Dendrorchis pampae sp. n. (Digenea: Gorgoderidae) from Cynopoecilus melanotaenia (Cyprinodontiformes: Cynolebiidae) a killifish from southern Brazil, with an emended diagnosis of Dendrorchis

A new species of Dendrorchis is described and compared with others in the genus. The parasites were found in the swim bladder of the annual killifish Cynopoecilus melanotaenia. Hosts were collected from a seasonal wetland in southern Brazil. The main characteristics of D. pampae are: genital pore in the intestinal bifurcation region elongate and lobed vitellaria uterine loops limited to the acetabular region and to the rear end of the body; and wide intestinal caeca. An emended diagnosis of the genus Dendrorchis includes the characteristics of the new species. This is the first record of an adult digenean in an annual killifish from South America.

Description of Neolepidapedoides subantarcticus sp. nov. (Digenea, Lepocreadiidae) from sub-Antarctic notothenioid fishes

Neolepidapedoides subantarcticus sp. nov. (Digenea, Lepocreadiidae) is reported from the intestine, mainly the jejunum, of fishes in the eastern mouth of the Beagle Channel and in the harbour of Ushuaia in the Beagle Channel (Tierra del Fuego, Argentina) at a depth 7–30 m. The typical host is Patagonotothen longipes, other hosts are P. tessellata, P. brevicauda and Champsocephalus esox. The male terminal genitalia indicates that the new species belongs to the genus Neolepidapedoides (Lepocreadiidae, Lepocreadiinae). The most important taxonomic features are the presence of eye-spots, the spined tegument, the “Opechona-type” cirrus-sac, the external seminal vesicle free in the parenchyma, the gonads arranged in tandem, the vitelline follicles extending from the level of the oesophagus in the forebody to the posterior end of the body and an I-shaped excretory vesicle reaching to the intestinal bifurcation and the absence of a pseudoesophagus. Ten previously described species differ from the N. subantarcticus sp. nov. mainly in the extent of the vitelline fields and length of the excretory vesicle which reaches into forebody.

Trematodes from Red Sea fishes: Prosteganoderma brayi gen. nov., sp. nov. (Zoogonidae Odhner, 1902) and Forticulcita mugilis sp. nov. (Haploporidae Nicoll, 1914)

Specimens of the fishes Scarus ghobban Forsskål (Scaridae) and Crenimugil crenilabis Forsskål (Mugilidae) were caught in the Red Sea off the coast of Sharm El-Sheikh, South Sinai, Egypt. Ten (20 %) and 15 (50 %) of these fishes, respectively, were found to harbour intestinal trematodes. Scarus ghobban was parasitised by Prosteganoderma brayi gen. nov., sp. nov. (Zoogonidae) and C. crenilabis by Forticulcita mugilis sp. nov. (Haploporidae). Prosteganoderma gen. nov. is similar to Steganoderma Stafford, 1904, but clearly differs from it and from all the other genera of the subfamily Lepidophyllinae Stossich, 1903 in having a large ventral sucker surrounded by a large prominent fleshy fold of the body wall and a pre-testicular uterus. Forticulcita mugilis sp. nov. is similar to F. glabra Overstreet, 1982, the type and the only species of the genus, but clearly differs in having a larger body size, a longer forebody, an intestinal bifurcation in the middle of the body, subequal gonads, Laurer’s canal opening dorsally at a considerable distance posterior to the testis and a much larger egg size.

Astiotrema turneri n. sp. (Digenea: Plagiorchiidae) from cichlid fishes (Cichlidae: Perciformes) of Lake Malawi, south-eastern Africa

Astiotrema turneri n. sp. is described from the cichlid species Pseudotropheus zebra, P. emmiltos, Labeotropheus trewavasae and Melanochromis vermivorus from Lake Malawi. It differs from Astiotrema reniferum (as described by Yeh & Fotedar 1958) in its distinctly broader body, the much smaller cirrus-sac, its oblique testes, the shorter ventral sucker to ovary distance, the vitellarium reaching into the forebody and the extracaecal uterus; from Astiotrema impletum in the sucker-ratio, the longer caeca, the smaller cirrus-sac and the extracaecal uterus; and from Glossidium pedatum (and its probable synonyms Astiotrema lazeri and Afromacroderoides lazerae) in its much broader body shape, in its distinct oesophagus, the intestinal bifurcation in the posterior forebody, in the distinctly oblique testes, the extracaecal uterus and the vitellarium reaching well into the forebody.

