Two new species of entobdelline (capsalid) monogeneans are described from the skin of Australian dasyatid stingrays, namely Neoentobdella cribbi sp. n., a small parasite from the estuarine stingray, Dasyatis fluviorum Ogilby (Elasmobranchii: Dasyatidae) and Neoentobdella baggioi sp. n., a relatively large parasite from the porcupine ray, Urogymnus asperrimus (Bloch et Schneider) (Elasmobranchii: Dasyatidae). A striking feature of both of these new parasite species is a pad, possibly located within the genital atrium, armed with rows of closely spaced, rod-shaped microsclerites. Both species also possess a muscular papilla in the genital tract and a club-shaped structure near the common genital opening on the left lateral margin of the body. In N. cribbi, the latter feature is large and located anterior to the genital pad and in N. baggioi, it is small and located in a more posterior position. Similar embellishments in the genital area occur in N. natans Kearn et Whittington, 2005 and in N. parvitesticulata Kearn et Whittington, 2005, while other species (e.g. N. garneri Whittington et Kearn, 2009 and N. taiwanensis Whittington et Kearn, 2009) lack these features and differ also in functional aspects of the male copulatory apparatus and the haptor. Separate generic status for these two groupings is indicated, but must await a comparative and comprehensive review of all Neoentobdella spp.
Two new nematode species, Philometra strongylurae sp. n. and Philometra tylosuri sp. n., are described from female specimens collected from needlefishes (Belonidae, Beloniformes) off the Fao coast, Basrah, Persian Gulf, in Iraq. Philometra strongylurae (gravid females with larvae) was recorded from the subcutaneous tissue, muscles of beak and gills of Strongylura leiura (type host) and S. strongylura, whereas P. tylosuri (nongravid females) from the musculature and the subcutaneous tissue of Tylosurus crocodilus. The former is characterized mainly by the presence of eight markedly large cephalic papillae, conspicuously large anterior oesophageal bulb and by the length of body (15-20 mm); the latter by eight minute cephalic papillae, poorly developed oesophageal bulb and by the body length (46-72 mm). A key to Philometra spp. with gravid females parasitic in the subcutaneous tissue, fins or musculature of fishes is provided.
Two new nematode species of Philometra Costa, 1845, P. carolinensis sp. n. and P. cynoscionis sp. n., are described from the spotted seatrout, Cynoscion nebulosus (Cuvier) (Sciaenidae, Perciformes) in estuaries on the Atlantic coast of South Carolina, USA. Philometra carolinensis (males and gravid and subgravid females) parasitic in the host's ovary is most similar to P. lateolabracis (Yamaguti, 1935) in female morphology, but distinctly differs from it in possessing conspicuously short spicules (81-87 µm long) with heavily sclerotized distal parts, the gubernaculum bearing a reflected dorsal barb, and in the length ratio of the gubernaculum and spicules (1:1.23-1.42) in the male. Philometra cynoscionis (only gravid females) found subcutaneously in the host's tissue (lateral to the ascending process of the premaxilla and also posteromedial to the length of each maxilla) is characterized mainly by the presence of cephalic papillae arranged in two circles (8 large papillae in outer circle and 6 small papillae in inner circle), the absence of caudal projections, the body size (length of gravid female 20-33 mm) and the location in the host.
Two new philometrid nematodes, Philometra overstreeti sp. n. and Philometroides paralichthydis sp. n., are described from female specimens collected from the southern flounder Paralichthys lethostigma Jordan et Gilbert (Paralichthyidae, Pleuronectiformes) in estuaries of South Carolina, USA. P. overstreeti is characterized by the presence of eight large, equal in size cephalic papillae, the absence of caudal projections, the body length of gravid females (14.10-27.06 mm) and the location in the host (among teeth). P. paralichthydis from the host's fins and the buccal cavity differs from its congeners mainly in possessing longitudinal cuticular ornamentations in addition to transverse ones or individual rounded bosses. It is the first species of Philometroides reported from flatfishes (Pleuronectiformes). A re-examination of type specimens of Margolisianum bulbosum Blaylock et Overstreet, 1999 showed that, in fact, nematodes belonging to two different species (now described to be new to science) and genera were confused in the original description of this taxon and in the diagnosis of Margolisianum. Since the male holotype of M. bulbosum cannot be identified to genus, Margolisianum bulbosum is a species inquirenda and a species incertae sedis. Consequently, Margolisianum becomes a genus inquirendus.
