Epibiontic communities on the freshwater shrimp Caridina ensifera (Crustacea,Decapoda, Atyidae) from Lake Poso (Sulawesi,Indonesia)

The epibiont communities of the freshwater shrimp Caridina ensifera, endemic to Lake Poso (Sulawesi, Indonesia), were analysed for the first time based on their morphological and biometrical characteristics and taxonomic position. Seven ciliated protozoans and a rotifer were examined: three suctorian ciliate protozoan species (Acineta sulawesiensis, Podophrya maupasi, and Spelaeophrya polypoides), three peritrichs (Zoothamnium intermedium, Vorticella globosa, and Cothurnia compressa), a haptorid (Amphileptus fusidens), and the rotifer species Embata laticeps. A mean number of 314.6 epibionts was found per shrimp specimen. The distribution of the epibiont species on the surface of the basibiont was recorded, to allow calculation of the density on the different colonized individuals of C. ensifera and on each anatomical unit of the shrimp. The most abundant species, Zoothamnium intermedium and Acineta sulawesiensis, were also the ones most widely distributed. The statistical analysis showed that Zoothamnium, Acineta, Podophrya, and Embata were the epibiont genera most widely distributed on the basibiont, and the pairs of epibiont genera Zoothamnium–Embata, Podophrya–Acineta, Spelaeophrya–Amphileptus, and Cothurnia–Vorticella followed a similar pattern of distribution. There was a significant difference between the distribution patterns of the different epibiont species on the shrimp. The analysis of the densities of the epibionts throughout the longitudinal axis of the shrimp showed a gradient from the anterior to the posterior end of the body, and a significantly different distribution of each epibiont species. Their colonization follows a certain pattern of behaviour, the species occupying the available substratum, with particular requirements of each functional group, but with a trend resulting in equilibrium among species and groups, compensating for diversity and density. The possible adaptations of the epibionts, as well as the colonization patterns are discussed.     

Biofouling of the high-shore rockpool harpacticoid copepod Tigriopus brevicornis

The occurrence of microbial epibionts on the exoskeleton of the high-shore rockpool inhabitant Tigriopus brevicornis is described. The major biofoulant is a filamentous bacterium of the genus Leucothrix. Other observed epibionts on the exoskeleton of T. brevicornis include ciliates and diatoms. Harpacticoid copepods have no grooming structures to counteract fouling. Possible effects of these epibionts on the movement and feeding of T. brevicornis are suggested.     

Ciliate—decapod epibiosis in two areas of the north-west Mediterranean coast

A study was carried out of the protozoan ciliate epibionts present on diverse decapod crustaceans from two areas of the north-west Mediterranean. A total of 92 crustaceans was examined (65 brachyurans and 27 anomurans, belonging to 15 species). Seventeen ciliate species were identified (two heterotrichs, two chonotrichs, ten suctorians, and three peritrichs). This is the first record of the family of folliculinid ciliates as epibiont on crustaceans in Mediterranean waters. The suctorian Acinetides symbiotica, considered endemic to Lake Nyassa, was found in the sampling areas. Local variations, microlocation on the surface and anatomical units of the decapods, and differential distribution of epibionts were also considered.     

Parasites of shore crabs in the genus Hemigrapsus (Decapoda: Brachyura: Varunidae) and their status in crabs geographically displaced: a review

