Browsing Irish Fisheries Bulletin by Subject "Spawning"
Now showing items 1-2 of 2
Spawning Trout in Eastern ConnemaraConcentrations totalling 299 trout from nine spawning sites in eastern Connemara in 1981 were examined to elucidate the spawning biology of these stocks. Sea trout made up the majority. Brown liveried fish predominated among migratory males (75%) but were few among females (2.5%). Males were of younger sea and river age than females and the ratio of females to males was lowest among the younger age categories. Scars and marks were evenly distributed between the sexes and 51% of females showed signs of being spent. Spawning Connemara sea trout were similar to spawning Cummeragh, Co. Kerry, sea trout in a number of, respects as for example their length at age but the spawning behaviour of fish in the two places differed considerably: the density of spawning fish was greater in the Cummeragh than in Connemara where immature trout occurred in the vicinity of the redds. The ratio of females to males was lower in Connemara than in the Cummeragh and males appeared to be more heavily marked in Connemara. The relevance of these observations to some known genetic characteristics of the stocks is briefly discussed.
Spawning trout Salmo trutta L. populations in the Cummeragh System, Co. KerryConcentrations totalling more than 300 spawning trout from five sites at three parts of the Cummeragh system were examined in 1980. The majority of the fish were sea trout but some brown trout and precocious males occurred at every site. Of the various physical characteristics of the sites, numbers of fish displayed the most consistent relationship with the volume of water in the pools where they occurred. Trout ranged from 22cm to 68cm fork length and maiden fish of two sea summers comprised the majority. Brown trout matured at a smaller size and younger age than sea trout. Males matured before females and older smolts before younger. Females outnumbered males in the entire collections although there were differences in this and other characteristics of the fish from one site to another, a result it is thought of the timing of sampling. The majority of male sea trout had a brown livery and more female than male trout displayed scars on the body behind the dorsal fin.