Protogyrodactylus ethiopicus sp. n. and P. kritskyi sp. n. are described from the gills of Gerres nigri Günther (Gerreidae, Perciformes) captured from the estuary of the Sine-Saloum River (Senegal, West Africa). These new species differ from previously described species within the genus by a mid- or dextro-ventral vaginal opening (dextral in all other species). They are part of a morphological species group within Protogyrodactylus Johnston et Tiegs, 1922 that has the tip of the superficial root of the ventral anchor resembling a hook and two anterior projections on the anterior margin of the ventral bar. Protogyrodactylus ethiopicus differs from the remaining species in this group mainly by the morphology of the base of the male copulatory organ (MCO), which is disk-shaped, and the shape of the anterior projections of the ventral bar (round in the new species and relatively elongate in the other species of the group). The other new species, P. kritskyi, differs from all others in the same morphological group in having a MCO with a greatly expanded base that bears a heel-like subterminal sclerotization.
Two new lung-dwelling nematode species of the genus Rhabdias Stiles et Hassall, 1905 were discovered in Caxiuanã National Forest, Pará state, Brazil. Rhabdias galactonoti sp. n. was found in a dendrobatid frog Adelphobates galactonotus (Steindachner). The species is characterised by the regularly folded inner surface of the anterior part of the buccal capsule seen in apical view, flask-shaped oesophageal bulb and narrow, elongated tail. Rhabdias stenocephala sp. n. from two species of leptodactylid frogs, Leptodactylus pentadactylus (Laurenti) (type host) and L. paraensis (Heyer), is characterised by a narrow anterior end that is separated from the remaining body by a constriction. Both species possess six small but distinct lips, a cuticle that is inflated along the whole body, a doliiform buccal capsule separated into a longer anterior and a shallow, ring-shaped posterior part, lateral pores in the body cuticle and zones of spermatogenesis in the syngonia. Rhabdias galactonoti sp. n. is the first species of the genus found in Dendrobatidae; R. stenocephala sp. n. is the second species described from Leptodactylidae in eastern Amazonia., Yuriy Kuzmin, Francisco Tiago de Vasconcelos Melo, Heriberto Figueira da Silva Filho, Jeannie Nascimento dos Santos., and Obsahuje bibliografii
Two new species of rhabdochonid nematodes are described from the intestine of freshwater fishes in Chiang Mai Province, northern Thailand: Rhabdochona (Rhabdochona) pseudomysti sp. n. from the catfish Pseudomystus siamensis (Regan) (Bagridae, Siluriformes) in the Fang Brook, a tributary of the Kok River (the Mekong River basin), Fang District and Rhabdochona (Globochona) thaiensis sp. n. from the cyprinid Mystacoleucus marginatus (Valenciennes) (Cyprinidae, Cypriniformes) in the Ping River (the Chao Phraya River basin), Muang District. Rhabdochona pseudomysti is mainly characterized by simple, leaf-like oval deirids (a unique feature among Rhabdochona spp.), a prostom with 14 anterior teeth, the presence of basal prostomal teeth, the length ratio of the muscular and glandular portions of oesophagus (1:2.1-2.6), an unusually long left spicule (1.10-1.22 mm), length ratio of spicules (1:11.5-14.7), arrangement of genital papillae, and conspicuously elevated vulval lips. Rhabdochona thaiensis differs from other representatives of the subgenus Globochona Moravec, 1972 possessing caudal projections on the tail tip in that it has only 2 claw-shaped projections located ventrally on the tail tip of both males and females; the species is mainly characterized by the presence of distinct pseudolabia, 8 anterior prostomal teeth, absence of basal teeth, bifurcated deirids, length ratio of the muscular and glandular portions of oesophagus (1:11.3-11.9), conspicuously short (135-141 µm) left spicule, arrangement of genital papillae, and somewhat elevated vulval lips. Fully developed eggs of R. pseudomysti and R. thaiensis remain unknown. These are the first nominal species of Rhabdochona reported from Thailand.
