos táxons litorâneos vindos dos reservatórios, houve incremento de táxons litorâneos residentes nos riachos. Pode-se concluir que houve uma diluição da abundância das espécies a jusante dos riachos, mas a riqueza e a diversidade permaneceram estáveis devido à contribuição de táxons litorâneos.

The hypotheses tested were that, as well as in reservoirs of large surface areas, volumes and flow, in small reservoirs there is also a gradual and continuous dilution of the richness, diversity and abundance of microcrustaceans (Cladocera and Copepoda) downstream reservoirs, without the recomposition of richness downstream due to the lack of tributary rivers, marginal lagoons and even the small size of the stream, with no conditions for the development of its own potamoplankton. Two small reservoirs were studied and in their downstream stretches, with daily collections every six hours at eight sampling points, two lentic and six lotic downstream from each. Nineteen species were found (11 from Cladocera and eight from Copepoda), with emphasis on the greater number of coastal species than pelagic ones, and the greater abundance of coastal cladocerans at the points downstream of the reservoirs. There was no difference between the times, indicating that the spatial scale was more important than the temporal scale. There were higher values of ecological attributes in lentic environments, but there were significant increases in richness and diversity in the last points of the stretches of the stream, while the abundance decreased gradually downstream. No significant correlations were found for the abundance of taxa with any physical and chemical variable (temperature, pH, dissolved oxygen, turbidity, total dissolved solids and transparency), indicating little or no effect of these variables. The cluster analysis with Euclidean distance separated two large groups, the first formed by the stretch downstream of the first reservoir and the second with the other points. In addition to the presence of litoranean taxa coming from reservoirs, there was an increase in litoranean taxa resident in streams. It can be concluded that there was a dilution of the abundance of species downstream of the streams, but the richness and diversity remained stable due to the contribution of litoranean taxa.

Occurrence of Caligus asperimanus Pearse, 1951 (Copepoda: Caligidae) parasitic Lutjanus spp. (Perciformes: Lutjanidae) in the western South Atlantic.

Sea lice are widespread copepods in marine teleost around the world. In this paper the first record of Caligus asperimanus Pearse, 1951 in the Western South Atlantic is documented parasitizing Lutjanus jocu and Lutjanus vivanus caught from coastal zones of Espírito Santo and Rio de Janeiro State, respectively.

New records and prevalence of metazoan parasites of fish in the southeastern Brazilian region

Hoplias aff. malabaricus is abundant in the Mogi-Guaçu River. The aim of this study was to perform an inventory of the species of metazoan that parasite this species of fish taken from oxbow lakes of the Mogi-Guaçu River. The Mann-Whitney test was used to statistically analyze the possible influence of the sex of the host on the group with the highest parasite richness and the greatest abundance of parasites. Simpson's diversity index was used to determine parasite diversity among the zoological groups of parasites of H. aff. malabaricus with the highest index. A total of 78 specimens of H. aff. malabaricus were examined. Among the zoological groups of metazoans found, the phylum Nematoda had the greatest number of species. Among these, the larval stage of Contracaecum sp. was most abundant. The sex of the host had a significant effect, with parasites more abundant in female fish (Z(U)=0.043; p<0.05). The digenean Parspina argentinensis, the nematodes Procamallanus (S.) iheringi, Rhabdochona acuminata and Hysterothylacium sp. and copepods Vaigamus sp. and Lernaea cyprinacea have not previously been recorded as parasites of H. aff. malabaricus.

Acusicola margulisae n. sp. (Copepoda: Ergasilidae) from freshwater fishes in a Nicaraguan crater lake based on morphological and molecular evidence.

The ergasilid copepod Acusicola margulisae n. sp. is described based on material from three species of cichlid, Amphilophus citrinellus (Günther), Parachromis managuensis (Günther), and Oreochromis sp., and from the poecilid Poecilia mexicana (Steindachner), in the crater Lake Asososca León, Nicaragua. This constitutes the 15th species described in the genus Acusicola Cressey, 1970. The new species differs from all its congeners by the relatively longer first endopodal segment of leg 1, and the size and number of setae on second endopodal segment of leg 1. We provide the first gene sequence for a species of Acusicola. To examine the intraspecific genetic variation of the new species collected from different host species, sequences of the mitochondrial barcode region cox1 were generated. In addition, partial regions of the 18S and 28S ribosomal RNA genes were sequenced and used to infer the phylogenetic relationships of the genus Acusicola within the family Ergasilidae Burmeister, 1835. The phylogenetic trees yielded the isolates of Acusicola margulisae n. sp. as a reciprocally monophyletic lineage, and as the sister taxa of five genera of ergasilid copepods. The genus Ergasilus von Nordmann, 1832 was recovered as a paraphyletic group. These analyses indicate that phylogenetic relationships are not yet well resolved and more representative species and genera of the family are required to provide a robust classification of this highly diverse group of copepods.

