Volume 15 (2005-2006)

A new species Paramorea paleocenica Guzhov, sp. nov. is described from the Paleocene sediments of Ukraine. Up to now the genus Paramorea Wade, 1918 was known only from the Maastrichtian of the USA.

A new species, Neptunea alabaster sp.n. (Neogastropoda, Buccinidae) from the Bering Sea is described. This species closely related to “Neptunea lyrata” complex of species.

An experimental scallop fishing survey was carried out by F/V ’Avel Mad’ around the Falkland Islands at depths ranging from 35 m to 160 m between 5 December 2001 and 25 January 2002. Five beds of the Patagonian scallop Zygochlamys patagonica (King et Broderip, 1832) with commercial potential were found in the north-eastern and southern Falklands shelf (50°35’S–50°47’S) at depths between 130 and 145 m. All the beds were discrete, dense, and stretched stripelike along the steep shelf break. The size of beds ranged from 16 km2 to 168 km2. Average scallop CPUE by bed varied from 740 kg/h to 1170 kg/h and the total scallop catch during experimental fishery was 134.1 t. The total biomass of Patagonian scallop over all five beds was estimated to be between 18422 t and 27121 t. The age of scallops, determined using growth marks in the ligament and shell, ranged from 0+ (current year recruits; shell height less than 24 mm) to 21 years old (shell height 77 mm). Adult scallops larger than 50 mm shell height and older than 5-6 years dominated the catches on all Falklands beds. In the last two years successful recruitment was only evident on the northern beds. On average in Falklands waters strong scallop recruitment takes place once every 4 or 5 years. Estimated parameters for the von Bertalanffy growth equation ranged from 59.34 to 73.48 mm for asymptotic shell height, from 0.15 to 0.41 y-1 for the growth rate, K, and from –0.95 to –2.28 for t0. In general, scallops in Falklands waters grow rather slowly, reaching the usual commercial size (55 mm SH) at age 5-6 years old, and live to 20 years and more. Sexual maturity is reached at 35-37 mm SH and ages 2-3 years, though in coastal areas they apparently mature earlier, at 30 mm SH (2 years old).

In this study, we investigated anatomical differences between two morphs of Zonitoides nitidus with two and three stalks of spermathecal duct. An analysis of serial cross-sections of the reproductive tract distal part showed that only uppermost vaginal stalk is a genuine spermathecal duct. Other stalks are only connective-tissue strands. They are very variable in ways of their fusion with spermathecal duct, but, as a rule, inserted on vagina or connected with spermathecal duct. At the same time the lumens of the additional stalks are closed and mostly not connected with the lumen of spermathecal duct. The function of additional stalks is probably to support the complicated penial appendix and muscles of the stalks.

Spatial and seasonal distribution patterns, and size structure of the squid Okutania anonycha were studied in the northwestern Pacific Ocean and adjacent waters of the Bering Sea and Sea of Okhotsk, and a life-cycle scenario was suggested. This study used data collected during 11 research cruises of the TINRO-Centre during 1985-2004. Of 18,990 squid individuals caught in these cruises, 1861 individuals were analyzed. O. anonycha occurred in the trawl hauls in variable quantities throughout a year, and maximum catches of up to 2,800 individuals per hour trawling occurred in June. The dorsal mantle lengths ranged from 11 to 108 mm, and overall catches consisted of larval stages (16%), juveniles (54%) and feeding and maturing adults (30%). Monthly changes in size structure of the squid catches and analysis of modal class succession indicated that they might be associated with seasonal peaks of spawning. O. anonycha has a one year life cycle, and it appeared closely associated with the Western Subarctic Gyre, while adjacent waters of the Bering Sea and Sea of Okhotsk are peripheral areas of the species’ primarily oceanic range.

Based on the protoconch morphology the taxonomic position of the representatives of the genus Setia H. et A. Adams, 1852, inhabiting the Black Sea and the Sea of Azov, is revised. Comparative analysis of shell shape and ornamentation of the embryonic shell suggests that this species is Setia valvatoides Milaschewitsch, 1909. Detailed description and SEM documentation of shell morphology is provided. The type material is revised and a lectotype for S. valvatoides is designated. Some morphological characters which have been used as a basis for establishing the subfamily Setiinae Anistratenko et Starobogatov, 1994 are discussed.

A description and illustrations of the ungulinid Felaniella ohtai Kase et Miyauchi, 1996 recorded for the first time in Russian waters of the Sea of Japan (Nakhodka Bay) are given.

Widely used name Mytilus coruscus Gould, 1861, a common mussel in north-western Pacific, appeared to be a junior synonym of Mytilus unguiculatus Valenciennes, 1858. According to the article 23.9.1.1 of ICZN, the name M. coruscus is qualified as nomen protectum.