Chromadoridae (Chromadorida: Nematoda) from the Indian Ocean: Difficulties in morphological identification of Actinonema Cobb, 1920 and Rhips Cobb, 1920.

The diagnostic characteristics of ActinonemaCobb, 1920 and Rhips Cobb, 1920 are reviewed andtheir importance for genera diagnosis assessed. Threespecies of Actinonema and one species of Rhips are described. Actinonema longicaudatumSteiner, 1918 is characterised by short (2–3 µmlong) anterior sensilla, cylindrical body with arather narrow anterior end, lateral alae with invertedV-patterns, wide (70–75 of cbd) double amphids andaccessory pieces composed of only the telamon which isbroad anteriorly and tapers on the posterior and along tail. Actinonema paraceltica ischaracterised by long (4–5 µm) anterior sensilla,large amphids (83–88% of cbd), lateraldifferentiation of V pattern on each annule andaccessory pieces with telamons that have shortextensions. Actinonema smolae sp. n. ischaracterised by long and thin body, large amphidslocated close to the anterior end and six solid cones.Rhips reginae n.sp. is characterised by sixsolid cones, large (90% cbd) amphids, lateraldifferentiation of two longitudinal rows of dots anddouble jointed spicules.     

Deep-sea nematodes from the Indian Ocean: new and known species of the family Comesomatidae

Twelve new and known species of the genera Sabatieria,Cervonema, Paramesonchium, Hopperia and Dorylaimopsis and one new genus, Kenyanema aredescribed from the Indian Ocean and S. pisinna Vitiello,1970 from the Mediterranean Sea. Sabatieria lucia sp. n.is characterised by short but distinct inner and setiformouter labial sensilla and long (4–5 µm or 30–33% hd)cephalic sensilla; S. conicauda Vitiello, 1970, ischaracterised by tiny inner and outer labial sensilla andsetiform cephalic ones and short and thick cylindrical tail;Sabatieria pisinna is characterised by short innerand outer labial sensilla, setiform (3µm long) cephalicsensilla, multispiral amphids with 3.25–3.5 turns and a tailwhich is conical in the anterior 2/3 and posterior 1/3cylindrical; Cervonema tenuicauda Schuurmans Stekhoven,1950, is characterised by anterior sensilla in twocircles which are equal in length (3µm long), multispiralamphids with 3–4 turns and located at 1.5 times hd from theanterior end, simple spicules one abd long and 6–7 fineprecloacal supplements; Cervonema minutus sp. n.characterised by an extremely attenuated anterior end,spiral amphids with 4–5 turns (80–90% cbd) and short,simple spicules (0.8 abd long); Cervonema gourbaulti sp.n. characterised by long (4–5 µm) labialand cephalic sensilla, spiral amphids with 5–6 turns(73–88% cbd) and an elongate crenate terminal pharyngealbulb; Paramesonchium mombasi sp. n. characterised bylong labial (5 µm) and cephalic (21 µm) sensilla thatare close together and wide amphids (80–90% cbd); Kenyanema monorchis gen. et sp. n. characterised bya head region narrower than the rest of the body, fourcephalic sensilla (3 µm long) and spiral amphids with1.5–2 turns; Hopperia indiana sp. n. characterised byshort conical anterior sensilla, arcuatespicules that have a velum and a gubernaculum with a longand sharp pointed apophysis; Dorylaimopsis coomansi sp.n. characterised by long (8–10µm) cephalic setae,cuticular punctation with lateral differention of irregularlyarranged dots at the pharyngeal region and 1–3longitudinal rows of dots posterior of the pharynx; spiculeswith a unique shape; Dorylaimopsis gerardi sp. n.characterised by short setiform labial and long (6–7 µm)cephalic sensilla, punctated cuticle with lateraldifferentiation of irregularly arranged dots at firstthen three or four irregularly arranged longitudinal rows atthe pharyngeal and tail regions and two regularly arrangedlongitudinal rows of dots on the rest of the body, aconico-cylindrical tail with a distinctly swollen tip;Dorylaimopsis variabilis sp. n. is characterised byshort labial and setiform cephalic sensilla (33–58% hd),multispiral amphids with three turns, cuticular punctationswith lateral differentiation of three longitudinalrows at the pharyngeal and tail regions and two longitudinalrows on the rest of the body, spicules that are thin andslightly arcuate. The position of S. pisinna accordingto the grouping of Platt, 1985 of Sabatieriaspp. is also discussed. Kenyanema monorchis representsthe first monorchic species in the family.     

Population Dynamics and Description of Ptycholaimellus hibernus n. sp. (Nematoda: Chromadoridae)

Ptycholaimellus hibernus n. sp. from the muddy subtidal of North Inlet Estuary, Georgetown, South Carolina, is described and a key to the genus is provided. P. hibernus differs from all other species of Ptycholaimellus by the shape of the gubernaculum. Ptycholaimellus sp. 2 Hopper 1969 is synonymized with P. ponticus. The abundance of P. hibernus, measured over a 3-year period, is greatest from January to March, coinciding with minimal annual water temperatures (10-15 C). P. hibernus abundance was significantly (negatively) correlated with water temperature and (positively) with the depth of the anoxic sediment layer.     

