Abstract
During an interstitial faunal survey along the south-west coast of Kerala, India, gastrotrich fauna were found in abundance. Together with species of the genera Xenotrichula, Halichaetonotus and Tetranchyroderma, were present several undescribed thaumastodermatid gastrotrichs belonging to the buccal palp bearing genus Pseudostomella. Adults of the new species are characterized by the following traits: total body length of about 300 μ m; cuticular armature made up of medium sized pentancres covering the entire dorsolateral surface; pre-buccal, grasping palps bearing five, large papillae dorsally and 4-6 smaller papillae ventrally; adhesive apparatus made up of six anterior, 22-24 ventrolateral, two dorsolateral and six posterior adhesive tubes; caudal organ pear-shaped; frontal organ spherical. Pseudostomella cheraensis sp. nov. is the fourth taxon of the genus known from India; however, all the previous species reported hitherto from India have tetrancres instead of pentancres.References
Brusca, R.C. & Brusca, G.J. ( 1990) Invertebrates. Sunderland, Massachussetts: Sinauer Publication), 922 pp.
Balsamo, M., Guidi, L., Pierboni, L., Marotta, R., Todaro, M.A. & Ferraguti, M. (2007) Living without mitochondria: spermatozoa and spermatogenesis in two species of Urodasys (Gastrotricha, Macrodasyida) from dysoxic sediments. Invertebrate Biology. 126, 1–9.
Clausen, C. (2000) Gastrotricha Macrodasyida from the Tromso region, Norway. Sarsia, 85, 357–384.
Causen, C. (2004) Gastrotricha from the Faroe Bank. Sarsia, 89, 423–458.
Hochberg, R. (2002) Two new species of Pseudostomella (Gastrotricha: Macrodasyida) with scaled triancres from the east coast of Australia. New Zealand Journal of Marine and Freshwater Research, 36, 571–579.
Hummon, W.D., Todaro, M.A. & Tongiorgi, P. (1993) Italian marine Gastrotricha: II. One new genus and 10 new species of Macrodasyida. Bollettino di Zoologia, 60, 109–127.
Lee, J.M. & Chang, C.Y. (2002) Pseudostomella Gastrotrichs (Macrodasyida, Thaumastodermatidae) from South Korea, with a brief Review of the genus. Korean Journal of Biological Science, 6, 207–213.
Leasi, F., Virno-Lamberti, C. & Todaro, M. A. (2006) First record of Musellifer profundus (Gastrotricha) in the Italian seas. Biologia Marina Mediterranea, 13, 190–191.
Naidu, K.V. & Rao, G.C. ( 2004) Gastrotricha. Fauna of India and the adjacent countries. Zoological Survey of India, Kolkata, pp 1–169.
Pfannkuche, O. & Thiel, H. (1988) Sample processing. In: Higgins, R. P. & Thiel, H. (Eds.), Introduction to the study of meiofauna. Washington, DC: Smithsonian Institution Press, pp. 134–145.
Rao, G. C. (1970) Three new interstitial gastrotrichs from Andhra coast, India. Cahiers de Biologie Marine, 11, 109–120.
Rao, G. C. (1993) Little meiofauna of little Andaman. Records of Zoological Survey of India, 155, 1–120.
Renaud-Mornant, J. (1967) Pseudostomella malayica n. sp., Gastrotriche nouveau de la cote orientale de Malaise. Bulletin du Museum National d’Historie Naturelle, 39, 209–212.
Ruppert, E.E. (1970) On Psuedostomella Swedmark 1956 with descriptions of P. plumose nov. spec., P. cataphracta nov. spec., and a form of P. roscovita Swedmark 1956 from the West Atlantic coast. Cahiers de Biologie Marine, 11, 121–143.
Ruppert, E.E. (1991) Gastrotricha. In: Harrison, F. W. & Ruppert, E.E. (Eds.), Microscopic Anatomy of Invertebrates. 4: Aschelminthes. John Wiley & Sons, New York, pp. 41–109.
Ruppert, E.E. & Barnes, R.D. (1994) Invertebrate Zoology 6th ed. (Fort Worth, Texas: Saunders College Publishing), 1054 pp.
Swedmark, B. (1956) Nouveaux Gastrotriches Macrodasyoides de la region de Roscoff. Archives de Zoologie Experimentale et Generale, 94, 43–57.
Todaro, M.A. (1998) Meiofauna from the Meloria Shoals: Gastrotricha, biodiversity and seasonal dynamics, Biologia Marina Mediterranea, 5, 587–590.
Todaro, M.A. & Rocha, C. .F. (2004) Diversity and distribution of marine Gastrotricha along the northern beaches of the state of Sao Paulo (Brazil), with description of a new species of Macrodasys (Macrodasyida, Macrodasyidae). Journal of Natural History, 38, 1605–1634.
Todaro, M.A., Telford, M.J., Lockyer, A.E. & Littlewood, D.T.J. (2006a) Interrelationships of the Gastrotricha and their place among the Metazoa inferred from 18S rRNA genes. Zoologica Scripta, 35, 251–259.
Todaro, M.A., Leasi, F., Bizzarri, N. & Tongiorgi, P. (2006b) Meiofauna densities and gastrotrich community composition in a Mediterranean sea cave. Marine Biology, 149, 1079–1091.
Todaro, M.A., Guidi, L., Leasi, F. & Tongiorgi, P. (2006c) Morphology of Xenodasys (Gastrotricha): the first species from the Mediterranean Sea and the establishment of Chordodasiopsis gen. nov. and Xenodasyidae fam. nov. Journal of the Marine Biological Association of the United Kingdom, 86, 1005–1015.
Valbonesi, A. & Luporini, P. (1984) Researches on the coast of Somalia. Gastrotricha, Macrodasyoidea. Monitore Zoologico Italiano, Supplemento, 1, 1–24.