Factors structuring reproductive habitat suitability of Engraulis encrasicolus in the south coast of Sicily

Abstract

Egg and larval abundance, obtained from annual summer cruises carried out in the Strait of Sicily during 6 years (1997 to 2002), was used to identify the spawning and retention areas of the anchovy Engraulis encrasicolus. Larval amino acid composition was used to analyse the nutritional condition of the larvae collected during the 2002 survey. As the anchovy spawns along the south Sicilian coast, but mainly in the north-west and middle parts of the coast, the higher number and larger size larvae in the south-east end of the Sicilian coast indicated that larvae were transported by the main branch of the Atlantic-Ionian Stream and retained in the south-east end of the Sicilian coast (Cape Passero). This retention process, however, did not always favour the nutritional condition of the larvae, because the larvae were not transported to an area with a higher primary production or with a higher stability. In 2002 larval amino acid concentration was higher in the spawning areas than in those areas where the larvae were transported to, indicating a lower nutritional condition of the larvae in the nursery areas. The lack of enrichment and concentration processes, and low primary production in this area which limited body growth rate may explain the low locally reproducing anchovy population in the south coast of Sicily.

Environmental conditions influencing the larval fish assemblage during summer in the Gulf of Gabes (Tunisia: South central Mediterranean)

“…The high concentration of small pelagic larvae during the summer period in the region has been also reported by previous studies carried out in the North east of Tunisia (Koched et al, 2011;Zarrad et al, 2013) and other sectors of the Mediterranean Sea (Koutrakis et al, 2004;Isari et al, 2008). Furthermore, their preference to spawn in the deeper waters near the shelf break (Olivar et al, 2001;Cuttitta et al, 2006;Zarrad et al, 2012b) should explain the higher abundance of their larvae in the offshore stations.…”

Comparative Characterization of the Spawning Environments of European Anchovy, <I>Engraulis Encrasicolus</I>, and Round Sardinella, <I>Sardinella Aurita</I> (Actinopterygii: Clupeiformes) in the Eastern Coast of Tunisia

“…In the Mediterranean Sea, the spawning habitats of anchovy seem to be confined to shelf edges, where various kinds of enrichment process may occur (Palomera and Sabatés 1990, Palomera 1992, Olivar et al 2001, Cuttitta et al 2006. In the Bay of Biscay, anchovy select stable habitats related to river plumes, shelf edge fronts, and oceanic eddies, where increased biological production potentially occurs (Motos et al 1996).…”

Assessing population structure of European Anchovy (Engraulis encrasicolus) in the Central Mediterranean by means of traditional morphometry

“…Distance from the tip of the mouth to pelvic fin insertion [9][10][11][12][13][14][15][16][17][18][19] Distance between the pelvic fin insertion and dorsal fin [11][12][13][14][15][16][17] Distance between the last dorsal fin and first anal fin 14-16…”

“…The Strait of Sicily from an oceanographic point of view is characterized by a very complex sea circulation scheme that can strongly influence the spawning strategy and the recruitment success of many fish species and, in particular, the anchovy [8,9]. In the simplest circulation model the Modified Atlantic Water (MAW) flows eastward in the upper part of the water column, while relatively dense and salty Levantine Intermediate Water (LIW) moves westward in the lower layer [10].…”