An exceptionally rich complex of Sanguinicolidae von Graff, 1907 (Platyhelminthes: Trematoda) from Siganidae, Labridae and Mullidae (Teleostei: Perciformes) from the Indo-West Pacific Region

We describe an unprecedented radiation of sanguinicolid blood flukes (Digenea: Sanguinicolidae) from two species of Labridae (Choerodon venustus and C. cauteroma), seven species of Mullidae (Mulloidichthys vanicolensis, Parupeneus barberinoides, P. barberinus, P. bifasciatus, P. cyclostomus, P. indicus and P. multifasciatus) and ten species of Siganidae (Siganus argenteus, S. corallinus, S. doliatus, S. fuscescens, S. lineatus, S. margaritiferus, S. puellus, S. punctatus, S. virgatus and S. vulpinus) from sites off Australia and Palau. The flukes were morphologically similar in having the combination of a long thread-like body, tegumental spines in lateral transverse rows, a vestigial oral sucker bearing concentric rows of fine spines, an H-shaped intestine, a cirrus-sac, a notch level with the male genital pore, a lateral or post-ovarian uterus, a uterine chamber and separate genital pores. These species are divided into two genera on the basis of testis number. Sanguinicolids from Siganus fuscescens have a single large testis between the intestinal bifurcation and the ovary and are placed in Ankistromeces Nolan & Cribb, 2004. Species from the remaining nine species of Siganidae, Labridae and Mullidae are placed in Phthinomita n. g.; these species have two testes, the anterior testis being large and between the intestinal bifurcation and the ovary whereas the small posterior testis is at the posterior end of the body and appears rudimentary or degenerate and probably non-functional. The second internal transcribed spacer (ITS2) of ribosomal DNA (rDNA) from 29 host/parasite/location combinations (h/p/l) was sequenced together with that of Ankistromeces mariae Nolan & Cribb, 2004 for comparison. From 135 samples we found 19 distinct genotypes which were interpreted as representing at least that many species. Replicate sequences were obtained for 25 of 30 h/p/l combinations (including A. mariae); there was no intraspecific variation between replicates sequences for any of these. Interspecific variation ranged from 1–41 base differences (0.3–12.7% sequence divergence). The 19 putative species were difficult to recognise by morphological examination. We describe 13 new species; we do not describe (=name) six species characterised solely by molecular sequences and three putative species for which morphological data is available but for which molecular data is not. We have neither morphological nor molecular data for sanguinicolids harboured in five hosts species (Siganus margaritiferus, S. puellus, Choerodon cauteroma, Parupeneus indicus and P. multifasciatus) in which we have seen infections. Where host species were infected in different localities they almost always harboured distinct species. Some host species (for example, S. argenteus and S. lineatus from Lizard Island) harboured two or three species in a single geographical location. This suggests that, for parts of this system, parasite speciation has outstripped host speciation. Distance analysis of ITS2 showed species from each host family (Siganidae, Mullidae and Labridae) did not form monophyletic clades to the exclusion of species from other host families. However, a host defined clade was formed by the sequences from sanguinicolids from S. fuscescens.

Description of a new species of Dolichorchis (Digenea, Diplostomidae) in the cocoi heron, Ardea cocoi (Aves, Ardeidae), from Argentina

Dolichorchis lacombeensis sp. nov., a digenean parasite of the gut of the cocoi heron, Ardea cocoi (L.), is described as a new species from Buenos Aires Province, Argentina. This new species most closely resembles D. buteii and D. tregenna in the distribution of the vitelline follicles, which reach the intestinal bifurcation in the forebody. D. buteii can be distinguished from D. lacombeensis sp. nov. by the distribution of the vitelline follicles in the hindbody, which are concentrated in midline, by the presence of a sphincter in genital pore and by the size of holdfast organ and posterior testis, which are larger, (240–400 × 176–240 and 315–464 × 240–410 µm, respectively). D. tregenna differ from the new species by their larger measurements (pseudosuckers’ length 90–100, pharynx 52–90 × 50–70 and eggs 89–104 × 48–68 µm).

Trematodes from Red Sea fishes: Pachycreadium lethrini sp. nov. (Opecoelidae Ozaki, 1925) and Pseudometadena aegyptensis sp. nov. (Cryptogonimidae Ward, 1917), with a review of their genera

Specimens of the fishes Lethrinus nebulosus Forsskål (Lethrinidae) and Diplodus noct Valenciennes (Sparidae) were caught in the Red Sea off the coast of Sharm El-Sheikh, South Sinai, Egypt. Ten (33%) and 12 (24%) of these fishes, respectively, were found to harbour intestinal trematodes. L. nebulosus was parasitised by Pachycreadium lethrini sp. nov. (Opecoelidae) and D. noct by Pseudometadena aegyptensis sp. nov. (Cryptogonimidae). P. lethrini sp. nov. is unique in having distinctly unequal testes, contiguous gonads arranged obliquely in the right side of hindbody and a small egg size. However, it differs from each of the other three species of the genus in several other features: from P. gastrocotylum (Manter, 1940) Manter, 1954 in having a smaller sucker ratio and vitelline follicles terminating anteriorly at the level of intestinal bifurcation; from P. carnosum (Rudolphi, 1819) Cortini et Ferretti, 1959 in having a smaller body, a smaller sucker ratio, a genital pore situated ventrally to the anterior border of pharynx, a pretesticular ovary and vitelline follicles extending anteriorly to the level of intestinal bifurcation; and from P. lerneri Sogandares-Bernal, 1959 in having a larger body, a smaller sucker ratio and an unlobed ovary. P. angolensis Aleshkina et Gaevskaya, 1985 is considered an invalid species in Pachycreadium. P. aegyptensis sp. nov. is similar to P. celebesensis Yamaguti, 1952, but mainly differs in having a larger pharynx, a much shorter oesophagus, extensive vitelline acini and a shorter seminal vesicle. Pachycreadium Manter, 1954 and Pseudometadena Yamaguti, 1952 are briefly reviewed.

