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Despite their great interest for the integrated management of water resources, information on the ecology of aquatic oligochaetes is still sketchy in Cameroon. The present study aims at contributing to the knowledge on the distribution, microhabitat and life history of Naididae tubificids taxa in some eight water bodies of the city of Yaounde. A total of 132 samples were analysed and the morphospecies Branchiura spp. and Limnodrilus spp. were identified. The most abundant species were Branchiura spp. with 2035 individuals versus 880 Limnodrilus spp. Both of them demonstrate low seasonal variations. It appeared that, these annelids are more abundant on clay-rich soils than on sand and the herbarium. Assessment of the organic pollution index indicates an organic pollution of the sampled waters ranging from moderate to high (3.67-2). The redundancy canonical analysis shows that Branchiura spp. are more present in saline waters revealing high organic pollution factors variables. During the study period, some 10 individuals of Limnodrilus spp. presented a shrunken tail. That reveals a strong environmental pressure due to the action of predators or the presence of heavy metals in the aquatic system evaluated. All these characteristics indicate a high pollution and predation pressure in the milieu. Key words: Annelids oligochaete, ecology, bottom nature, polluted water.

Chonopeltis lisikili Van As and Van As, 1996 was original described from the Eastern Caprivi (Namibia) and the Okavango System (Botswana), collected from five Synodontis Cuvier, 1816 (Mochokidae) species. This fish genus is endemic to Africa, with 130 valid species, making it one of the most species-rich and widely distributed mochokid catfish family. During parasitological surveys conducted in the Phongolo River (South Africa), a Chonopeltis Thiele, 1900 species was collected from Synodontis zambezensis Peters, 1852. In total, 21 adult females, four adult males, as well as representatives of the larval developmental stages were found. After morphological comparison, this branchiuran was identified as C. lisikili. This paper provides additional information on body measurements and morphological information of all the life stages of the Phongolo material. Information on Chonopeltis material collected from the Okavango River, Botswana, not yet published is also included as well as the first molecular characterisation of a Chonopeltis species using COI and 18 S rRNA partial sequencing. The endemicity of the host and fish lice necessitates a discussion on the host origin and distribution in more than one river system, particularly referring to host specificity for Chonopeltis species., Graphical abstract Image 1, Highlights • First COI sequence for genus Chonopeltis. • First phylogenetic analysis of Branchiurans using 18 S rRNA. • New host and locality record for Chonopeltis lisikili. • First illustrations of the majority of C. lisikili life stages, in fact for any of the known Chonopeltis species.

In this paper, Argulus japonicas Thiele, 1900, the Japanese fish louse is reported for the first time for the fauna of Montenegro.

Modern crustaceans are extremely diverse, not only in their morphologies, but also in their life styles. It is therefore not surprising that parasitism evolved in various lineages of Eucrustacea independently, in groups such as amphipodan, isopodan and copepodan crustaceans, but also barnacles and fish lice. Parasitic crustaceans have become specialized to many different host species and show a wide variety of attachment and feeding specializations. Among the parasitic crustaceans, different groups are especially interesting to study for reconstructing the evolution of parasitism within this group. This chapter summarizes the modern aspects, evolutionary history and fossil record of parasitic crustacean groups. By reviewing the parasitic crustaceans with emphasis on their fossil record, this chapter aims to improve our understanding of parasitism in general.

Coastal cutthroat trout [Oncorhynchus clarkii clarkii (Richardson, 1836)] from the marine waters of Puget Sound, WA, was documented as a new host for the ectoparasite Argulus pugettensis (Dana, 1852). The prevalence of A. pugettensis was 66% (49 of 74) on cutthroat trout and 0% (0 of 55) on coho salmon [O. kisutch (Walbaum, 1792)] collected during the winter of 2017/2018. Infestations occurred most frequently on the dorsal surface, with intensities ranging from 1 to 26 argulids per fish (mean intensity 3.94 ± 4.93 S.D.). In contrast, the prevalence of the common salmon louse [Lepeophtheirus salmonis (Kroyer, 1837)] was 72% for cutthroat trout and 31% for coho salmon. Relative to other native salmonids, little is known regarding the status, ecology and threats for coastal cutthroat trout. New information reported here is a first step in understanding the relationship between this wild, native trout and infestations by parasitic sea lice and should be followed by future studies aimed to identify population level consequences.

In this work, we document for the first time four species of Ichthyostraca in Mexico, one Branchiura: Argulus foliaceus (fish parasite), and three Pentastomida: Porocephalus clavatus (reptile parasite), Raillietiella hebitihamata (reptile parasite) and Raillietiella orientalis (frog parasite). In addition, a total of 11 new host records and 16 new localities are presented for Ichthyostraca in Mexico. Based on the compilation of published information and on specimens deposited in scientific collections, the first checklist of Ichthyostraca from North America (Canada, United States of America and Mexico) is compiled. To March 2019, records of Ichthyostraca from North America include 64 species and 8 undetermined taxa, parasitizing 293 host species (64 of them identified only to a supra-specific level) in 77 provinces and states (8 from Canada, 47 from the USA, and 22 from Mexico). The subclass Branchiura is represented by 1 order, 1 family, 1 genus, 35 species and 1 undetermined taxa; the subclass Pentastomida includes records of 4 orders, 9 families, 14 genera, 29 species and 7 undetermined taxa. Ten species reported in this work are thought to be introduced into North America with only a few records of them parasitizing native hosts. This checklist summarizes the available records of this class of crustaceans in North America and represents a base line for future studies.

Argulus indicus (Crustacea: Branchiura), or the fish louse, is an external parasite in Phylum Arthropoda found on the skin, fin or gills of freshwater fish species. It is very flat with an oval or rounded carapace, two compound eyes, sucking mouthparts with a piercing stylet, and two suction cups it uses to attach to its host. Clinical signs in infected fishes include scratching on aquarium walls, erratic swimming and poor growth. It causes pathological changes due to direct tissue damage and secondary infections. In the present study, red tilapia (Oreochromis niloticus x Oreochromis mossambicus), with symptoms such as abnormal swimming or scratches on their skin, were collected from a cage culture at Klong Rapee-Phat, Nong-Seau District, Pathum-Thani Province in Thailand. The parasites collected from the skin and fins of infected red tilapia were identified as Argulus indicus. This is the first report of infection with A. indicus of red tilapia (O.niloticus x O. mossambicus) in Thailand.