Description of two new species of Santelmoa (Teleostei, Zoarcidae) from the Southern Ocean

Detailed examination of eelpouts in collected material from the Gerlache Strait and the Bellingshausen Sea, during the Spanish Antarctic Expeditions Bentart 03 and Bentart 06, and from the Bransfield Strait, during the Danish Galathea 3 Expedition, at depths between 1,056 and 1,837?m, revealed two undescribed species of Santelmoa Matallanas 2010. Herein, Santelmoa fusca sp. nov. and Santelmoa antarctica sp. nov. are described on the basis of twelve specimens. Santelmoa fusca can be separated from all other Santelmoa species by the following characters: mouth terminal; two posterior nasal pores; lateral line double; two irregular rows of palatine teeth; dorsal fin rays 109–113; anal fin rays 88–94; vertebrae 27–29?+?87–91?=?114–118; two pyloric caeca well developed; scales reduced to tail; pelvic fins and vomerine teeth present. Santelmoa antarctica can be separated from all other Santelmoa species by the following characters: mouth subterminal; two posterior nasal pores; suborbital pores seven (6?+?1); lateral line double; single row of palatine teeth; supraoccipital dividing the posterior end of frontals; central radials notched; dorsal fin rays 109–112; anal fin rays 89–93; vertebrae 27?+?89–92?=?116–119; two pyloric caeca well developed; scales, ventral fins and vomerine teeth present. Santelmoa fusca and S. antarctica can readily be separated from each other by squamation (reduced to tail vs. on the tail and on the posterior part of body); suborbital pore pattern (6?+?0 vs. 6?+?1), as well as several morphometric characters. The relationships of the two new species with congeners are discussed.     

A new species of Xiphinema americanum group (Nematoda: Longidoridae) from Iran,with additional data on three known species

Systematic Parasitology - One new and three known species of the genus Xiphinema from the rhizosphere of fruit trees and rose shrubs in East Azarbaijan province, Iran, are presented based on the...     

A new species of Vanbenedenia Malm, 1860 (Copepoda: Lernaeopodidae) from the Southern Indian Ocean

A rare find of the elusive genus Vanbenedenia off the south-eastern coast of South Africa on a Hydrolagus sp. proved to be an as yet undescribed species. Vanbenedenia hydrolagae n. sp. differs from the three other species of the genus by virtue of the relative length of the second maxillae, the absence of multiple setae on the exopod of the first maxilla and the bifid nature of the sclerotised hook and sub-terminal seta of the maxilliped. SEM micrographs provided information on the mouth-cone.     

Acantholaimus (chromadoridae:nematoda) from the Indian Ocean: description of seven species

Seven species of the Acantholaimus aredescribed. Acantholaimus vermeuleni sp.n. ischaracterised by labial and cephalic sensilla thatare located at the same level, two post amphidialsetae on the dorso-lateral side and a poorlydeveloped stoma without distinct teeth. Acantholaimus verscheldi sp.n. is characterised bya narrow elongate pharyngeal region, a long stomawith distinct teeth and short (4–7 µm) cephalicsensilla. Acantholaimus heipi sp.n. ischaracterised by a narrow elongate pharyngealregion, well developed teeth in the stoma and longcephalic sensilla (11–13 µm). Acantholaimuselegans Jensen 1988 has a narrow anteriorpharyngeal region that increases in lengthposteriorly, it has setae before and after theamphids on both sides and stoma with well developedteeth. Acantholaimus gathumai sp.n. ischaracterised by long cephalic (10–15 µm) andsomatic (8–10 µm) setae and lateraldifferentiation with fine dots (5–7 µm inwidth). Acantholaimus geraerti sp.n. has longcephalic sensilla (15–19 µm) and narrow (4–6 µm)distinct lateral differentiation. Acantholaimusinvaginatum sp.n. is characterised byvery long cephalic setae (16–21 µm), severalsetae at the pharyngeal region and wide lateraldifferentiation with fine dots, often the stoma isinvaginated. Distribution of the different species of Acantholaimus encoutered in the four transectsstudied is also described.     

Two new species of Xiphinema (Nematoda: Dorylaimida) from Colombia

Summary Two new species of Xiphinema are described from Colombia. X. colombiense n.sp. is characterized by a continuous lip region, a median vulva with both genital tracts fully developed and without Z-differentiation, a total stylet length of 197–233 m and a short, rounded tail bearing two pairs of pores and with refractive lines leading through the cuticle to a terminal depression in the protoplasm; it is differentiated from X. clavatum Heyns, 1965, X. guirani Luc & Williams, 1978, X. pyrenaicum Dalmasso, 1969, X. silvaticum Luc & Williams, 1978 and X. yapoense Luc, 1958. X. riocaquetae n.sp. is distinguished from X. macrostylum Esser, 1966. ac]19810707     