Trematodes from Red Sea fishes: Proneohelicometra aegyptensis gen. nov., sp. nov. (Opecoelidae Ozaki, 1925) and Neohypocreadium gibsoni sp. nov. (Lepocreadiidae Odhner, 1905)

Specimens of the fishes Pterois volitans Linnaeus (Scorpaenidae) and Chaetodon auriga Forsskål (Chaetodontidae) were caught in the Red Sea off the coast of Sharm El-Sheikh, South Sinai, Egypt. Five (20%) and 20 (44%) of these fishes, respectively, were found to harbour intestinal trematodes. P. volitans was parasitised by Proneohelicometra aegyptensis gen. nov., sp. nov. (Opecoelidae) and C. auriga by Neohypocreadium gibsoni sp. nov. (Lepocreadiidae). Proneohelicometra gen. nov. is similar to Neohelicometra Siddiqi et Cable, 1960 which is the only opecoelid genus having caeca opening with separate ani and eggs with unipolar filaments, but differs significantly from it in having two lateral folds of body wall extending along the posterior third of body, an oral sucker smaller than the ventral sucker, a median cirrus sac not reaching the ventral sucker posteriorly and a median genital pore situating immediately posterior to the intestinal bifurcation. Neohypocreadium gibsoni sp. nov. is similar to the other four species of the genus, but is unique in having a distinctly pear-shaped body and a much smaller egg size, and differs significantly from each in several other characters: from N. longisaccatum, it differs in having a cirrus sac not reaching the testes and a pretesticular ovary; from N. dorsoporum in having an external seminal vesicle much shorter than the cirrus sac, a longer cirrus sac extending posteriorly to the level of the posterior margin of the ventral sucker and a pretesticular ovary; from N. chaetodoni in having a smaller body size, symmetrical testes, a longer cirrus sac extending posteriorly to the level of the posterior margin of the ventral sucker and a trilobed ovary; and from N. aegyptense in having a smaller body size, symmetrical testes, a longer cirrus sac extending posteriorly to the level of the posterior margin of the ventral sucker, a trilobed ovary and vitelline follicles terminating anteriorly at the level of oesophagus. Neohypocreadium Machida et Uchida, 1987 is briefly reviewed.

Morphology, histochemistry and the biological significance of the lymphatic system of the trematodeOrthocoeliumscoliocoelium

ABSTRACTThe gross morphology and histological and cytological architecture of the lymph system ofOrthocoelium scoliocoeliumwere studied. Each main vessel, near the intestinal bifurcation forms a spindle-shaped sinus. Lymphocytes, similar to the primitive blood cells, have been seen to form aggregates in certain regions of the lymph system. In addition, detailed histochemical observations were made on the localization and distribution pattern of various phosphatases, esterases and dehydrogenases. It is suggested that the lymph system, in addition to the functions already known, may also selectively reabsorb certain important outgoing higher fatty acids from the excretory system. Furthermore, the lymphocytes may also be involved in the defence mechanism of the worm. The nature and function of fine granules in the lymph remain speculative.

Mesocoelium malayanum sp.n. (Digenea: Brachycoeliidae) in a frog, Rana macrodon Dumeril and Bibron 1941, from Malaysia

ABSTRACTMesocoelium malayanum sp.n. is described from the frog Rana macrodon, in Malaysia. Elongate body, broader anteriorly, measuring 1·900 (1·679–2·070) mm long by 0·404 (0·380–0·437) wide, tegument aspinose oral sucker 0·212 (0·200–0·228) by 0·202 (0·191–0·205), acetabulum 0·141 (0·132–0·150) by 0·139 (0·123–0·146), prepharynx present, oesophagus 0·115 (0·096–0·137), caeca reaching posterior ⅓ of body, anterior testis 0·097 (0·087–0·110) by 0·091 (0·087–0·100) dorsal to acetabulum, posterior testis 0·094 (0·087–0·101) by 0·092 (0·091–0·100), cirrus pouch 0·121 (0·111–0·130) by 0·047 (0·041–0·055), genital pore at left of midline of oesophagus just anterior to intestinal bifurcation, ovary 0·110 (0·091–0·127) by 0·089 (0·085–0·096) on left of body and posterior to acetabulum, vitelline glands with single follicles extending from intestinal bifurcation to ends of caeca, excretory vesicle I-shaped and eggs 0·040 (0·037–0·046) by 0·023 (0·022–0·024). Although morphologically related to M. maroccanum and M. meggitti, M. malayanum is considered to be a new species.