Two brachyurans of the varunid genus Hemigrapsus from the northwestern Pacific Ocean have invaded coastal regions of the north Atlantic – Hemigrapsus takanoi (sibling species of Hemigrapsus penicillatus) and Hemigrapsus sanguineus in Europe and the latter in the USA. Parasites are known from these crabs in their native habitats, but except for an undescribed larval nematode, none has been found in those examined from their new locations. These parasites include metacercariae of eight species of microphallid trematode, the rhizocephalan barnacles Polyascus polygenea, Sacculina nigra and Sacculina senta, and the obligate gut-inhabiting mesomycetozoan Enteromyces callianassae (potential parasite). The following have been identified in four of the other eight Pacific crabs within the genus (Hemigrapsus nudus and Hemigrapsus oregonensis, northern hemisphere; Hemigrapsus crenulatus and Hemigrapsus sexdentatus, southern hemisphere), none of which have been geographically displaced: metacercariae of two microphallid trematodes; cystacanths of three acanthocephalans Profilicollis antarcticus, Profilicollis botulus and Profilicollis novaezelandensis; larval nematode Ascarophis sp.; nematomorph Nectonema zealandica; entoniscid isopod Portunion conformis; mesomycetozoan Taeniella carcini; and nemertean egg predator Carcinonemertes epialti. The likelihood of the displaced species of shore crabs being rejoined with their native parasites or their susceptibility to becoming infected by similar parasites in their new locations is discussed. In future global displacements of parasitized Hemigrapsus species it is possible that their most serious parasites, rhizocephalans and entoniscid isopods, may infect previously uninfected species. For example, the two eastern Pacific species of Hemigrapsus (H. nudus and H. oregonensis) may be vulnerable to the rhizocephalans and may in turn be a source of entoniscids transported elsewhere.     

Parasite community of the golden cownose ray Rhinoptera steindachneri Evermann and Jenkins 1891 (Chondrichthyes: Myliobatidae), in Acapulco Bay,Guerrero, Mexico

The parasite community of the ray Rhinoptera steindachneri from Acapulco Bay was examined and quantified; analyses were based on the sex of the host and the date of sampling. A total of 171 specimens of R. steindachneri were examined during July–August of 2010, and May and July of 2012. Twenty-one species of parasites were found: three species of Monogenea; eight adult and one larval species of Cestoda; one larval species of Nematoda; five species of Copepoda; two species of Isopoda; and one species of Hirudinea. Cestodes had the greatest species richness (43% of the total species), followed by the copepods (24%). Two species of cestode, Glyphobothrium sp. and Rhinebothrium sp., were collected only from adult rays. At the component community level, species richness showed statistically significant variation between 13 and 16 species, which is similar to previous reports for other species of rays. The parasite component communities and infracommunities of R. steindachneri exhibited similar patterns: high species number and low numerical dominance by a particular species of parasite. The differences of body size of male vs. female rays, and a change in diet and feeding behaviour with the age of R. steindachneri, are likely important factors in the structuring of their parasite communities.     

Motile homes: a comparison of the spatial distribution of epibiont communities on Mediterranean sea turtles

Understanding the ecological roles performed by an individual species requires knowledge from a wide range of disciplines; here we analyze the epibiont–host relationship found in marine turtles. During the study we recorded five new species of sea turtle epibiont: Laomedea flexuosa, Caprella fretensis, Hyale nilssoni, Hyale schmidti, Parasinelobus chevreuxi; as part of a total of nine zoological epibionts present on 35 female green turtles (Chelonia mydas) and 100 loggerhead turtles (Caretta caretta) nesting in Cyprus. The two most commonly occurring epibionts were acorn barnacles Chelonibia testudinaria and Chelonibia caretta, with larger specimens of both species recorded on loggerhead turtles. We analyzed the spatial distribution of these two barnacle species upon the carapaces of their hosts. Specimens of C. testudinaria situated on the anterior half of the carapace were larger than those located at the posterior. A significantly larger proportion of loggerhead turtles (52.5%) hosted epibionts in comparison to green turtles (30.3%). All non-barnacle epibionts were associated with either posterior algal mats or carapace scars.     