A total of 30 specimens of fish cobia Rachycentron canadum (Total Length = 45–120 cm, Weight = 3.0–25 kg) were stocked at the density of 1 kg/m3 in the polythene lined earthen pond. After 3 months of stocking, fish cobia was found with infection of ectoparasites. Then fishes were sampled at fortnight interval to find the percentage distribution of ectoparasites in different parts of the body for a year and also any pathological symptoms. Identification of the parasite was made through light and electron microscopies. The parasite was identified as Argulus quadristriatus Devaraj and Ameer Hamsa, 1977 (Crustacea: Branchiura: Argulidae) commonly called as fish lice. The maximum distribution of pathogenic argulid was observed on the head and operculum of cobia and was found high in summer months from April to June. Pathological symptoms were observed on cobia as erratic swimming, rubbing against substrate in the pond and lesions of epithelial tissues on the infected regions. It must be due to continuous rupturing and feeding of argulids on the skin of cobia using its powerful antennae. Scanning electron micrographs revealed some important morphological features of A. quadristriatus. This is a first report of A. quadristriatus infection on cobia reared in a land-based pond ecosystem.

The female reproductive system has been described for Dolops ranarum (Stuhlman, 1891) and various Argulus spp. but, there is no description of the reproductive system for Dipteropeltis spp. Calman, 1912 or Chonopeltis spp. Thiele, 1900. This paper describes the female reproductive system and egg laying behaviour of Chonopeltisaustralis Boxshall, 1976 using histology, light microscopy, scanning electron microscopy and observations. The histological study of six specimens showed that the organ structure is similar to that of Argulus spp. and D. ranarum. The oocytes therefore develop in the gonocoel, are ovulated into the lumen of the ovary which is continuous with the functional oviduct and eventually the gonopore. Females of C. australis deposit eggs on the surrounding substrate while the fish is at rest, without leaving the host, thereby mitigating the risk of not locating a host again.

The spotted tiger shovelnose catfish Pseudoplatystoma punctifer (Castelnau, 1855), has a high commercial value and there is considerable interest for its culture in Peru and outside of its original distribution area. Infestations by branchiurans may cause damage to stock resulting in economic losses on fish and in fish farming. Thus, the present study set out to detail the infection on farmed stock at one Peruvian site. Twenty fish were collected from a fish pond located in Iquitos, Peru in April 2018. All fish were parasitized by Dolops discoidalis Bouvier, 1899 , with an intensity of 92 (1–13 parasites fish-1), with a mean abundance of 4.6 ± 3.3 parasites fish-1. There were correlations between fish standard length, weight and parasite number (rs = 0.51, p = .02; rs = 0.64, p = .002) respectively. The relative condition factor of the hosts was not affected by the parasitism. The high prevalence of argulids detected warns the possibility of an epizootic, under inadequate management conditions or drastic changes in physical and chemical water parameters, placing the production of this fish species at risk.

The present study recorded the parasite Argulus japonicus (Crustacea: Branchiura) as the first discovery in Nepal. The description was based on using 11 males (4.12 mm average TL) and 5 females (4.18 mm average TL) of Argulus japonicus which were collected from Godawari fish farm, Lalitpur. Biological behavior of one summer old common carp (Cyprinus carpio) infected with Argulus japonicuswere sluggish movement, jumping and poor growth grown in earthen pond in winter at water temperature 15.5 ºC and pH 7.4. Heavily infected fishes showed brown-grey to reddish points throughout their body surface, especially on the caudal fins and on the body portion. Prevalence rate of this parasite was 80% in infected common carp fish with an average weight 261.80±85.12 g and length 22.9±4.9 cm. Argulus mean intensity count was averaged 10.2 per infected fish with relatively high infestation in body surface (2.8±3.9) followed by caudal fin (1.8±4.5) and dorsal fin (1.1±1.5). Prevalence rate of this parasite in treated common carp reduced by 95% and Argulids assembled in several regions of the fish was in average 0.1/treated fish by feeding Duroclean treated feed. Duroclean, an aquaculture drug was found effective to control this parasite. The effective dose of the drug was 0.3 g per kg fish feed and fed for 3 days consecutively with one day off and then again for 2 days.

The ayu Plecoglossus altivelis altivelis, a popular fishery resource in Japan, harbors a branchiuran parasite Argulus coregoni in wild rivers. This parasite has so far been investigated in its direct and indirect pathogenicity to freshwater salmonids, which are considered as the preferred hosts, but potential impacts on other host fishes including ayu have not been emphasized. We here evaluate the negative effect of this parasite on ayu, based on experimental infections using parasite specimens obtained from the same host species in the Oouchiyama River of Mie Prefecture, Japan. After 16 days from the release of A. coregoni (n = 14) into a tank rearing 68 host ayus, 9 ayus were dead and 16 developed abnormalities (i.e. erosion, ulcerative lesion, appearance of cloudy areas or haemorrhages on the body surface and basal-part erythema of the pectoral fins), whereas no abnormality was found in the control tank which also reared 68 host individuals. In addition, the infected group exhibited a decrease in body condition compared to the control group. The same pathogenicities were also recorded in an additional replication. These findings suggest that A. coregoni is responsible for biological and economic losses in the stock enhancement. Infection ecology for ayu, therefore, deserves further attention.

Chonopeltis Thiele, 1900 presently comprises 14 species, it is endemic to Africa and its species show a high degree of host-specificity towards fish families and in some cases, individual fish species. Chonopeltis meridionalis Fryer, 1964 was originally described from Labeo rosae Steindachner collected in the River Nuanetsi in Rhodesia, now Zimbabwe, Limpopo River System. At the time of description C. meridionalis was the most southerly species of the genus. Chonopeltis victori Avenant-Oldewage, 1991 was described from the River Olifants, Mpumalanga, South Africa, which also forms part of the Limpopo River System. The host fish was Labeo rosae and Labeobarbus marequensis (A. Smith), whilst C. koki Van As, 1992 was described from Labeo cylindricus Peters, collected in the River Zambezi, Eastern Caprivi, Namibia. During surveys conducted in 2012, additional material of a species of Chonopeltis was collected from Labeo rosae in the River Olifants. Upon closer examination, the new material was identified as C. meridionalis. Further investigation revealed that C. victori and C. koki share a number of characteristics with C. meridionalis. This paper provides the first scanning electron microscopy of C. meridionalis, includes additional information on fully-mature as well as sub-adult males and females. Finally, it was concluded that C. victori and C. koki are junior synonyms of C. meridionalis.