A New Species of Rhinergasilus Boeger et Thatcher, 1988 (Copepoda: Ergasilidae) from Gills of Astyanax fasciatus (Cuvier, 1819) (Actinopterygii: Characidae).

PURPOSE: To describe a new species of a parasitic copepod, Rhinergasilus digitus n. sp. (Cyclopoida, Ergasilidae), collected from the gills of the red-tailed lambari Astyanax fasciatus (Characiformes, Characidae) in two tributaries of the Jurumirim Reservoir (Upper Paranapanema River), São Paulo State, Brazil: Ribeirão dos Veados and Paranapanema River. METHODS: Fish were collected using multi-panel gills nets. The gill of each fish was washed and examined in a stereo microscope for copepods. The copepods found were stored in 70% ethanol, cleared in lactic acid, and mounted in Hoyer's medium. Drawings were made with the aid of a Leica microscope DMLS equipped with a drawing tube. RESULTS: The new species differs from its congeneric species, Rhinergasilus piranhus (type-species), in having comparatively biggest body size (body length: 535-598 µm in the new species vs. 237-282 µm in R. piranhus); second antennary segment armed with a minute sensillum near middle of inner margin and a row of spinules on outer margin; third exopodal segment of leg 1 with digitiform process; interpodal plates two and three both ornamented with spinules along posterior margin; leg 5 reduced and represented by two unequal setae. CONCLUSIONS: Based on the morphological differences described above, we erected a new species of Rhinergasilus. Rhinergasilus digitus n. sp. is the second ergasilid described from A. fasciatus, as well as it represents the first report of this genus in a characid fish.

Occurrence of Caligus asperimanus Pearse, 1951 (Copepoda: Caligidae) parasitic Lutjanus spp. (Perciformes: Lutjanidae) in the western South Atlantic / Ocorrência de Caligus asperimanus Pearse, 1951 (Copepoda: Caligidae) parasitos de Lutjanus spp. (Perciformes: Lutjanidae) no Atlântico Sul ocidental

Abstract Sea lice are widespread copepods in marine teleost around the world. In this paper the first record of Caligus asperimanus Pearse, 1951 in the Western South Atlantic is documented parasitizing Lutjanus jocu and Lutjanus vivanus caught from coastal zones of Espírito Santo and Rio de Janeiro State, respectively.

Resumo Os piolhos marinhos são copépodes abrangentemente relatados em teleósteos marinhos ao redor do mundo. Neste estudo, é documentado o primeiro registro de Caligus asperimanus Pearse, 1951, no Atlântico Sul Ocidental, parasitando Lutjanus jocu e Lutjanus vivanus capturados nas zonas costeiras do Espírito Santo e Rio de Janeiro, respectivamente.

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.

A New Genus of Ergasilidae (Copepoda: Cyclopoida) from the Gills of Astyanax fasciatus (Cuvier, 1819) (Actinopterygii: Characidae).

PURPOSE: To describe a new genus and a new species of an ectoparasitic ergasilid (Copepoda, Ergasilidae) parasite of the red-tailed lambari, Astyanax fasciatus, from Jurumirim Reservoir (Upper Paranapanema River), São Paulo State, Brazil. METHODS: The host fish were collected using multi-panel gill nets. The gill of each fish was washed and examined in a stereo microscope for copepods. The copepods found were stored in 70% ethanol, cleared in lactic acid, and mounted in Hoyer's medium. Some specimens were dissected in glycerol medium and then each dissected part was mounted on individual slides. RESULTS: A new genus and a new species of Ergasilidae were described herein. Duoergasilus basilongus n. gen., n. sp. differs from all other ergasilids in having the second and third pair of biramous swimming legs (P2 and P3) each with a 2-segmented endopod, and by its unique maxillary basis, resembling a whip. CONCLUSIONS: The new copepod is the first 'four-legged' ergasilid with all swimming legs having a 2-segmented endopod. Duoergasilus basilongus n. sp. represents the first record of a parasitic copepod on A. fasciatus in Jurumirim Reservoir, as well as its represents the first description to species level of an ergasilid infecting an Astyanax species in Brazil. A key to the 28 accepted genera of Ergasilidae is provided.