Marine protozoan epibionts on the copepod Lepeophtheirus salmonis,parasite of the Atlantic salmon

Two species of ciliate suctorian protozoa belonging to the genus Ephelota, E. gemmipara and E. gigantea, were found as epibionts on the marine copepod Lepeophtheirus salmonis (salmon louse), an ectoparasite of marine salmonid fish, including the Atlantic salmon, Salmo salar. Epibionts were distributed over the cephalothoracic shield, genital segment, abdomen and caudal branches of the copepods. Individuals from both species possessed two types of tentacles: long, prehensile, pointed tentacles and short, adhesive, capitate feeding tentacles. Both species contained a highly ramified and lobated macronucleus. E. gemmipara showed a rounded cellular body attached to a stalk possessing longitudinal and transversal striations but lacking a suprastylar extension. E. gigantea had an umbrella‐shaped cellular body significantly larger than in E. gemmipara, the stalk showing only longitudinal striations but possessing a conspicuous suprastylar extension. This is the first time that the presence of ciliate epibionts has been recorded at species level on the copepod Lepeophtheirus salmonis. Statistical data about the distribution of both species on the surface of the copepod are detailed and a new geographical distribution for E. gigantea is proposed.     

Carapace epibionts of loggerhead turtles (Caretta caretta) nesting at Canaveral National Seashore,Florida

A survey of the epibionts inhabiting the carapace of loggerhead sea turtles Caretta caretta (Linnaeus) nesting on Canaveral National Seashore, Florida was conducted from 2003–2004. Epibionts were sampled and identified to the lowest taxonomic level possible. Eleven newly documented epibiont species were observed from 52 individual loggerheads. We present the first records of sea urchins as loggerhead epibionts. Data are presented on the behavioural, physical, and ecological characteristics of some of these newly documented species to understand better the relationship between loggerhead turtles and their epibiota.     

Digenetic trematodes from mullets of Visakhapatnam (India)

In the course of a survey carried out on the digenetic trematode fauna of three species of mullets Mugil cephalus, Liza macrolepis and Valamugil cunnesius collected from various brackish water localities at Visakhapatnam, 15 species of adult digenetic trematodes and 9 species of metacercariae were encountered.

The adult digeneans are distributed over 7 families as follows: Transversotrematidae (1), Haploporidae (6), Haplosplanchnidae (2), Lepocreadiidae (1), Gorgoderidae (1), Bunocotylidae (3) and Bivesiculidae (1). Five new species, Haploporus indicus, H. pseudoindicus, Lecithobotrys mugilis, Carassotrema bengalense and Saturnius valamugilis are described. Other species reported are: Transversotrema patialense, Pseudohapladena bengalense, Saccocoelioides martini, Haplosplanchnus purii, H. caudatus, Phyllodistomum lewesi, Crassicutis karwarensis, Saturnius segmentatus, Aphanurus harengulae and Paucivitellosus sp.

The nine species of metacercariae collected from mullets belonged to 5 families: Clinostomidae (1), Heterophyidae (5), Acanthostomatidae (1), Cryptogonimidae (1) and Didymozoidae (1). The various metacercariae collected are: Clinostomum sp., Haplorchis yokogawai, Centrocestus formosanus, Stellantchasmus falcatus, Stictodora sp., Galactosomum ussuriense, Atrophecaecum burminis and Exorchis sp.

The characteristic features of the trematode fauna of mullets are discussed. Support is given to Manter's ecological bridge theory that mullets act as links in the intertransfer of parasites between marine and freshwater habitats.     

Protozoan ciliate epibionts on the freshwater apple snail Pomacea figulina (Spix, 1827) (Gastropoda,Ampullariidae) in an urban stream of south‐east Brazil

The objective of this study was to record and analyze the prevalence of ciliated protozoa associated with prosobranchian snails of the species Pomacea figulina collected from an urban stream in south‐eastern Brazil. Four collections were carried out between December, 2005, and March, 2006, from which 23 snails and 10 ‘empty’ shells were obtained. The shells and opercula were scraped over Petri dishes and the ciliates were observed using bright field and phase contrast microscopy. Seven species of ciliates were recorded on the snails of P. figulina. Of the 23 snails analyzed, 82.60% (n = 19) were infested with at least one species of ciliate. No ciliates were found on the ‘empty’ shells and opercula. The results are discussed in terms of ecological aspects involved in this association.     