An argulid branchiuran, Argulus quadristriatus Devaraj and Ameer Hamsa, 1977 , is reported on the basis of specimens of both sexes isolated from two species of goatfish [Upeneus tragula Richardson, 1846 and Parupeneus ciliatus (Lace-pede, 1802) (Perciformes: Mullidae)] and the goby Favonigobius reichei (Bleeker, 1854) (Perciformes: Gobiidae) collected in Kagoshima Bay and off both the east and west coasts of Okinawa-jima island, southern Japan. The branchiuran is easily distinguished from its nine previously recorded congeners in Japanese waters by the presence of one posterior spine on the antennule and scales ornamenting the basal half of the mouthtube. These are the first records of this branchiuran from the North Pacific Ocean including Japanese waters, and the three fish species mentioned above are new hosts for it.

Background It is hypothesised that being a blood-feeding ectoparasite, Argulus foliaceus (Linnaeus, 1758), uses similar mechanisms for digestion and host immune evasion to those used by other haematophagous ecdysozoa, including caligid copepods (e.g. sea louse). We recently described and characterised glands associated with the feeding appendages of A. foliaceus using histological techniques. The work described in the present study is the first undertaken with the objective of identifying and partially characterising the components secreted from these glands using a proteomic approach. Methods Argulus foliaceus parasites were sampled from the skin of rainbow trout (Oncorhynchus mykiss), from Loch Fad on the Isle of Bute, Scotland, UK. The proteins from A. foliaceus secretory/excretory products (SEPs) were collected from the supernatant of artificial freshwater conditioned with active adult parasites (n = 5–9 per ml; n = 560 total). Proteins within the SEPs were identified and characterised using LC-ESI-MS/MS analysis. Data are available via ProteomeXchange with identifier PXD016226. Results Data mining of a protein database translated from an A. foliaceus dataset using ProteinScape allowed identification of 27 predicted protein sequences from the A. foliaceus SEPs, each protein matching the criteria of 2 peptides with at least 4 contiguous amino acids. Nine proteins had no matching sequence through OmicsBox (Blast2GO) analysis searches suggesting that Argulus spp. may additionally have unique proteins present in their SEPs. SignalP 5.0 software, identified 13 proteins with a signal sequence suggestive of signal peptides and supportive of secreted proteins being identified. Notably, the functional characteristics of identified A. foliaceus proteins/domains have also been described from the salivary glands and saliva of other blood-feeding arthropods such as ticks. Identified proteins included: transporters, peroxidases, metalloproteases, proteases and serine protease inhibitors which are known to play roles in parasite immune evasion/induction (e.g. astacin), immunomodulation (e.g. serpin) and digestion (e.g. trypsin). Conclusions To our knowledge, the present study represents the first proteomic analysis undertaken for SEPs from any branchiuran fish louse. Here we reveal possible functional roles of A. foliaceus SEPs in digestion and immunomodulation, with a number of protein families shared with other haematophagous ectoparasites. A number of apparently unique secreted proteins were identified compared to other haematophagous ecdysozoa.

Crustaceans have independently adopted a parasitic mode of life on numerous occasions, and this chapter reviews the classification and species richness of each of the parasitic clades, which lie within two major pancrustacean lineages, the Multicrustacea and the Oligostraca. Tabulated data are presented on the genera, species richness and host usage of the whale lice (Cyamidae); the generic and species richness of the families of hyperiidean amphipods; the generic and species richness and the host usage of the families and subfamilies of epicaridean isopods; the species richness, salinity regime and host taxon of cymothoid isopods; the generic and species richness and the host usage of the families of Ascothoracida and Rhizocephala; the species of Tantulocarida and their hosts; the generic and species richness and the host usage of the families and family-level groupings of cyclopoid and siphonostomatoid copepods; the species richness and salinity regimes of the genera of Branchiura; and the species richness and host usage of the genera of tongue worms (Pentastomida). Parasitic crustaceans use a total of 15 different phyla as hosts.

Parasitic crustaceans are globally considered to be some of the most successful and diverse parasites. They are ubiquitous in the aquatic environment and are known to occur on a wide range of vertebrate and invertebrate hosts. However, despite their common occurrence and large numbers, a book dedicated exclusively to these parasites has not been published. The book presented here provides detailed information on the major parasitic Crustacea groups, including those from Amphipoda, Ascothoracida, Branchiura, Cirripedia, Copepoda, Isopoda, Ostracoda, Pentastomida and Tantulocarida. Each chapter discusses the different aspects of the biology of these parasites, allowing for a better understanding of how the parasitic Crustacea function and for direct comparisons between different parasitic crustacean groups. In this book the authors review the history of discovery of the parasitic Crustacea; their biodiversity and taxonomy; their adaptations and types of crustacean symbiotic associations; their life cycle and life history strategies; their effects on their hosts; their role as vectors, hypersymbionts and hyperparasites and their molecular contribution (parasitic barnacles only), as well as their ecological significance. In addition to reviewing all of the relevant literature, new and unpublished data are included in all of the chapters. Altogether, this book highlights the morphological and ecological attributes that have made the parasitic Crustacea successful and aims to inspire and encourage current and future research into this ecological and economical important field of study.

Microsporidians, peritrich ciliates, udonellids, tantulocarids and parasitic isopods have been found associated with parasitic crustaceans, i.e. Branchiura, parasitic Copepoda and Isopoda, as well as Rhizocephala (parasitic Cirripedia). Information on the Microsporida found in parasitic Copepoda are scarce, whilst infestation in gregarines, myxosporidia, cestodes and trematodes has been reported. Information is provided from known records of hypersymbiont infestations, as well as some unpublished data collected of peritrichs (Epistylis and Vorticella) found on the fish parasites Dolops and Argulus (Branchiura), members of Lernaea and Opistolernaea (Copepoda: Lernaeidae) and Ergasilus (Copepoda: Ergasilidae). The genus Doropygus (Copepoda), found in the branchial chamber of redbait (Ascidiacea), also harbours peritrichs. These hypersymbionts take the association to the next level, as the ciliates themselves harbour zoochlorellae. Helminths of the family Udonellidae are found associated with caligids and sometimes branchiurans, which occur on the skin of marine fishes. Tantulocaridans (Hypertantulus siphonicola) have been reported from siphonostomatoid copepods. Cabiropidae (Cabirops) are hyperparasites found in the brood pouch of bopyrid hosts, and C. orbionei might be considered as biological control for bopyrids, which are found on penaeid shrimps. Four genera of the family Cryptoniscidae (Liriopsis, Cryptoniscus, Hemioniscus and Danalia) and one genus of the family Cabiropidae (Perezina) are parasites of rhizocephalans that are parasitic on decapod hosts.

