The reproductive cycle of a local population the aspidochirote Holothuria tubulosa in Kaštela Bay (Adriatic Sea) was analysed from July 1994 to August 1995 by histological examination and observations of macroscopic features of the gonads. Five gonadal stages were described: recovery stage, growing stage, mature stage, spawning stage, and post-spawning stage. The distinguishing features used to describe gonad stages in both sexes included the main features of reproductive cells and gonad wall. The reproductive cycle showed a clear annual pattern and was synchronous in both sexes. Spawning occurred during the warm season, from July to September, when the surface water temperature ranged from about 22°C to 26°C. From October to January individuals were in resting phase and had no gonads. In both sexes, variations in maturity indices were related to the seasonal changes in temperature.

Data on the distribution and abundance of the Atlantic mud shrimp, Solenocera membranacea in the northern and central Adriatic Sea were collected by bottom trawl during 11 cruises of the "Pipeta" Expedition in the Adriatic Sea from 1985 to 1994. The expedition sampled approximately 59,000 km 2 of the continental shelf at predetermined permanent stations over different sediment types at depths of 10 to 430 m. The shrimp were found in depths of 55 to 289 m. The highest mean abundance was observed in the 50 to 100 m depth layer and from "relict" sand (sediment settled during the last glacial, and that was resedimented during the Holocene transgression) and clayey "relict" sand sediments. RÉSUMÉDes données sur la distribution et l'abondance de la crevette atlantique des fonds vaseux, Solenocera membranacea dans les zones nord et centrale de la mer Adriatique ont été collectées par chalutage au cours de 11 croisières de l'expédition "Pipeta" dans la mer Adriatique de 1985 à 1994. L'expédition a échantillonné approximativement 59.000 km 2 du plateau continental à des stations pré-déteminées sur différents types de sédiments, à des profondeurs de 10 à 430 m. Les crevettes ont été trouvées à des profondeurs de 55 à 289 m. L'abondance la plus élevée a été observée à des profondeurs de 50 à 100 m et sur des fonds de sable "reliques" (sédiments déposés durant la dernière glaciation et re-sédimentés durant la transgression holocène) et de sables argileux sédimenteux "reliques".

Very valuable papers concerning malacology of the Adriatic Sea deal, for the most part, with the systematics, whereas there is a substantial number of papers with very scarce information on the ecology of individual species. Since I intended to provide some more comprehensive data on individual species, rather complex bionomic and biocoenological research was undertaken aiming to study the taxonomy and the ecology of the Prosobranchiata group. Present research covered different biotopes of the northern, middle and southern Adriatic, both in the shallow coastal and deeper open littoral, and hard and mobile bottoms. Material was collected in two ways: 1) Scuba diving or direct collection and observations; and 2) an indirect method of collection of samples by Petersen grab, dredge and trawl. Throughout years of investigations of the coastal and open Adriatic, the species Cymatium corrugatum has been recorded only in the vicinity of the Vis and Hvar islands, at 60 and 80 m depths. It was found in the biocoenosis of detritic bottoms of the open sea and biocoenosis of coastal detritic bottoms. Cymatium corrugatum is a new species for the Adriatic and therefore it should be included in the register of the Gastropod fauna of the Adriatic Sea. 0 Elsevier, Paris / Ifremer / Cnrs / Ird Cymatium corrugatum / Gastropoda I new species / Adriatic Sea Rt%umC-Cymatim corrugalum (Lamarck 1816) gastbropode prosobranche. Une esp&ce nouvelle en Adriatique. Les travaux sur la malacologie de 1'Adriatique concement, en general, I'aspect taxonomique, tandis que ceux qui traitent de l'ecologie des espbces individuelles, n'apportent que peu d'informations. Pour amtliorer la connaissance des especes individuelles, des recherches complexes ont ete entreprises sur la bionomie et la biocoenologie du groupe des Prosobranches, paralltlement aux etudes taxonomiques et dcologiques. Les recherches ont couvert differents biotopes de 1'Adriatique septentrionale, centrale et meridionale, a la c&e et au large, sur des fonds solides et mobiles. Deux methodes de prelevement ont etC utilisees : 1) observation et echantillonnage directs par plongeurs en scaphandre autonome et 2) Cchantillonnage indirect par benne Petersen, dragage et chalutage. Au cours de plusieurs an&es, I'esptce Cymatium corrugatum n'a ete signalee que pres des iles Vis et Hvar, entre 60 et 80 m de profondeur, dans les biocoenoses des fonds detritiques &tiers et dans ceux du large. Cymatium corrugatum, espece nouvelle pour l'Adriatique, devrait $tre inseree dans l'inventaire de la faune des gasteropodes adriatiques. 0 Elsevier,