Tapas Chatterjee

Two new and one known marine water mite (Acari: Hydrachnidia: Pontarachnidae) from South-East Africa

Two new species of Litarachna are described, L. marshalli sp. n. from South Africa and L. cawthorni sp. n. from Kenya. The female of L. denhami Lohmann, 1909 is described from S. Africa. The distribution of glands and glandularia is discussed.

Report of epibiont Thecacineta calix (Ciliophora: Suctorea) on deep sea Desmodora (Nematoda) from the Andaman Sea, Indian Ocean

Suctorian epibionts Thecacineta calix attached on the cuticle of nematodes Desmodora sphaerica and D. pontica are reported here from the deep-sea hexactinellid sponge Pheronema sp. from the Andaman Sea (Indian Ocean). The epibiont T. calix is reported here for first time from the Andaman Sea.

Marine water mites (Acari: Hydrachnidia: Pontarachnidae) from Taiwan, Korea and India, with the first description of the male of Pontarachna australis Smit, 2003

Abstract The hitherto unknown male of the marine water mite Pontarachna australis Smit, 2003 (Acari: Hydrachnidia: Pontarachnidae) is described and recorded from Taiwan for the first time. Another marine water mite, Litarachna denhami (Lohmann, 1909) is recorded from India and South Korea for the first time; this species record also represents the first record of the Pontarachnidae in these countries.

Halacaridae (Acari) from Gazi Bay (Kenya): description and biogeography of three new and two known species

Three new and two known halacarid species are described from benthic and epiphytic meiofauna samples nearby five seagrass species from the east coast of Kenya (Gazi Bay). Three species belong to the genus Copidognathus (subfamily Copidognathinae). The present record of C. magnipalpus (Police, 1909) is the first one for the Kenyan coast, but also for the Western Indian Ocean. C. kenyae sp.n. is new to science because of its combination of characteristics: very stout and long rostrum going upto a quarter of palpal tibiotarsus, dorsal seta 2 on ocular plate, epimeral process absent, posterior portion of anterior dorsal plate with a few rosette pores, posterodorsal plate with two costae 2–3 pores wide, few rosette pores present on lateral side of posterodorsal plate giving indication of paracostae, tibia I with two stout, thick and short setae and one slender seta ventrally. Telofemur I with a thick ventral spine like seta. Telofemora III and IV devoid of any ventral seta, tarsi III/IV with four dorsal setae. The resemblance of this species to C. curassaviensis is discussed. C. gaziisp.n. is characterised by an anterior dorsal plate with a small frontal projection, an anterior and a big posterior areolae joined together; gland pores at the lateral margin; ocular plate with an elongated posterior tail; a crescent-shaped elevated ridge at the middle. Posterodorsal plate devoid of costae and with porose panel. Telofemora III and IV devoid of ventral seta. Porose area on telofemora I/II and tibiae I/II. Tarsi III/IV with four dorsal setae. Rhombognathus scutulatusBartsch 1983 (subfamily Rhombognathinae) is widely distributed in the Indo-Pacific region but this is the first record from the Kenyan coast. One new species of the subfamily Simognathinae was found in the Kenyan samples. Simognathus tropicalissp.n. differs from S. uniscutatus as the posterior epimeral plate is divided into two halves, which is not the case in the latter species. A pointed apical membrane in the second palpal segment could not be distinguished. An elongated ventro-distal portion of tibia I was observed. In addition to the description of the species found in Gazi Bay, an overview of the species known from the East African coast is reported.

A new species of Litarachna (Acari, Hydrachnidia, Pontarachnidae) from a Caribbean mesophotic coral ecosystem

Abstract New records of pontarachnid mites (Acari: Hydrachnidia) from the Caribbean island of Puerto Rico are presented. Litarachna lopezae sp. n., from substrata collected from Bajo de Sico, a mesophotic coral reef ecosystem in Mona Passage off Puerto Rico, is described as new to science. The new species was collected from nearly 70 m depth, the greatest depth from which pontarachnid mites have been found until now. In addition, a Litarachna sp. was also found in association with the tube of the polychaete Sabellastarte magnifica (Shaw, 1800) at the shallow waters of north Puerto Rico.

A new species of marine water mite (Acari: Hydrachnidia: Pontarachnidae) from the Red Sea

Abstract Litarachna smiti, a new species of the predominantly marine water mite family Pontarachnidae (Acari: Hydrachnidia) is described from the Red Sea (Saudi Arabia).

New records of water mites of the family Torrenticolidae (Acari, Hydrachnidia) with descriptions of two new species from Nanshih River system in Taiwan and redescription of Torrenticola ussuriensis (Sokolow, 1940) from the Russian Far East

Abstract New records of torrenticolid water mites (Acari: Hydrachnidia, Torrenticolidae) from Nanshih River, Taiwan, are presented. Two new species are described: Torrenticola nanshihensis and Torrenticola taiwanicus; the latter species is compared with Torrenticola ussuriensis (Sokolow, 1940), a poorly known species which is re-described based on a new material from the Russian Far East; Monatractides cf. circuloides (Halík, 1930)is reported for the first time for Taiwan.

Spatial distribution of the nematodes in the subtidal community of the Central West Coast of India with emphasis on Tershellingia longicaudata (Nematoda: Linhomoeidae)

Abstract Meiofaunal nematodes are among the most important components of the benthic environment. They have unusually high abundance and diversity. They are largely understudied in many parts of the world and explored very little from the Indian subcontinent, possibly due to lack of expertise. Meiofauna was investigated with emphasis on nematodes, which were the most dominant group and one species – Terschellingia longicaudata (De Man, 1907) – along the central west coast of India, stretching between Ratnagiri and Mangalore, during 2004. Maximum nematode diversity was found at the offshore location at the water depth of 35 m, while the minimum was found in the estuarine region. Nematode density was positively correlated with sediment organic matter (r= 0.73, p< 0.05). Among the 94 identified nematode species, T. longicaudata was one of the dominant species comprising >21% of nematodes and 15% of the total meiofaunal population. The species had high abundance at the stations mostly characterized by silty sediment. T. longicaudata has been hypothesized to have a global distribution and the present study, for the first time, adds to the inventory of its distribution along the central west coast of India.

A checklist of epibiotic ciliates (Peritrichia and Suctoria) on the cladoceran crustaceans

Despite the growing awareness of the ecological importance of epibiont-host associations, detailed inventories for planktonic hosts are rare. Here, we provide an updated checklist of the peritrich and suctorian epibiont ciliates (Ciliophora) on the cladocerans (Crustacea: Cladocera). Thirty-nine species of peritrich ciliates (of which 34 are assigned to species) and three species of suctorian ciliates are found to be epibionts on the Cladocera. Fifty-eight cladoceran taxa are known to be hosts of the ciliate epibionts, 33 of these hosts (57%) are planktonic. Seven taxa were determined to the level of genus. Complete species designations were geographically biased (38 of 51 species) towards European sites, suggesting poor taxonomic knowledge beyond Europe. Also, the recently discovered continental endemism of cladoceran hosts could indicate that associated ciliates are more diverse than previously appreciated.

Water mites (Acari, Hydrachnidia) from Baishih River drainage in Northern Taiwan, with description of two new species

Abstract New records of water mites (Acari: Hydrachnidia) from Baishih River drainage of north Taiwan, are presented. Twelve species are recorded, of which ten are new for Taiwan; two of them, Torrenticola projectura and Hygrobates taiwanicus are described as new for science.