Metazoan parasites of Calophysus macropterus (Siluriformes: Pimelodidae) in the Acre and Iaco rivers in the western Amazon region of Brazil: diversity,similarity and seasonal variation

ABSTRACT

The diversity, similarity and seasonal variation of metazoan parasite communities in Calophysus macropterus in the Acre and Iaco rivers, in the western Amazon (Brazil), was investigated. Parasites from 13 taxa were collected from C. macropterus in both rivers: four species of monogeneans, four nematodes, two cestodes, one digenean, one crustacean and one pentastomid. In hosts from the Acre river, Cucullanus pinnai predominated; while in hosts in the Iaco river, Monticellia amazonica predominated. The component communities of the parasites among the hosts in the two rivers presented high similarity (100%). Prevalence of Alinema amazonicum was higher in hosts in the Acre river; while the prevalence of C. pinnai was higher in hosts in the Iaco river and the mean prevalence and abundance of M. amazonica were higher in fish from the Iaco river. Regarding C. macropterus from the Acre river, infection levels by A. amazonicum were higher during the rainy season, while Demidospermus pinirampi only occurred in the dry season and Procamallanus (Spirocamallanus) inopinatus only occurred in the rainy season. In hosts from the Iaco river, infections by larvae of Anisakidae gen. sp. were higher during the dry season, while infection by Rudolphiella piracatinga and Sebekia sp. only occurred in the rainy season. However, P. (S.) inopinatus, Ergasilus callophysus, Ameloblastella unapi, Demidospermus luckyi, Demidospermus macropteri and D. pinirampi only occurred in the dry season. High similarity of the component communities of the parasite was observed between the rainy and dry seasons. These results suggest that factors other than location and seasonality were influencing the communities and infracommunities of the parasites found. Lastly, C. macropterus is a new host for almost 50% of the parasite species found. In addition, the results from the present study have expanded the geographical range of these 13 species of parasites to the western Amazon region.     

Studies on gorgoderid digeneans from Australian and Assian Freshwater fishes

Pseudophyllodistomum gen. nov. is proposed for a section of Phyllodistomum Braun, 1899. The new genus is distinguished by the simple form of the uterus, the eggs which reach over 60 μm long in length, the saccular excretory bladder, the 2[3 + 3 + 3) + (3 + 3 + 3)] = 36 flame-cell formula, the metacercaria which may have fully developed genitalia and is parasitic in decapod crustaceans, the use of corbiculid bivalves as first intermediate hosts, and the cercaria which has a long tail not enclosing the cercarial body. Two species, P. johnstoni sp. nov. and P. murrayense sp. nov., are described from Australian freshwater fish and five new combinations of previously described Phyllodistomum species from Asian freshwater fish are proposed — P. macrobrachicola (Yamaguti, 1934) comb. nov., P. lesteri (Wu, 1938) comb. nov., P. srivastavai (Rai, 1964) comb. nov., P. lucknowense (Pandey, 1970) comb. nov. and P. mingense (Tang, 1985) comb. nov. The first intermediate host of P. johnstoni is a Corbiculina species. The long-tailed cercariae infect the gonads of palaemonid prawns, Macrobrachium spp., in which they grow to unencysted metacercariae which may have fully developed genitalia. The metacercaria of P. murrayense also infects a Macrobrachium species. The evolution of the Gorgoderinae is discussed and it is suggested that, prior to the erection of Pseudophyllodistomum, Phyllodistomum may have encompassed as many as five different phylogenetic lines, each with similar adult morphology but distinguishable by life-cycle characters. It is postulated that more study will lead to further division of Phyllodistomum.     