Rhodeus cyanorostris sp. nov. and R. nigrodorsalis sp. nov. are described from two tributaries of the River Yangtze, in Sichuan and Jiangxi Provinces, China, respectively. Both species have a small number of branched dorsal-fin rays (both with a mode of 8) and anal-fin rays (mode of 7-8 and 8, respectively), which makes them easily distinguished from all congeners. Rhodeus cyanorostris sp. nov. differs from R. nigrodorsalis sp. nov. in having more predorsal scales (14-16 vs. 12-13), fewer pectoral-fin rays (10-11 vs. 12), a shorter major axis of the eggs (2.5-2.8 mm vs. mostly 3.3-3.5 mm), absence of two rows of light spots on the dorsal-fin rays (vs. presence), and absence of a black blotch on the dorsal fin in adult males (vs. presence). The breeding season in winter of the two new species is unique among the Acheilognathinae.
Morphological and molecular analyses of cestode specimens collected during survey work of batoid elasmobranchs and their parasites in Senegal revealed two new species of the rhinebothriidean cestode genus Stillabothrium Healy et Reyda 2016. Stillabothrium allisonae Dedrick et Reyda sp. n. and Stillabothrium charlotteae Iwanyckyj, Dedrick et Reyda sp. n. are both described from Fontitrygon margaritella (Compagno et Roberts) and Fontitrygon margarita (Günther). Both new cestode species overlap in geographic distribution, host use and proglottid morphology, but are distinguished from each other, and from the other seven described species of Stillabothrium, on the basis of their pattern of bothridial loculi. Phylogenetic analyses based on sequence data for 1,084 bp from the D1-D3 region of 28S rDNA that included multiple specimens of both new species and eight other species of Stillabothrium corroborated the morphologically-determined species boundaries. The phylogenetic analyses indicate that S. allisonae sp. n. and S. charlotteae sp. n. are sister species, a noteworthy pattern given that the two species of the stingray genus Fontitrygon they both parasitise, F. margaritella and F. margarita, are also sister species. Although species of Stillabothrium vary widely in their patterns of facial loculi, the variation does not appear to correlate with phylogeny. Most species of Stillabothrium parasitise myliobatiform elasmobranch genera of the Dasyatidae Jordan. This study brings the number of described species of Stillabothrium to nine, three of which occur in the eastern Atlantic, two of which occur off the northern coast of Australia, and four of which are from coastal Borneo., Elsie A. Dedrick, Florian B. Reyda, Elise K. Iwanyckyj, Timothy R. Ruhnke., and Obsahuje bibliografii
Tanichthys albiventris, new species, from the River Jiangping in Dongxing City, Guangxi Province is distinguished from Tanichthys albonubes by the presence of a reddish-orange dorsal-fin margin (vs. white) and 9-10 (9 in mode) branched anal-fin rays (vs. 8 in mode). Tanichthys flavianalis, new species, from the River Jiuqu in Qionghai City, Hainan Province is distinguished from T. albiventris and T. albonubes by the presence of a golden anal-fin margin (vs. white) and 7 (rarely 6) branched dorsal-fin rays (vs. 6 in mode). In T. albiventris, T. albonubes, and T. flavianalis the black lateral stripe is located on the dorsal half of the flank, distinguishing them from Tanichthys kuehnei and Tanichthys micagemmae, in which it is mid-lateral. Tanichthys thabacensis is different from all other species of Tanichthys in the shape of the mouth and insertion of the anal fin; it is tentatively referred to as Aphyocypris.