Crustacean fishery with bottom traps in an area of the southern Tyrrhenian Sea: species composition, abundance and biomass

Abstract

The north-eastern coast of Sicily is characterized by deep, steep bottoms, not easily exploitable by trawl fishery. In this area few fishermen use bottom traps to catch shrimps and Norway lobsters. Our studies were aimed at identifying the species’ composition, abundance and biomass of crustaceans exploitable by bottom traps in this area. Monthly samples over one year were obtained from two lines of 30 baited traps each, at depths between 100 and 500 m. One line was placed in an area usually exploited by this fishery; the other line was used in the unexploited deepest bottoms. Trapped specimens were counted and weighed. ANOVA test, post hoc multiple comparisons and Student’s t test were applied on abundance and biomass data, for testing differences between areas, among seasons and species. During 22 fishing days, 23 species characteristic of the bathyal mud assemblage were caught, 8 of which were not considered commercial. Plesionika edwardsii was the most important species, recorded in the whole bathymetric range investigated; Nephrops norvegicus was significantly higher in terms of biomass in the unexploited area. The discard, of slight importance, was mostly represented by the crab Liocarcinus depurator. Spring season yielded the best catches in both areas, showing the highest values for both abundance and biomass

Notes on the biology of the deep-sea crab Paramola cuvieri (Risso, 1816) (Decapoda, Homolidae) in the Canary Islands (central-east Atlantic)

“…This biomass was much higher than reported by Castriota et al (2004) in the southern Tyrrhenian Sea. In this case, the abundance oí Paramóla cuvieri off the north coast of Sicily oscillated between 13.27-29.72 g per trap (0.55-1.24 g trap"' h"'), with a similar seasonal variation (maximum during the winter and a minimum during the early summer).…”

Diversity and bathymetric distribution of decapod crustaceans attracted to baited traps from the middle slope of the northern Aegean Sea

“…There Depth range (m) 500-600 600-800 800-1000 1000-1500 S, total species; d, are only few studies with the use of traps in the Mediterranean Sea. Piccinetti et al (1995) in the Lipari Island, Castriota et al (2004) and Colloca et al (1998) in the southem Tyrrhenian Sea and also García-Rodríguez et al (2000) in the island of Alboran carried out studies with using traps. Castriota et al (2004) carried out a survey in the southem Tyrrhenian Sea, off Capo D'Orlando to identify species of cmstaceans.…”

“…Piccinetti et al (1995) in the Lipari Island, Castriota et al (2004) and Colloca et al (1998) in the southem Tyrrhenian Sea and also García-Rodríguez et al (2000) in the island of Alboran carried out studies with using traps. Castriota et al (2004) carried out a survey in the southem Tyrrhenian Sea, off Capo D'Orlando to identify species of cmstaceans. Samples were collected by baited cylindrical trap at depths ranging from 100 to 500 m. During 22 fishing days they caught 23 species of cmstaceans.…”

“…As a result of the success of these exploratory surveys, later surveys were made using these traps (González et al, 2001). Secci et al (1994) in the western Sardinia, Castriota et al (2004) and CoUoca et al (1998) in the southern Tyrrhenian Sea and García-Rodríguez et al (2000) in the island of Alboran also carried out studies with using traps in the Mediterranean Sea.…”

A new locality and host for Pseudione crenulata G.O. Sars, 1898 (Crustacea, Isopoda, Bopyridae) in the Mediterranean

“…This species was firstly misidentified and recorded as Munida rugosa (Fabricius, 1775) (Castriota et al 2004); a re-examination of the collected individuals allowed for reidentification on the basis of the diagnostic characters provided by Rice and de Saint Laurent (1986) and Noël (1992). Three of them, two males and one female, showed carapace distortion into a bulge hosting the bopyrid parasite Pseudione crenulata G.O.…”