A New Species of Neoalbionella (Copepoda: Siphonostomatoida: Lernaeopodidae) From Skin of the Gulper Shark, Centrophorus granulosus (Squaliformes: Centrophoridae) In the Northern Gulf of Mexico.

Using light and scanning electron microscopy of male and female copepods, we herein describe a new species of Neoalbionella Özdikmen, 2008 (Copepoda: Lernaeopodidae), Neoalbionella benzipirata n. sp., infecting the skin of the gulper shark, Centrophorus granulosus (Bloch and Schneider, 1801), in the northern Gulf of Mexico. Females of the new species were assigned to Neoalbionella by having 3 setae on the maxillule lateral palp (vs. 2 setae in Lernaeopoda Nordmann, 1832) and a single accessory denticle on the maxilliped subchela claw (vs. ≥2 denticles in Lernaeopoda). Females of the new species resemble those of Neoalbionella longicaudata ( Hansen, 1923 ) Özdikmen, 2008 but can be differentiated from them and those of all congeners by having a unique configuration of 16 dorsocephalic sensilla; an antennule terminal segment having 6 apical setae comprising tubercles 1 and 3, digitiform seta 4, 2 subequal setae of complex 5, and flagelliform seta 6; an antenna exopod with a thickened dorsal ridge, smooth (convex) outer surface with 2 short papillae, and rugose (concave) inner surface plus a terminal endopodal segment having a large dorsal hook, medial spine, bifid distal tubercle, and spinulose ventral process; a mandible having the formula P1, S1, P1, S1, P1, S1, B5; and a single pair of anterolateral spines on the mouth cone labium. Males attached to the posteroventral surface of the females' genital trunk were assigned to Neoalbionella by having tapered (not inflated) caudal rami directed posteroventrally. They were differentiated from previously reported congeneric males by having an antennule with the same number and configuration of apical setae as the female; an antenna with a spatulate exopod having minute spinules along its apex plus a terminal endopodal segment with components the same as the female; a mandible with formula P2, S1, P1, S1, B5; a labium with 1 pair of anterolateral spines like the female; and a conspicuous mediative process with bifid tip. Detail of the dorsocephalic shield (in females) and mouth cone labium (in both sexes) previously had not been used to diagnose Neoalbionella spp. We also dissected voucher specimens of " Neoalbionella longicaudata" (collected from gulper sharks in the western Pacific Ocean off Japan by Shiino in 1956), which we morphologically diagnosed as an innominate species, Neoalbionella sp. This is the first report of a species of Neoalbionella from the Gulf of Mexico and the second species of Neoalbionella reported from C. granulosus, a deepwater shark seldom encountered and surveyed for parasitology.

Ergasilus tipurus n. sp. (Copepoda: Ergasilidae), A Parasite of Brazilian Amazon Fish Species.

INTRODUCTION: Copepods are common components in all types of fish assemblages, being present in fishes of all ecosystems. The Ergasilidae Burmeister, 1835 is one of the biggest families in the order Cyclopoida Burmeister, 1834, with the majority of species found on freshwater fishes. MATERIAL AND METHODS: Ergasilus tipurus n. sp. is described from the nasal fossae of Calophysus macropterus and Sorubim lima captured in the rivers Guaporé and Mamoré in the State of Rondônia, Brazil, and from the nasal fossae and the gills of Rhaphiodon vulpinus collected from floodplain lakes of the Solimões River in the State of Amazonas, Brazil. RESULTS: The new species differs from all known species of Ergasilus from Brazilian waters by: (1) antennule setal formula 3:7:3:4:2:5; (2), having three-segmented first endopod of leg I; and (3) having leg V with a single well-developed segment with one middle distal setae, two distal setae placed laterally and two basal papillae, each provided with a simple seta. DISCUSSION: From all Ergasilus species described in the neotropics, this is the first species that can be found parasitizing the gills and nasal fossae of the reported hosts.