Species of Argulus (Branchiura Thorell, 1864) are common ectoparasites of freshwater, estuarine, and marine fishes. Argulid identification and taxonomy is often confusing because many species are reported to parasitize multiple host species, have similar morphological characters, and come from various salinity regimes. Gulf sturgeon is an anadromous fish natal to drainages in the north-central Gulf of Mexico, and as with many endangered species, has a poorly documented parasite community. During Gulf sturgeon tagging and monitoring studies (2016&ndash, 2019) in the Pascagoula River, MS, USA, species of Argulus were collected from Gulf sturgeon as well as other incidentally captured fishes. Argulus flavescens Wilson, 1916 was found on Gulf sturgeon and flathead catfish, Argulus americanus Wilson, 1902 on bowfin, and Argulus bicolor Bere, 1936 on Atlantic stingray. We provide morphological details and measurements for these species as well as the first confirmed 28S rDNA molecular data. Argulus flavescens was more abundant and prevalent on larger Gulf sturgeon and on sturgeon captured in freshwater rather than estuarine habitats. Our results indicate that A. flacescens may not tolerate estuarine salinities and that the anadromous life-history pattern of Gulf sturgeon could help rid them of A. flavescens when they emigrate from their riverine habitats.

A histological study of the pre-oral spine and associated structures in Argulus japonicus reveals that two exceptionally long and slender muscles casuse retraction of the spine into the spinal sheath. Originating from the body wall mid-dorsally the two muscles proceed through the nerve ring and the blood-filled lumen of the spinal sheath before being inserted on a bolster of tissue constituting the base of the spine. Movement of the spinal sheath is affected by two muscles originating from a common apodeme in the dorsal body wall, just posterior to the nauplius eye, and inserted on the lateral walls of the base of the spinal sheath. Two ducts, each leading from a glandular complex in the lateral parts of the carapace, proceed rostrally through the haemocoelic spaces. After passing the tritocerebrum laterally they accompany the retractor muscles of the spine on their course to the base of the spine. Passing through the bolster of tissue at the base of the spine the two ducts run all the way up to the tip of the spine where they open separately. The glandula praeboscoidalis is not associated with the pre-oral spine since its duct runs posteriorly in the wall of the proboscis. The labial spines are associated with giant glandular cells located beneath the optic tracts. © 1992 Wiley-Liss, Inc.

Hemocyanin transports oxygen in the hemolymph of many arthropod species. Within the crustaceans, this copper-containing protein was thought to be restricted to Malacostraca, while other crustacean classes were assumed to employ hemoglobin or lack any respiratory protein. Only recently it has become evident that hemocyanins also occur in Remipedia and Ostracoda. Here we report for the first time the identification and characterisation of hemocyanin in the fish louse Argulus, which belongs to the class of Branchiura. This finding indicates that hemocyanin was the principal oxygen carrier in the stem lineage of the pancrustaceans, but has been lost independently multiple times in crustacean taxa. We obtained the full-length cDNA sequences of two hemocyanin subunits of Argulus foliaceus by a combination of RT-PCR, RACE and Illumina sequencing of the transcriptome. In addition, one full-length and one partial cDNA sequence were derived from the transcriptome data of Argulus siamensis. Western blot analysis confirmed the presence of at least two hemocyanin subunits in A. foliaceus, which are expressed at the mRNA level at a 1:3.5 ratio. The addition to the branchiuran hemocyanin subunits to a multiple sequence alignment of arthropod, hemocyanins improved the phylogenetic resolution within the pancrustacean hemocyanins. Malacostracan, ostracod and branchiuran hemocyanins are distinct from the hexapod and remipede hemocyanins, reinforcing the hypothesis of a close relationship of Remipedia and Hexapoda. Notably, the ostracod hemocyanins are paraphyletic with respect to the branchiuran hemocyanins, indicating ancient divergence and differential loss of distinct subunit types.

The present investigation was carried out to underscore the developmental events of a crustacean ectoparasite of fish, Argulus bengalensis. Serial histological sections of the embryo were made at lateral, sagittal and longitudinal planes to explain its cleavage, gastrulation and axis specification. The centrolecithal egg of A. bengalensis underwent meroblastic superficial cleavage. The cleavage initiated at the future dorsal side of the egg within 5 h to 5 h and 30 min of incubation. Consequently, a small mass of energids appeared superficially at the future dorsal side within 6 h. Later, energids were found at the future ventral and lateral sides. A syncytial blastoderm was formed around the centrally placed yolk material which was transformed into a cellular blastoderm within 30 h of incubation. In the blastoderm, two cell masses were formed at the dorsal and ventral part which initially extended towards each other and later spread out though future anterior-posterior direction. The pressure exerted by the cell flow displaced the entire yolk material at the future postero-ventral side. At the time of egg laying, a prototype of the embryonic axes is determined. The substratum side of the egg formed the dorsal part, whilst the side facing water turned to the ventral part. The broader end of the egg formed the anterior side and the narrow end formed the posterior side of the embryo. The anterior-posterior axis formation was initiated within 72 to 96 h of incubation when the blastodermal cells displaced the yolk material at the future posterior end. Within 120 h of incubation, the germ layers of the embryo were determined. The study reveals that the cleavage pattern of A. bengalensis shows close similarities with that of the Malacostraca amongst the crustaceans and dipteran and hymenopteran amongst the insects.

The male reproductive system of the fish ectoparasite Argulus bengalensis was reconstructed with serial histological sections through longitudinal and transverse planes and the description was re-evaluated after the discovery of spermatophore. The study revealed that the testis of A. bengalensis consists of two lobes, each comprised the two enclaves. The outer enclaves from both lobes are connected proximally with an isthmus. The inner enclave is covered with two layers of chromatophores which are presumably involved in androgenic hormone production. At the proximal end of the inner enclaves a pair of vasa efferentia originates and ascends into thorax where it leads into vesicula seminalis. Like Dolops ranarum, a pair of spermatophoric glands is found in the thorax just behind the second maxilla. Glandular cells of the spermatophoric glands are columnar with a large nucleus at their basal side. A pair of spermatophoric canals carries the secretion of the glands into the vesicula seminalis through vasa efferentia. Spermatophores are delivered to the female through a median vas deference originating from the vesicula seminalis. In addition to the spermatophoric glands, a pair of accessory glands is located in the coxa of the fourth thoracic legs. At the region dorsal to the isthmus both the spermatophoric canal and accessory gland ducts unite with the vas efferens of the respective side. The secretion of the accessory gland presumably contributes to semen composition of the parasite. J. Morphol. 276:540–549, 2015. © 2015 Wiley Periodicals, Inc.

