RESUMEN
Marimermithid nematodes parasitising invertebrates are mainly found in the deep-sea environments. Several adult and juvenile specimens marimermithids of the genus Aborjinia have been found in bottom sediments and inside Polychaeta during recent cruises to the Kuril-Kamchatka trench and the Kuril Basin (the Sea of Okhotsk). New species are described based on integrative study. Aborjiniaprofundasp. nov. differs from A.eulagiscae by the location of the ventral gland cell bodies (posterior to the nerve ring vs posterior to the cardia), by the smaller body size (23-28 mm vs 103-132 mm) and shorter tail (193-263 µm vs 500-850 µm). BI and ML phylogenetic analyses based on 18S and 28S rDNA suggest that genus Aborjinia belongs to the family Leptosomatidae. Based on molecular and morphological characters the new genus Paraborjiniagen. nov. is proposed for A.corallicola. Within the family Leptosomatidae the new genus differs from all genera except Aborjinia by its endoparasitic lifestyle and hologonic ovaries. Paraborjiniagen. nov. differs from Aborjinia by the position of cephalic sensitive organs (outer labial and cephalic papillae in two separate circles vs outer labial and cephalic papillae in one circle) and by the parasitic adult (vs free-living in Aborjinia).
RESUMEN
Piipironus grandis gen. et sp. nov. is described from Piip submarine volcano, the Bering Sea. Piipironus gen. nov. shows all main characters of Thalassironinae but differs from all known ironids in the form of the amphid (spiral vs pocket-like) and the simultaneous presence of precloacal papilliform supplements and tubular postcloacal organs. Pared tubular postcloacal organs have never been described before for the family Ironidae. The combination of papilliform precloacal supplements and the pair of tubular postcloacal organs described for Piipironus grandis gen. et sp. nov. is unique among nematodes. The study of the nematofauna of the Piip submarine volcano began quite recently, and Piipironus is the second new genus of nematodes described from here from one sample of bottom sediments. This can be taken as one of the examples of the hyper-high diversity of marine nematodes.
Asunto(s)
Enóplidos , Nematodos , AnimalesRESUMEN
Gastropod molluscs such as nudibranchs are important members of deep-sea benthic ecosystems. However, data on the trophic ecology and feeding specialization of these animals are limited to date. The method of fatty acid trophic markers (FATM) was applied to determine the dietary preferences of nudibranchs off the Kuril Islands. Fatty acid (FA) compositions of Dendronotus sp., Tritonia tetraquetra, and Colga pacifica collected from deep waters were analyzed and compared with those of Aeolidia papillosa and Coryphella verrucosa from the offshore zone. The high level of FATM such as 22:5n-6 and C20 monounsaturated FAs indicated that Dendronotus sp. preys on sea anemones and/or anthoathecates hydroids similarly to that of shallow-water species A. papillosa and C. verrucosa. The high percentage of tetracosapolyenoic acids and the ratio 24:6n-3/24:5n-6 indicated that T. tetraquetra preys on soft corals such as Gersemia and/or Acanella at a depth of 250 m, but soft corals of the family Primnoidae may be the main item in the diet of T. tetraquetra at a depth of 500 m. The high content of Δ 7,13-22:2 and 22:6n-3 shows that C. pacifica can feed on bryozoans. In C. pacifica, 22:5n-6 may be synthesized intrinsically by the mollusks, whereas odd-chain and branched saturated FAs originate from associated bacteria.
RESUMEN
Oloncholaimus piipi gen. et sp. nov. is described from Piip submarine volcano, the Bering Sea. Oloncholaimus gen. nov. shows all main characters of Oncholaiminae: females monodelphic-prodelphic with antidromously reflexed ovary, three teeth with left ventrosublateral the largest, oncholaimoid type of Demanian system. New genus can be differentiated from all other genera of the family Oncholaimidae by the complex shape of dorsal and right ventrosublateral teeth with apical antler-shaped extension. Oloncholaimus piipi sp. nov. has large body (5960-7045 µm), six outer labial and four cephalic setae equal in size (5-7 µm), equal spicules (110-131 µm long) without gubernaculum, and complex precloacal supplementary organ composed of 8-9 cylindrical processes.
Asunto(s)
Enóplidos , Nematodos , Animales , FemeninoRESUMEN
Examination of material recently collected by the German-Russian deep-sea expeditions has revealed that new species occur regularly in macro- and meiobenthic samples of the North-Western (NW) Pacific. In this paper, we report three desmodorid species of the genera Desmodorella and Zalonema from the NW Pacific. They were studied and described using both scanning electron microscopy (SEM) and light microscopy. Desmodorella tenuispiculum (Allgen, 1928) was found at several locations in the Sea of Japan during the Russian-German expedition SoJaBio (Sea of Japan Biodiversity Studies) cruise of RV ''Akademik M.V. Lavrentyev'' in 2010, at water depths ranging between 515 and 1500 m. Zalonema granda sp. nov. and Z. kamchatkaensis sp. nov. are characterized by having a larger body size in comparison with other species of the genus. Zalonema kamchatkaensis sp. nov. is characterized by having a convex cephalic capsule, subcephalic setae (3-4 µm long) located in the middle and at the posterior region of the cephalic capsule, very large spiral amphidial fovea with 2.1-2.2 turns, sexual dimorphism in amphideal fovea size (larger in males, 39-45 µm, than in females, 37-43 µm). Zalonema granda sp. nov. is characterized by having a very long body (3.3-4.3 mm), curved elongate spicules (1.4-1.6 body diameter long), with blade broadening anteriorly towards the rounded capitulum, and pointed distally; weakly developed tubular gubernaculum, and absence of pre-cloacal supplements.
Asunto(s)
Nematodos/anatomía & histología , Nematodos/clasificación , Animales , Femenino , Masculino , Océano Pacífico , Especificidad de la EspecieRESUMEN
Four new Campylaimus species are described from the deep-sea sediments of the Sea of Japan at depths of about 500â3400 m. Campylaimus orientalis sp. nov. is characterized by having a body of moderate length, clearly annulated cuticle, a small rhomboid mouth opening which is displaced on the dorsal side of body, a gap between the unequal limbs of the amphid, prominent narrow longitudinal alae and cephalated spicules. Campylaimus minutus sp. nov. is characterized by having a cylindrical body, very weak annulations, amphids with a short dorsal limb (25-44% of pharynx length) and a ventral limb completely fused with lateral alae of equal width; and lateral alae extending from the base of the amphid to the tail tip. Campylaimus amphidialis sp. nov. is characterized by having the combination of a very long amphidial fovea occupying nearly the entire length of the pharynx; and a well defined boundary between the ventral amphid limb and lateral alae. The distinctive feature of Campylaimus pulcher sp. nov. is the elongated loop-shaped amphid with nearly equal parallel limbs and prominent narrow longitudinal alae; and cephalated spicules without a gubernaculum. The diagnosis of the genus Campylaimus is emended and an identification key to species, based mainly on form and length of amphidial fovea, width of lateral alae, and copulatory apparatus is given. The genus Campylaimus now includes nineteen valid species. Two species are considered as species inquirendae, mainly because of incomplete descriptions.