A new species of Nothotylenchus (Nematoda: Neotylenchoidea) from England

Summary Nothotylenchus adasi n.sp. is described, from a Vale of York soil. N. adasi is distinctive generally by its large size, in possessing a long spear with flange-like knobs and a long post-vulval uterine sac. ac]19791030     

Review of Ptycholaimellus Cobb (Nematoda, Chromadoridae), with descriptions of three species

Nematodes of the genus Ptycholaimellus Cobb, 1920 are unique in possessing a collar by which the head is separated from the body. The collar is raised from a groove at the border between the neck and the remainder of the body. The contents of the ventral gland cell are emptied in the groove in at least 9 out of 14 species. It is suggested that the amphids are located in the groove. Fourteen species are considered to belong to Ptycholaimellus . Two Ptycholaimellus species are described as new to science, that is, P. jacobi sp.n. and P. vincxae sp.n.; P. ponticus (Fihpjev, 1922) is redescribed. Ptycholaimellus ponticus sensu Stekhoven (1950) and Boucher (1972) from the Mediterranean off France differs from the other Ptycholaimellus species by its subcuticular ornamentation and shape of spicules, hence these specimens are regarded as belonging to a new species: Ptycholaimellus boucheri sp.n. Chromadorissa inaequibulba Aminova & Galtsova, 1978 is transferred to Ptycholai- mellus as P. inaequibulbus. Ptycholaimellus ponticus from Europe and P pandispiculatus (Hopper, 1961) from the east coast of North America are assumed to have colonized brackish waters independently.     

A new species of deepwater flathead,Bembras adenensis (Scorpaeniformes: Bembridae) from the western Indian Ocean

A new bembrid,Bembras adenensis, is described on the basis of specimens collected from the Gulf of Aden, western Indian Ocean. This species is easily distinguished fromB. japonica, the only known congener of the genus, by the following combination of characters: larger orbital diameter, longer head length, pectoral-fin with a small black blotch near tip of upper rays, 3 gill rakers on upper gill arch, 19 pectoral-fin rays, and 15 anal-fin rays (vs. smaller orbital diameter, shorter head length, pectoral-fin with several small spots forming irregular bands, 2 gill rakers on upper gill arch, usually 17 pectoral-fin rays, and 14 anal-fin rays inB. japonica).     

Spermatogenesis in a Free-Living Marine Nematode Neochromadora poecilosoma (Chromadorida,Chromadoridae) Studied Using TEM

Spermatogenesis and the structure of mature spermatozoa were studied using TEM in a free-living marine chromadorid nematode Neochromadora poecilosoma from the Sea of Japan. In spermatocytes, fibrous bodies (FB) develop; in spermatids, the synthetic apparatus lies in the residual body, while the nucleus, mitochondria, and FB are located in the main cell body (MCB). The nucleus consists of a diffuse chromatin of fibrous structure, which is not enclosed in a nuclear envelope. In the spermatid stage, the development of FB is completed, and immature spermatozoa from the proximal region of the testis do not show any structural differences from the MCB of spermatids. The mature spermatozoa are polarized cells. They attach to the uterus wall by a pseudopod filled with filaments of the cytoskeleton; in the MCB of spermatozoon, there is a nucleus surrounded by mitochondria and osmiophilic bodies. The spermatozoa of N. poecilosoma show typical ultrastructure features of sperm cells found in most studied nematodes (amoeboid nature and the absence of axoneme, acrosome, and nuclear envelope). However, no aberrant organelles characteristic of nematode spermatozoa were found throughout sperm development in N. poecilosoma and other chromadorids.     

A new genus and two new species of gobiid fishes (Perciformes) from the Chagos Archipelago,Central Indian Ocean

Synopsis A recent (1979) expedition to the Chagos Archipelago resulted in the collection of about 40 new taxa of fishes. A new genus,Trimmatom, and two new species,T. nanus andT. offucius, are described here. The new genus is characterized by having all pelvic-fin rays simple (unbranched), a scaleless body, no head pores, a wide gill opening extending anteroventrally to below the eye, and hypurals 1 and 2 fused to the complex formed by the fusion of the ural centrum and hypurals 3 and 4.T. nanuss andT. offucius are differentiated on the basis of fin ray counts and colour pattern.T. nanus is the smallest vertebrate yet to be described. Mature females with ovaries full of eggs are 8–10 mm in standard length.     

A new genus and four new species of Criconematidae (Nematoda) from the Pacific

Summary A new criconematid genus Amphisbaenema is proposed, its type being a new species, A. paradoxiger, from Western Samoa which shows an unusual combination of features in that the outer layer of the female cuticle is broken up into numerous platelets and the female head is rounded without submedian lobes, labial plates or pseudolips; the male has prominent caudal alae and juveniles have longitudinal rows of tubercles over most of the body which is covered by an outer layer of fine backwardly directed spines. Nothocriconema lamellatum (Raski & Golden, 1966) De Grisse, 1967 is transferred to this genus and a second new species, A. amicorum, from Tonga is tentatively assigned to it. Two new Nothocriconema species, N. polynesianum and N. lanxifrons, are also described. ac]19810806