Spatial segregation of two common Gobius species (Teleostei: Gobiidae) in the northern Adriatic Sea

• Published in: Marine ecology (Berlin, West) West), 2005-01, Vol.26 (2), p.121-129
• Main Authors: Herler, J, Patzner, R A
• Format: Article
• Language: English
• Subjects: Fallax; Gobiidae; Gobius; Gobius auratus; Gobius fallax; Marine; Teleostei
• ISSN: 0173-9565; 1439-0485
• DOI: 10.111/j.1439-0485.2005.00045.x

The habitat characteristics and spatial segregation of the two common gobies Gobius fallax Sarato, 1889 and Gobius auratus Risso, 1810 were investigated by fish frequency and abundance estimates through visual counts in the northern Adriatic Sea. The latter species is represented by a recently described, unusual colour morph in the northern Adriatic Sea. Gobius fallax was observed at five of the nine locations examined and its abundance did not differ between two of three transect locations at Piran (Slovenia) and at the western coast of Cres (Kvarner region, Croatia). Gobius auratus was not found in the Gulf of Trieste but was present at several Kvarner locations, and co-occurred with G. fallax at one location at Cres. Both inhabit rocky substrates but they show different preferences for substrate inclinations and bathymetric segregation. Gobius fallax was most frequent between 2 and 8 m depth and was most abundant on substrate inclining less than 30 degree . Its highest abundance over entire transects was 0.3 indiv. times m super(-2) but within certain transect sections this increased to 1.25 indiv. times m super(-2). Gobius auratu attained its highest abundance in depths below 8 m and at substrate inclinations between 30 and 90 degree . This species attained its highest values at the western coast of Cres, where it reached a maximum of 1.5 indiv. times m super(-2) over entire transects but even up to 3.0 indiv. times m super(-2) in certain transect sections. At Krk, the maximum abundance over entire transects was only 0.3 indiv. times m super(-2).