Feeding strategies that reduce feed and promote compensatory growth could be an interesting tool to reduce costs in the fish production. However, fish health must be monitored to evaluate if their physiological response to adverse conditions, such as parasite infection, does not become compromised. A 12-wk growth trial was conducted to determine the physiological responses of pacu, Piaractus mesopotamicus, that were subjected to different fasting/refeeding cycles and infected with the Dolops carvalhoi. The schemes were: (i) control group fish (FD), (ii) food-restricted and controlled refeeding group (FR/Rc), and (iii) food-restricted and refeeding to satiation group (FR/Rs). After 84 d, the fish were exposed to D. carvalhoi for 30 h. The fish subjected to food restriction did not exhibit compensatory growth. Cortisol levels decreased in all groups within 30 h after infection. Glucose levels increased 6 h after the D. carvalhoi in the FR/Rs and 30 h after infection in the FD. In all of the fish groups, the hematocrit values were reduced after infection, and it was associated with a reduction in the mean corpuscular volume and erythrocytes. At 30 h after infection, the number of erythroblasts increased. The use of the feeding schemes does not indicate a failure of the pacu physiological responses.

Efficacy of treatment with some plant parts containing ingredients viz. rotenone, azadirachtin, and nicotine for control of a piscine ectoparasite Argulus bengalensis has been tested in laboratory experiments. Among those plant preparations, tobacco leaf dust (TLD) containing nicotine is found potentially active against the adult parasitic morphs at a lethal concentration of 8 ppm which is sublethal and tolerable to the host fish. However, nicotine is not effective on the embryonic life stages of the parasite and thus the gene pool is retained in the form of egg investment. Embryonic development and subsequent hatching of the eggs occurs normally in the post treatment period which results in recurrence of parasitaemia (F1 generation) within 12 to 16 days in summer and 15 to 18 days in winter in a temperature dependant manner. Considering maturation of F1 generation and subsequent investment of their first clutch of eggs at the age of 21 days onwards, one vulnerable time window of 17 to 19 days for summer experiment and another of 19 to 21 days for winter experiment have been identified. Since the time windows are brief and exist only for three days and those windows overlap at day 19, the day 19 has been targeted for application of a second phase of treatment in both seasons. The study recommends a new approach of biphasic treatment for complete eradication of A. bengalensis infestation.

The Life table features and the fecundity schedule of the fish louse Argulus bengalensis (Branchiura: Argulidae) were estimated under laboratory conditions using Cirrhinus mrigala as the model host. The cohort-based Life table revealed that survival of A. bengalensis declines as a function of age. Life expectancy was observed to be 34 days for a newly emerged adult. The mean number of eggs produced per egg strip was 86 (±8.89 S.E.). The sex ratio 2:1 was biased towards males. The net reproductive rate (R0) varied between 50 and 487 while the cohort generation time (Tc) ranged between 24 and 26 days. The intrinsic rate of increase (r) was 0.14–0.23, while the finite rate of increase (λ) remained between 1.16 and 1.28. The Life table features and the fecundity schedule of A. bengalensis are comparable with congenerics of temperate regions. Early reproduction (between 21 and 23 days) and an extended postreproductive phase (47 days) of females are characteristic of A. bengalensis and a reflection for survival...

In this paper the major description, epidemiology, pathogenesis and clinical sign, diagnosis, treatment and control of parasitic crustaceans in fish has been reviewed. The major crustaceans parasites commonly encountered in cultured and wild fish are: copepods (ergasilidea and lernaeidae), branchiura (argulidae) and isopods). Members of the branchiura and isopod are relatively large and both sexes are parasitic, while copepods are the most common crustacean parasites are generally small to microscopic with both free-living and parasitic stages in their life cycle. These parasitic crustaceans are numerous and have worldwide distribution in fresh, brackish and salt water. Most of them can be seen with naked eyes as they attach to the gills, bodies and fins of the host. They are increasingly serious problem in cultured fish and can infect wild population. Usually they cause only minor harm to their hosts when present in small numbers. However, in case of heavy infections severe damage to skin, muscles, and gills tissue accompanied with secondary infections, and resulting in decreased production. Good health management and good environment management are crucial in avoiding occurrence of crustacean parasites.

The genus Argulus is economically one of the most important taxa of crustacean ectoparasites in freshwater aquaculture systems throughout the world. This study investigates the occurrence and effect of a mixed infestation of two species of Argulus, Argulus japonicus Thiele, 1900 and Argulus siamensis Wilson, 1926, in a carp culture farm in Mandi, Himachal Pradesh, India. In this study the economic loss due to argulosis was estimated to be 67 102.00 INR (US$ 1428)/ha per year, taking into account factors like mortality, reduced growth rate, and costs associated with drug application. The parasite population of the farm under study was dominated by A. japonicus, which constituted 93.5% of the population, the rest being A. siamensis. The dominance of A. japonicus can be explained by a comparison of the invasiveness of both species through determination of their off-host survival period, fecundity, and infestation pattern. A. japonicus was found to be better adapted to resist starvation, as the maximum off-host survival period for A. japonicus was 6 days, compared to 4 days in A. siamensis at 28°C. The average clutch size of A. japonicus was experimentally found to be 187 eggs, versus 120 for A. siamensis. An experimental mixed infestation of both species was established on Labeo rohita (Hamilton, 1822) to assess their infestation patterns, which proved A. japonicus to be more virulent than A. siamensis. The wide distribution of A. japonicus in comparison to A. siamensis may thus be attributed to its relatively prolonged off-host survival period, higher fecundity, and stronger virulence.

The genus Dolops is one of only four genera in Branchiura, and as most other members of the group it is also ectoparasitic on freshwater fish. The large majority of investigations of the genus concern the single species of Dolops found in southern Africa, D. ranarum, although most of the remaining species are found in South America. In this paper, we present the first morphological description of the larva of D. carvalhoi using light- and scanning electron microscopy. This is the first detailed account of the larvae of any non-African species of Dolops, and our comparison of the larvae of D. carvalhoi and D. ranarum based on literature data show them to be surprisingly alike. The general implications of these findings are discussed in a phylogenetic context, with special emphasis on the different larval types found in the other genera of Branchiura.

