Morphometric characters of the freshwater American crayfish, Orconectes limosus Raf., from the Vistula Lagoon (Poland)
Szaniawska, A.; Normant, M.; Michalowska, M.; Kaminska, A.
Oceanological and Hydrobiological Studies 34: 195-207(Suppl 1
2005
ISSN/ISBN: 1730-413X Accession: 023071507
The aim of the present study was to perform an initial characterization of the morphometric parameters of the American crayfish, Orconectes limosus, that occur in the brackish waters of the Polish coastal zone, as well as to present its range of occurrence and rate of expansion in Polish waters. The size of O. limosus occurring in the Vistula Lagoon (2-4 psu) varied from 77.0 mm to 118.0 mm (mean 95.0 plus or minus 8.0 mm). The most numerous class was comprised of specimens measuring from 90.1 to 95.0 mm; this class represented 23% of animals collected. Males and females had similar dimensions and body ratios, while the abdomen width (23.6 plus or minus 2.7 mm) of females was wider than that of males (20.3 plus or minus 2.0 mm). The males had longer and higher chelae that did females of comparable length. Individuals from Vistula Lagoon (4 psu) exhibited a larger maximum body length in comparison with those caught in the freshwater habitats (Lake Wdzydze). The relationship between carapace length and specimen dry weight is represented by the following formula: DW = 0.0072L3.05 (r = 0.69).