Feeding Habits of Alepocephalus Rostratus (Pisces: Alepocephalidae) in the Western Mediterranean Sea

Author(s):  
M. Carrassón ◽  
J. Matallanas

The present study examines the feeding habits of Alepocephalus rostratus, the only species of the family Alepocephalidae in the Mediterranean Sea and the second most important fish species, in terms of biomass, inhabiting the deep slope of the Catalan Sea. Samples were obtained at depths between 1000–2250 m. Diet was analysed for two different size-classes (immature and mature specimens) at three different bathymetric strata during two different seasons. The feeding habits of A. rostratus included a narrow range of mobile macroplanktonic organisms (e.g. Pyrosoma atlanticum and Chelophyes appendiculata) and some material of benthic origin. Pyrosoma atlanticum was the preferred prey item in spring at 1000–1425 m, being very scarce in summer at the same depth as a consequence of its scarcity in the environment during this season. There were some ontogenic differences in the diet of A. rostratus at 1425–2250 m. Adults ingested more and larger prey than juvenile specimens. The scarcity of resources below 1200–1400 m fostered a more diversified diet, as well as passive predation of sedimented material.

2015 ◽  
Vol 96 (6) ◽  
pp. 1235-1242 ◽  
Author(s):  
Francisco Martínez-Baena ◽  
Joan Navarro ◽  
Marta Albo-Puigserver ◽  
Isabel Palomera ◽  
Rigoberto Rosas-Luis

The ommastrephid squid,Illex coindetii, is one of the most abundant cephalopods in the Mediterranean Sea and an important predator in the ecosystem. In the present study, we examined the diet habits ofI. coindetiiin the north-western Mediterranean Sea by combining two complementary approaches: stomach content and stable isotopic analyses. Specifically, we examined whether the diet differed between sizes and seasons. Stomach content results indicated that the diet ofI. coindetiiwas composed of 35 prey items including four major groups; namely the crustaceansPasiphaea sivado, Amphipods, squid of the Order Teuthida, and pelagic and mesopelagic fish. Differences were found among different ontogenetic sizes: juvenile individuals fed mainly on crustaceans (%IRI = 77.59), whereas adult individuals fed on a wider range of prey items, including the shrimpP. sivado(%IRI = 33.21), the amphipodAnchylomera blossevillei(%IRI = 0.91), the decapodPlesionikasp. (%IRI = 0.19), the carangidTrachurus trachurus(%IRI = 0.34) and some Myctophids species (%IRI = 0.21). Differences were also found between seasons in the year. In winter, crustaceans were the main prey items, whereas in summer the diversity of prey was higher, including fish, crustaceans and molluscs. Similar to the stomach contents, stable isotopic results indicated differences among sizes. δ15N values were higher in adult squids than in juveniles because they fed on prey at higher trophic levels. In conclusion, this study indicates that feeding habits ofI. coindetiivary seasonally and ontogenetically. These feeding variations may be associated with trophic competence scenarios based on size, and also with the availability and abundance of prey throughout the year.


2010 ◽  
Vol 60 (1) ◽  
pp. 209-213 ◽  
Author(s):  
Laurent Urios ◽  
Valérie Michotey ◽  
Laurent Intertaglia ◽  
Françoise Lesongeur ◽  
Philippe Lebaron

A novel Gram-negative bacteria, named CZ41_10aT, was isolated from coastal surface waters of the north-western Mediterranean Sea. Cells were motile, pleomorphic rods, 1.6 μm long and 0.7 μm wide and formed cream colonies on marine agar medium. The G+C content of the genomic DNA was 65 mol%. Phylogenetic analysis of 16S rRNA gene sequences placed the new isolate in the genus Thalassobaculum, a member of the family Rhodospirillaceae, class Alphaproteobacteria. Unlike Thalassobaculum litoreum CL-GR58T, its closest relative, strain CZ41_10aT was unable to grow anaerobically and did not exhibit nitrate reductase activity. On the basis of DNA–DNA hybridization, fatty acid content and physiological and biochemical characteristics, this isolate represents a novel species for which the name Thalassobaculum salexigens sp. nov. is proposed. The type strain is CZ41_10aT (=DSM 19539T=CIP 109064T=MOLA 84T). An emended description of the genus Thalassobaculum is also given.


2015 ◽  
Vol 96 (7) ◽  
pp. 1427-1435 ◽  
Author(s):  
S.C. García Gómez ◽  
Luis F. Carrera-Parra ◽  
Ferran Alsina Mas ◽  
Rosa Freitas ◽  
Roberto Martins

Lumbrinerids are amongst the most abundant and diverse polychaete families in worldwide continental shelves, and have received attention recently through the description of several new species and new occurrences. Herein, a total of four lumbrinerid species are firstly reported in the eastern and southern Spanish continental shelf, extending their biogeographic distribution to the western Mediterranean Sea and increasing up to 25 the number of species known in the Iberian Peninsula coasts. New insights on taxonomy, ecological and biogeographic preferences and an updated taxonomic key for Iberian coasts and surrounding areas are also provided.


Author(s):  
M. Carrassón ◽  
J. Matallanas

The feeding habits of Polyacanthonotus rissoanus, the sixth most abundant species below 1000 m on the deep slope of the Catalan Sea (western Mediterranean), were studied in the Mediterranean Sea. Samples were obtained at depths between 1000 and 2250 m. Diet was analysed for two seasons (summer and autumn) and three different bathymetric strata. The most important food items found were small epibenthic and suprabenthic crustaceans and polychaetes, and occasionally other groups such as Priapulida, Gastropoda and Foraminifera. At 1000–1425 m, the mysids were preferential prey, while in summer at all depths analysed, isopods were a dominant prey. Polychaetes have certain incidence in the diet only at 1000–1425 m, being a dominant prey in autumn. Individuals at the 1000–1425 m depth ingest larger numbers of prey of higher average sizes than those at 1425–2250 m. The scarcity of resources below 1200–1400 m resulted in diversification of diet and encouraged preying on deposited foraminiferans, molluscs or moving copepods.


Author(s):  
Theodoros Danis ◽  
Alexandros Tsakogiannis ◽  
Jon B. Kristoffersen ◽  
Daniel Golani ◽  
Dimitris Tsaparis ◽  
...  

ABSTRACTThe Tetraodontidae family encompasses several species which attract scientific interest in terms of their ecology and evolution. However, the genomic resources and especially reference assemblies are sparse for the members of the family. In this study, we focus on the silver-cheeked toadfish (Lagocephalus sceleratus) a well-known ‘invasive sprinter’ that has invaded and spread throughout the Eastern and part of the Western Mediterranean Sea from the Red Sea through the Suez Canal within a decade. We sequenced the genome of L. sceleratus using a single MinION flow cell for the main assembly, and Illumina reads for polishing the assembly. The resulted assembly consisted of 241 contigs (N50 = 11,3 Mb) with a total size of 360 Mb and yielded 98% BUSCO completeness. The high-quality genome assembly built here is expected to set the ground for future studies on this focal species’ invasive biology.


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