Biological, Ecological and Taxonomic Characteristics of the Species Pelasgus minutus (Karaman, 1924) (Cypriniformes: Leuciscidae) from Belchishko Blato, Republic of North Macedonia

Abstract

Pelasgus minutus is an endemic Macedonian ichthyofauna species inhabiting Lake Ohrid and its basin. It is an endemic species for the Balkan Peninsula and Europe. According to the European Red list, it is in the Data De- ficient (DD) category. In the Habitats Directive, it is placed in Annex II. Kottelat and Freyhof (2007) consider that the population of P.minutus in Lake Ohrid is probably extinct. The Belchisko Blato is its last refugium. This study aims to investigate the species’ main morphological, physiological, and ecological features due to a need for more information regarding its biological characteristics. A total of 71 individuals were analysed during the ichthyological research. Sixteen meristic counts are presented, and 41 morphometric measurements are performed with percentage relationships. The gender structure indicates a stable population. The percent- age representation is 4.2% juvenile, 43.7% male and 52.1% female individuals, with age range from 0+ to 3+. The majority of the population belongs to individuals aged 2+ (47%), and the rest are as follows: 1+ (28.2%), 3+ (19.7%) and 0+ (5.1%). Sexual maturity is reached during the second year of life (1+). The most minor sexually mature male and female individuals are aged 1+. Spawning occurs during the late winter months (February- March). The average absolute fecundity is 1549 eggs, ranging from 1144 to 1549.