Ectosymbionts of the non‐indigenous Asian shore crab,Hemigrapsus sanguineus (Decapoda: Varunidae), in the western north Atlantic,and a search for its parasites

Over 560 Asian shore crabs, Hemigrapsus sanguineus, collected mainly in the spring of 2005 and 2006 from rocky intertidal locations in southern New Jersey, were examined for epibionts. Small numbers of the sympatric green crab, Carcinus maenas, and the Atlantic mud crab, Panopeus herbstii, were examined for epifauna to compare with H. sanguineus. Blue mussel spat, Mytilus edulis, and the encrusting, cheilostome bryozoan, Conopeum tenuissimum, were the dominant ectosymbionts of the shore crab, with prevalences of 22.2 and 32.1%, respectively; ranges of intensity were 1–146 spat/crab and 1–31 colonies/crab. Both species are incidental symbionts. Larger crabs had higher prevalences and intensities of C. tenuissimum colonies, and these colonies displayed a distinct pattern of attachment to the carapace which seemed to be related to crab morphology and habitat. Much less common was the encrusting, ctenostome bryozoan Alcyonidium albescens, a facultative symbiont species with a prevalence of 3.4%. Other epibionts were the encrusting, cheilostome Membranipora tenuis, the tubicolous polychaetes Hydroides dianthus, Sabellaria vulgaris, and Spirorbis sp., the barnacles Balanus improvisus and Semibalanus balanoides, and unidentified thecate hydroids, all incidental symbionts with prevalences from 0.2 to 3.2%. The total number of known ectosymbionts of H. sanguineus, including additional species found previously in the USA and the western Pacific, is 13. Carcinus maenas and P. herbstii share some of the same symbionts. Rhizocephalan externae were not observed in any of the crab species used in this study, nor were gill parasites or internal parasites found among 248 specimens of H. sanguineus.     

Abbreviated larval development of the freshwater prawn,Macrobrachium pilimanus (De Man, 1879) (Decapoda,Palaemonidae), reared in the laboratory

The larvae of the freshwater prawn, Macrobrachium pilimanus (De Man, 1879), were reared in the laboratory. Larval development was highly abbreviated, with two zoeal and one megalopal stages. Newly hatched larvae were benthic, with a tendency to cling on to roughened surfaces. All larval stages subsisted solely on endogenous yolk. Morphological and behavioural differences between the first zoea of this species and that of M. malayanum (Roux, 1934) are highlighted. The potential use of larval characters in taxonomy is also discussed.     

An investigation of predator‐induced defence responses in ciliated protozoa

Predator‐induced defence responses have been reported in 15 species of ciliates representing three subclasses: Hypotrichia, Stichotrichia and Hymenostomia. However, the discovery of this phenomenon in such distantly related groups suggests that it could be more widespread within the Ciliophora. In laboratory experiments, we tested 23 potential prey species with a range of potential predators including other ciliates (12 spp.), amoebae (two spp.), rotifers (two spp.), a turbellarian worm (Stenostomum sphagnetorum), and an oligochaete worm (Chaetogaster sp.). In each experiment, one predator species was incubated for 24?h with one potential prey species and the latter was examined for evidence of a defence response. One new example of predator‐induced morphological change was recorded (Euplotes viridis) and detailed observations were made for one poorly known example (E. eurystomus). Both species significantly increased their width (by about 35% and 23%, respectively) in the presence of the turbellarian worm S. sphagnetorum. An induced life cycle change was recorded for the first time among hypotrichs with E. muscorum exhibiting significantly increased rates of encystation in the presence of the ciliate predators Dileptus anser and Spathidium sp. Finally, Euplotes patella, Euplotes sp. and Stylonychia pustulata, which are usually regarded as omnivorous rather than predatory ciliates, all induced morphological change in Colpidium kleini, the C. kleini cells becoming significantly shorter and wider. No examples of induced defence response were found among groups other than hypotrichs and hymenostomes.     