17. Branchiura sowerbyi Beddard, 1892 Branchiura sowerbyi Beddard. Chen 1940: 90 ���96, 1959: 19; Liang 1962: 22, 1979: 276���277; Brinkhurst, Qi & Liang 1990: 912; Wang 2002: 132 ��� 131; Cui 2008: 107 ���108. Material. Yarlung Zangbu River: ST 5, 3 spms. Niyang River: ST 30, 2 spms; ST 32, 5 spms. Lake Yamzhao Yumco: ST 52, 4 spms. Lalu Wetland: ST 59, 5 spms; ST 60, 5 spms. Remarks. Cosmopolitan species. First record from Tibet., Published as part of Cui, Yongde, He, Xuebao, Peng, Yu & Wang, Hongzhu, 2015, Records of Naididae and Lumbriculidae (Clitellata) from Tibet, China, with description of a new species of Nais, pp. 513-530 in Zootaxa 3956 (4) on pages 525-526, DOI: 10.11646/zootaxa.3956.4.4, http://zenodo.org/record/240764, {"references":["Liang, Y. L. (1962) On some naids and tubificids from north-eastern China. Acta Hydrobiologica Sinica, 2, 14 - 26. [in Chinese with English abstract]","Brinkhurst, R. O., Qi, S. & Liang, Y. L. (1990) The aquatic Oligochaeta from the People's Republic of China. Canadian Journal of Zoology, 68, 901 - 916. http: // dx. doi. org / 10.1139 / z 90 - 131","Wang, H. Z. (2002) Studies on taxonomy, distribution and ecology of microdrile oligochaetes of China, with description of two new species from the vicinity of the Great Wall Station of China, Antarctica. Higher Education Press, Beijing, 228 pp. [in Chinese with English abstract]","Cui, Y. D. (2008) Studies on Oligochaeta (Annelida) of Lakes in Yunnan, Southwest China. PhD Thesis, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 200 pp. [in Chinese with English abstract]"]}

Eighteen female specimens of Argulus vittatus (Rafinesque-Smaltz, 1814) were recently collected from the Algerian coast. As until now this species was poorly described, this contribution redescribes this species with more precise drawings on the general morphology and appendages, using this fresh material. For the first time, two new hosts are identified. Host specificity and some ecological data are also reported.

Although parasite habitat preference is well studied, it is rarely rigorously evaluated statistically because of many zero intensities. Attachment-site preference and intensities of 2 macroectoparasite species ( Caligus elongatus and Calliobdella vivida ) of Atlantic sturgeon, Acipenser oxyrinchus Mitchill, in Minas Basin, Bay of Fundy, Canada, were characterized with the use of zero-inflated negative binomial statistical models that included a fork-length offset to control for body size. Three other parasites were encountered, sometimes in high numbers on various body sites, but too few counts overall prevented construction of meaningful statistical models. Of 26 sturgeons, prevalence of (1) C. elongatus (Copepoda) was 85%, mainly on caudal fins and nonfin body sites; (2) C. vivida (Hirudinea) was 81%, mainly on the pelvic and pectoral fins, and dorsal and ventral-lateral body sites; (3) Dichelesthium oblongum (Copepoda) was 31% within the gills or burrowed into the musculature at the base of fins; (4) Argulus stizostethii (Crustacea: Branchiura) was 8%; and (5) Nitzschia sturionis (Monogenea) was 12%. Only D. oblongum was associated with visible damage, mainly as lesions on gills and soft tissues. Characterizing parasite prevalences within the Bay of Fundy is important because some parasites affect fish health and population biology.

This study reports on the anatomy and structural details of the feeding apparatus and associated glands in a tropical fish ectoparasite, Argulus siamensis Wilson, 1926. The results reveal that anatomically the feeding apparatus of the species consists of a proximal buccal proboscis and a retractile pre-oral spine surrounded by a sheath. The mouth is located at the terminal end of the buccal proboscis. Two types of glands, the spinal gland and the proboscis gland, are associated with the feeding apparatus. The sac-like spinal gland, consisting of four polygonal cells, is located at the base of the spine. It is continuous with the median duct of the spine but does not show any connection with the buccal cavity. Numerous secretory vesicles are present in the cytoplasm. The proboscis glands are located parallel to the spinal sheath, one on both sides, and open directly into the buccal proboscis. Each proboscis gland houses two giant cells, the cytoplasm of which is largely occupied by secretory vesicles. The present study, aimed at understanding the functional relation of the glandular secretions with the feeding mechanism, revealed that the secretion of the spinal gland is neither cytotoxic nor haemorrhagic, but may have anaesthetic or vasodilatory activity. Indications are available to show that the secretion of the proboscis gland is anticoagulant in nature.

