Search

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.dsr.2005.06.013 Byline: T. Madurell (a), J.E. Cartes (b) Keywords: Daily ration; Energy intake; Demersal fish; Eastern Mediterranean Abstract: Daily food consumption of the eight dominant demersal fish species of the bathyal eastern Ionian Sea were determined from field data on four seasonal cruises (April 1999, July August 1999, November 1999 and February 2000). Daily ration (DR) estimates ranged from 0.198 to 4.273% WW/WW. Overall, DR estimates were independent of the model used, and they were comparable to the daily consumption of other deep-sea fauna (e.g. fish and crustaceans). Both sharks studied (Galeus melastomus and Etmopterus spinax) exhibited the highest values of DRs, together with the macrourid Coelorhynchus coelorhynchus in August. Among osteichthyes, DR estimates were related (in a multi-linear regression model) to the nature of their diet (i.e. their trophic level deduced from [delta].sup.15N isotopic composition, the mean number of prey and trophic diversity). Thus, species feeding at a lower trophic level, ingesting a large number of prey items and with a very diversified diet had higher DR than species from higher trophic level and feeding fewer prey items. By season, the DR of species feeding mainly on mesopelagic prey (Hoplostethus mediterraneus and Helicolenus dactylopterus) were higher in summer, while DR for benthos/suprabenthos feeders (i.e. C. coelorhynchus and Nezumia sclerorhynchus) were higher in spring. Higher food consumption coincides with maximum food availability, both among mesopelagic feeders (higher availability of euphausiids, Pasiphaea sivado and Sergestes arcticus in summer) and among Macrouridae (higher suprabenthos densities in spring). In a tentative estimate the energy intake deduced from diet (i.e. mean energy value of food ingested) was constant in all seasons for each species studied. Results for the energy intake also indicate higher energy intake in the diet of mesopelagic feeders than in the diet of benthic feeders. Overall results are discussed in relation to the deep-sea ecosystem structure and functioning. Author Affiliation: (a) Hellenic Centre for Marine Research, Aghios Kosmas, Hellinikon, 6604 Athens, Greece (b) Institut de Ciencies del Mar (CSIC), Pg. Maritim de la Barceloneta, 37-49, 08003 Barcelona, Spain Article History: Received 12 April 2004; Revised 14 March 2005; Accepted 28 June 2005

Data on the diet, feeding habits and daily rations of Hoplostethus mediterraneus Cuvier, 1829 in the bathyal eastern Ionian Sea (Mediterranean Sea) are presented. A total of 430 specimens collected by bottom trawls at depths ranging from 473 to 603 m during four 24-h day-night sampling cycles covering the four annual seasons was examined. H. mediterraneus diet consisted of pelagic and vagile epibenthic prey, mainly crustaceans, and was dominated by benthopelagic natantian decapods (83.35% IRI, index of relative importance). Seasonal changes in diet were apparent and related to seasonal fluctuations in suprabenthic and zooplanktonic prey in the environment. Diel patterns in stomach fullness and trends in diel feeding cycles are discussed in relation to the vertical migratory movements of available prey (i.e. suprabenthos and zooplankton). Daily-ration estimates were determined by evacuation-rate models and ranged from 0.143% to 0.397% WW/WW. Overall, dailyration estimates were within the range of the daily consumption of other deep-sea fish. Deduced from diet contents, we found a constant gross energy intake (305-316 kcal [g.sup.-1]) during all seasons. As a possible response to the reproductive peak of mature females observed in summer, H. mediterraneus increases its food consumption, which, in turn, is coupled with an increase in food availability., Introduction The Mediterranean slimehead Hoplostethus mediterraneus is a common demersal fish occurring in the northeastern Atlantic and in the Mediterranean, and is also found in the Indian and South Pacific [...]

Submarine canyons are known as one of the seafloor morphological features where living cold-water coral (CWC) communities develop in the Mediterranean Sea. We investigated the CWC community of the two westernmost submarine canyons of the Gulf of Lions canyon system: the Cap de Creus Canyon (CCC) and Lacaze Duthiers Canyon (LDC). Coral associations have been studied through video material recorded by means of a manned submersible and a remotely operated vehicle. Video transects have been conducted and analyzed in order to obtain information on (1) coral bathymetric distribution and density patterns, (2) size structure of coral populations, and (3) coral colony orientation with respect to the substrate. Madrepora oculata was the most abundant CWC in both canyons, while Lophelia pertusa and Dendrophyllia cornigera mostly occurred as isolated colonies or in small patches. An important exception was detected in a vertical cliff in LDC where a large Lophelia pertusa framework was documented. This is the first record of such an extended L. pertusa framework in the Mediterranean Sea. In both canyons coral populations were dominated by medium and large colonies, but the frequent presence of small-sized colonies also indicate active recruitment. The predominant coral orientation with respect to the substrate (90° and 135°) is probably driven by the current regime as well as by the sediment load transported by the current flows. In general no clear differences were observed between the CWC populations from CCC and LDC, despite large differences in particulate matter between canyons. [ABSTRACT FROM AUTHOR]

Data on the diet, feeding habits and daily rations ofHoplostethus mediterraneusCuvier, 1829 in the bathyal eastern Ionian Sea (Mediterranean Sea) are presented. A total of 430 specimens collected by bottom trawls at depths ranging from 473 to 603 m during four 24-h day-night sampling cycles covering the four annual seasons was examined.H.mediterraneusdiet consisted of pelagic and vagile epibenthic prey, mainly crustaceans, and was dominated by benthopelagic natantian decapods (83.35% IRI, index of relative importance). Seasonal changes in diet were apparent and related to seasonal fluctuations in suprabenthic and zooplanktonic prey in the environment. Diel patterns in stomach fullness and trends in diel feeding cycles are discussed in relation to the vertical migratory movements of available prey (i.e. suprabenthos and zooplankton). Daily-ration estimates were determined by evacuation-rate models and ranged from 0.143% to 0.397% WW/WW. Overall, daily-ration estimates were within the range of the daily consumption of other deep-sea fish. Deduced from diet contents, we found a constant gross energy intake (305-316 kcal g-1) during all seasons. As a possible response to the reproductive peak of mature females observed in summer,H.mediterraneusincreases its food consumption, which, in turn, is coupled with an increase in food availability. [ABSTRACT FROM AUTHOR]

Phylogenetic relationships and the timing of evolutionary events are essential for understanding evolution on longer time scales. Cheilostome bryozoans are a group of ubiquitous, species-rich, marine colonial organisms with an excellent fossil record but lack phylogenetic relationships inferred from molecular data. We present genome-skimmed data for 395 cheilostomes and combine these with 315 published sequences to infer relationships and the timing of key events among c. 500 cheilostome species. We find that named cheilostome genera and species are phylogenetically coherent, rendering fossil or contemporary specimens readily delimited using only skeletal morphology. Our phylogeny shows that parental care in the form of brooding evolved several times independently but was never lost in cheilostomes. Our fossil calibration, robust to varied assumptions, indicates that the cheilostome lineage and parental care therein could have Paleozoic origins, much older than the first known fossil record of cheilostomes in the Late Jurassic.