An investigation into the metazoan parasites of the spiny dogfish (Squalus acanthias L.), off the west coast of Ireland

The present study was undertaken to examine the parasite fauna of spiny dogfish, and to determine seasonal variations in infection rates and faunal composition. A total of 10 metazoan parasite species was recorded, of which four species occurred in the intestine, three species were parasitic on the gills, two species occurred on the skin, and one species parasitized the spiracle. However, a cumulative parasite species richness curve indicated that a larger sample may have yielded additional parasite species. The parasite assemblage consisted of five species of copepods (Eudactylina acanthii Scott, Caligus curtis Müller, Pandarus bicolor Leach, Echthrogaleus coleoptratus (Guerin-Meneville) and Pseudocharopinus bicaudatus (Krøyer)), two species of nematodes (Anisakis simplex Rudolphi and Hysterothylacium aduncum (Rudolphi)), two species of cestodes (Trilocularia gracilis Olssen and Gilguina squali (Fabricius)), and one species of monogenean (Erpocotyle abbreviata (Olssen)). The parasite fauna was found to be similar to that of S. acanthias from the North Sea, and from New Zealand waters. Results obtained during the present study indicate that the infection rates of certain parasite species display seasonal cycles, most species displaying their greatest prevalence in spring and their lowest prevalence in autumn.     

A report on two large collections of the squat lobster Munidopsis platirostris (Decapoda,Anomura, Munidopsidae) from the Caribbean,with notes on their parasites,associates, and reproduction

The reproduction and parasite associates of the squat lobster Munidopsis platirostris (A. Milne Edwards and Bouvier, 1894) were investigated based on collections made in the Bahamas and Curaçao with grassmat and bundled fishing net traps used to collect sipunculan worms and other small invertebrates. Size of ovigerous M. platirostris was significantly correlated with clutch size for females from both localities but females from the Bahamas produced significantly more eggs (on average 10.1 eggs/clutch) than females from Curaçao (on average 6.6 eggs/clutch). Early embryos of M. platirostris from the Bahamas were 0.74–0.82 mm in diameter, similar to some other species of Munidopsidae as well as Chirostylidae. Two species of crustaceans, another squat lobster and a leptostracan, as well as a limpet mollusc, were collected with M. platirostris in the Bahamas, while a sipunculan was an associated species in a Curaçao collection. One specimen of M. platirostris had an unidentified cryptoniscoid epicaridean isopod, possibly representing a new genus and species. Two specimens of M. platirostris each had one rhizocephalan externa of a species belonging to Lernaeodiscus Müller, 1862 but their morphology does not match that of L. schmitti Reinhard, 1950, the only species in the genus known from squat lobsters in the western Atlantic. Additional materials and tools, such as DNA analysis, are needed to describe these potentially new parasites and we suggest that use of these traps may be an effective method to obtain additional samples.     

Aspects of the life history and origins of Nesolecithus africanus (cestoda: Amphilinidea)

Larvae of the amphilinidean platyhelminth Nesolecithus africanus are reported and described from the freshwater prawn Desmocaris trispinosa in Nigeria. The worms were found in the haemocoel of female prawns and appear to restrict ovarian development. Taxonomic, zoogeographical and evolutionary relationships of the species with its South American relative, N. janickii, are discussed. These species are very similar morphologically, and restricted to parts of the African and South American continents which were adjacent in Cretaceous times. They are probably vicariant Gondwanaland relicts, little changed over the past 100 million years. Two theories of amphilinidean origin are discussed.     

The epibionts of beach hoppers (Crustacea: Talitridae) of the North American Pacific coast

The beach hoppers Megalorchestia californiana and M. corniculata (Crustacea: Talitridae) were studied for the interaction of two of their epibionts. Rhabditid nematodes reside under the host's dorsal pereonites where they may be facultative parasites or feed on bacteria and detritus associated with the host. The mite Thinoseius brevisternalis (Canaris, 1962) (Acari: Eviphididae) preys upon the above nematodes. Both nematodes and mites also use the host as transport between patches of beach wrack. Other epibiotic Acari on talitrids are also reported here.