[The argulids are an economically important group of crustacean ectoparasites known to be problematic in fish farming operations from both temperate and tropical regions. Argulus japonicus was first described from Japanese fish but is now well established in many parts of the world including Europe. To aid the development of effective chemotheraputants and/or vaccines against these parasites it is essential to know exactly what these animals ingest when feeding upon their fish hosts. From past morphological studies authors have shown that these parasites use a proboscis-like mouth tube for feeding, however, until now there has been much speculation amongst authors over the diet of these animals. Live observations, histology, as well as scanning and transmission electron microscopy were used to examine the feeding apparatus and gut contents of individual larval and adult lice before and after feeding on juvenile common carp, Cyprinus carpio. Red coloration of the parasites gut after feeding was obvious, suggesting ingestion of red blood cells by the adult lice. Sections of the adult lice used for histology and TEM revealed red blood cells from the fish host within the parasites gut. Larval lice were found not to feed on blood cells because of their mouth part morphology and the lack of blood cells in their intestines. Haemorrhagic responses of the hosts skin by infection of adult lice was observed between 24 and 48 hrs post infection. All techniques provided evidence that the adult parasites are indeed obligate blood feeders. Les argulides sont un groupe de crustaces ectoparasites, economiquement importants, connus pour poser des problemes en aquaculture a la fois dans les regions temperees et tropicales. Argulus japonicus a ete decrit pour la premiere fois sur des poissons japonais, mais est maintenant bien etabli dans de nombreuses parties du monde Europe comprise. Pour aider le developpement d'une chimiotherapie effective et/ou de vaccins contre ces parasites, il est essentiel de connaitre exactement ce que ces animaux ingerent lorsqu'ils se nourrissent sur le poisson hote. Des etudes morphologiques anterieures ont montre que ces parasites utilisent un tube buccal en sorte de proboscis pour s'alimenter. Cependant, jusqu'a present, il y a eu de nombreuses speculations entre les auteurs a propos de leur regime alimentaire. Des observations sur le vivant, de l'histologie ainsi que de la microscopie electronique par transmission et balayage ont ete utilisees pour examiner l'appareil buccal et le contenu stomacal des individus larvaires et adultes avant et apres un repas sur des juveniles de carpe commune Cyprinus carpio. Une coloration rouge du tube digestif des parasites apres alimentation a ete observee, suggerant une ingestion de globules rouges par le pou adulte. L'observation histologique et par MET de coupes de poux adultes montrent la presence de globules rouges provenant du poisson hote dans le tube digestif du parasite. Les poux larvaires ne se nourrissent pas de cellules sanguines de part leur morphologie buccale et de l'absence de cellules sanguines dans leur intestin. Des reponses hemorragiques au niveau de la peau de l'hote infecte par des poux adultes ont ete observees 24 a 48 h apres l'infection. Toutes les techniques demontrent que les parasites adultes sont des hematophages obligatoires., The argulids are an economically important group of crustacean ectoparasites known to be problematic in fish farming operations from both temperate and tropical regions. Argulus japonicus was first described from Japanese fish but is now well established in many parts of the world including Europe. To aid the development of effective chemotheraputants and/or vaccines against these parasites it is essential to know exactly what these animals ingest when feeding upon their fish hosts. From past morphological studies authors have shown that these parasites use a proboscis-like mouth tube for feeding, however, until now there has been much speculation amongst authors over the diet of these animals. Live observations, histology, as well as scanning and transmission electron microscopy were used to examine the feeding apparatus and gut contents of individual larval and adult lice before and after feeding on juvenile common carp, Cyprinus carpio. Red coloration of the parasites gut after feeding was obvious, suggesting ingestion of red blood cells by the adult lice. Sections of the adult lice used for histology and TEM revealed red blood cells from the fish host within the parasites gut. Larval lice were found not to feed on blood cells because of their mouth part morphology and the lack of blood cells in their intestines. Haemorrhagic responses of the hosts skin by infection of adult lice was observed between 24 and 48 hrs post infection. All techniques provided evidence that the adult parasites are indeed obligate blood feeders. Les argulides sont un groupe de crustaces ectoparasites, economiquement importants, connus pour poser des problemes en aquaculture a la fois dans les regions temperees et tropicales. Argulus japonicus a ete decrit pour la premiere fois sur des poissons japonais, mais est maintenant bien etabli dans de nombreuses parties du monde Europe comprise. Pour aider le developpement d'une chimiotherapie effective et/ou de vaccins contre ces parasites, il est essentiel de connaitre exactement ce que ces animaux ingerent lorsqu'ils se nourrissent sur le poisson hote. Des etudes morphologiques anterieures ont montre que ces parasites utilisent un tube buccal en sorte de proboscis pour s'alimenter. Cependant, jusqu'a present, il y a eu de nombreuses speculations entre les auteurs a propos de leur regime alimentaire. Des observations sur le vivant, de l'histologie ainsi que de la microscopie electronique par transmission et balayage ont ete utilisees pour examiner l'appareil buccal et le contenu stomacal des individus larvaires et adultes avant et apres un repas sur des juveniles de carpe commune Cyprinus carpio. Une coloration rouge du tube digestif des parasites apres alimentation a ete observee, suggerant une ingestion de globules rouges par le pou adulte. L'observation histologique et par MET de coupes de poux adultes montrent la presence de globules rouges provenant du poisson hote dans le tube digestif du parasite. Les poux larvaires ne se nourrissent pas de cellules sanguines de part leur morphologie buccale et de l'absence de cellules sanguines dans leur intestin. Des reponses hemorragiques au niveau de la peau de l'hote infecte par des poux adultes ont ete observees 24 a 48 h apres l'infection. Toutes les techniques demontrent que les parasites adultes sont des hematophages obligatoires.]

The process of sperm transfer is somewhat enigmatic in Argulus, even though copulation has been witnessed. A breeding colony of Argulus japonicus was kept under laboratory conditions in order to study reproduction in the species. Pairs in copula were removed and studied with histology and scanning electron microscopy to describe the mechanism of sperm transfer. Sections of copulating pairs revealed sperm on the accessory copulatory structures of the male's swimming legs; and scanning electron microscopy showed that sperm transfer occurs in three phases which can be differentiated to 10 different stages. Sperm transfer occurs via a spermatophore which is extruded from the genital aperture of the male and is then transferred to the socket on the third pair of legs of the male, before being transferred into the spermathecae of the female via the spermathecal spines. This is the first observation of a spermatophore in Argulus.

The Branchiura are fish ectoparasites which include the well-known and very commonly found genus Argulus. But the Branchiura also contains the monotypic genus Dipteropeltis, about which only very little is known. In this investigation of two female paratype specimens we describe for the first time the external morphology of Dipteropeltis based on Scanning Electron Microscopy. We show that Dipteropeltis has a pre-oral spine, unique suction disc support structures, an Argulus-like mouth cone and second maxillae with a combination of features seen in both Argulus and Chonopeltis. These data are compared with data from the three remaining branchiuran genera Dolops, Chonopeltis and Argulus and discussed in a phylogenetic context based on a recently proposed phylogeny of the group.

Parasitic crustaceans are responsible for severe disease outbreaks in finfish aquaculture. We provide the first report of five marine ectoparasitic crustacean species including Argulus diversicolor Byrnes, 1985 (Branchiura: Argulidae), Caligus bonito Wilson, 1905, C. longipedis Bassett-Smith, 1898, C. pelamydis Hewitt, 1963, and C. punctatus Shiino, 1955 (Copepoda: Caligidae) on wild arripid hosts, Arripis georgianus (Valenciennes, 1841), A. trutta (Forster, 1801) and A. truttaceus (Cuvier, 1829) (Perciformes: Arripidae) in southern Australian waters. Caligus pelamydis and C. punctatus are new Australian records. All five crustacean species exhibit low host-specificity and Argulus spp., C. longipedis, C. pelamydis and C. punctatus have been associated with mass mortalities in cultured fishes outside Australia. Given the propensity for arripids to aggregate at sea-cage aquaculture sites, awareness of these five parasitic crustacean species may allow health managers to identify and anticipate potential outbreaks on southern Australian fish farms.

The ectoparasitic are frequently found on various species of freshwater fishes. Species of genus Argulus are common and important parasites of freshwater fishes. These species are temporary parasites of fish and cannot survive without a host for long period. Many studies reported the transmission of Argulus species through freshwater fishes worldwide. The aim of this study is to review previous information on Argulus species, parasitic infections in freshwater fishes. The present study suggests that the biological controls can be used to reduce Argulus species among fish populations. In addition to prevent the spread of disease and parasites, this study recommends that fish should be examined for high risk parasites and other pathogens before their intended uses. Keywords: Argulus ; Parasites; Argulus foliaceus ; Diseases; Freshwater fishes

The genus Argulus (Crustacea: Branchiura), or fish louse, are common parasites of freshwater fish. This parasite have a direct life cycles and mature females leave the host and lay several hundred eggs on vegetation and various objects in the water. It caused pathological changes due to direct tissue damage and secondary infections. Besides the damage and stress caused by Argulus itself, one of the main worries for fish producers are the associated secondary infestations and infections that can result from infestation with this ecto-parasite. From 300 samples, only 20 (6.67 %) samples were infested with this parasite and 280 (93.33 %) not infested. In the present study, Argulus foliaceus was reported on goldfish and Koi which this was first recorded in Kerman, southeast of Iran. According to the presented study, it is clear that A. foliaceus can act as a potential risk factor for natural ecosystems and native fish population of Iran and other countries, that should be mentioned to prevent the burst of new parasitic fauna to Iran and different countries as well as stop direct economic losses caused by mortality derived from infestation with this ecto-parasite.

The ultrastructure of the cells of the digestive system of Argulus japonicus is described with the use of transmission electron microscopy. Specimens of Argulus japonicus were collected from the Vaal Dam in South Africa and fixed in Todd's fixative. The samples were post fixed in osmium tetroxide and embedded in resin. The anterior midgut is composed mostly of R cells while the enteral diverticula are composed mainly of R cells in the proximal diverticules and of F cells in the distal diverticula. The posterior midgut is composed of very large papilliform B cells and of R cells. The R cells in the anterior midgut probably absorb nutrients including lipids. The F cells are filled mostly with rough endoplasmic reticulum, suggesting enzyme synthesis, while the B cells portrayed endocytotic vesicles, indicating intracellular digestion of predigested food. The R cells of the posterior midgut are less active than cells present in the anterior midgut. E cells and peritrophic membrane were not observed.

The present paper summarized data on parasites of percid fishes (Actinopterygii: Percidae), such as pike-perch, European perch and ruffe from estuaries of the Polish coastal zone are listed, based on published records and long-term surveys carried out by the author. Parasites are listed alphabetically, separately for each host and for each parasite group with notes on their location on the host and geographical distribution (with references). A total of 41 species (taxa) of parasites were recorded on pike-perch Sander lucioperca (6 Ciliophora, 1 Myxozoa, 1 Monogenea, 11 Digenea, 4 Cestoda, 6 Nematoda, 5 Acanthocephala, 1 Mollusca, 1 Hirudinea, 4 Copepoda and 1 Branchiura). European perch, Perca fluviatilis, harboured 60 parasites (6 Ciliophora, 4 Myxozoa, 1 Monogenea, 18 Digenea, 9 Cestoda, 10 Nematoda, 5 Acanthocephala, 1 Mollusca, 1 Hirudinea, 4 Copepoda and 1 Branchiura). Ruffe Gymnocephalus cernuus featured 43 parasites (1 Microsporidia, 7 Ciliophora, 3 Myxozoa, 1 Monogenea, 13 Digenea, 5 Cestoda, 8 Nematoda, 2 Acanthocephala, 1 Mollusca and 2 Copepoda).

Killifish (Fundulus heteroclitus (L., 1766)) collected in the wild and kept in full-strength seawater were naturally parasitized by the ectoparasite Argulus funduli Kroyer, 1863, a copepod fish louse that creates inflamed skin le- sions on the opercular epithelium and host gills. We assessed the damage done by lesions by counting the density of mitochondria-rich cells by fluorescence microscopy and by measuring Cl - secretion rate electrophysiologically using con- trol (no lesions) and affected isolated opercular epithelia, often as paired left and right membranes from a single fish. Epi- thelia with lesions had a significantly reduced Cl - secretion rate, and in the lesions, the density of chloride cells was near zero. Contralateral membranes without lesions from infested fish had transport rates not significantly different from mem- branes taken from uninfected control animals, indicating no overcompensation on the contralateral membranes. Healthy control and infested animals were transferred to hypersaline conditions (twice seawater). Infested and control animals all survived transfer and had elevated plasma Na + and plasma osmolality. Infested animals failed to significantly elevate Im to the same level as healthy animals and there was a difference in hematocrit. Happily, the hypersaline challenge also re- sulted in detachment and death of adult A. funduli. We conclude that Argulus lesions impair salt transport in affected membranes but do not significantly affect survival on hypersaline challenge, and that hypersaline exposure is a successful treatment for A. funduli infestation in these strongly euryhaline teleosts. Resume´ : Des choquemorts (Fundulus heteroclitus (L., 1766)) recoltes en nature et gardes en eau de mer non diluee sont parasites naturellement par le copepode ectoparasite Argulus funduli Kroyer, 1863, un pou des poissons, qui cree des le´- sions cutanees inflammatoires sur l'epithelium operculaire et les branchies de l'hote. Nous avons evalueles dommages causes par ces lesions en comptant le nombre de cellules riches en mitochondries par microscopie a fluorescence; nous avons aussi mesurepar electrophysiologie la secretion de Cl - en utilisant des epitheliums operculaires isolest emoins (sans lesion) et affectes, souvent des membranes appariees droite et gauche provenant d'un meme poisson. Les epitheliums qui portent des lesions ont un taux significativement reduit de secretion de Cl - et la densitedes cellules a chlorures est presque nulle dans les lesions. Les membranes contralaterales non lesees des poissons infestes ont des taux de transport qui ne sont pas differents de ceux des membranes provenant des poissons temoins sains, ce qui indique qu'il ne se fait pas de surcom- pensation dans les membranes contralaterales. Nous avons transferedes animaux temoins sains et d'autres infestes dans des conditions hypersalines (deux fois l'eau de mer). Les animaux sains et infestes ont tous survecu a la transplantation et ils affichaient des concentrations accrues de Na + et une osmolaliteplasmatique plus elevee. Les animaux infestes n'ont pas reussi a faire augmenter significativement Im autant que les animaux sains et ils affichaient une difference d'hematocrite. Heureusement, le test de provocation a l'hypersalinitea aussi causele detachement et la mort des adultes d'A. funduli. Nous concluons que les lesions provoquees par A. funduli perturbent le transport des sels dans les membranes affectees, mais qu'elles n'affectent pas significativement la survie lors d'un test de provocation a l'hypersalinite´; l'exposition a des conditions hypersalines est un traitement efficace contre les infestations aArgulus chez ces poissons fortement hyperhalins. (Traduit par la Redaction)