Bottom trawl selectivity on the deep-water rose shrimp Parapenaeus longirostris (Lucas, 1846)

U ovom radu simuliran je bijeg kozice (Parapenaeus longirostris) iz vreće pridnene povlačne mreže koće. Za potrebe eksperimenta uzorkovano je 135 primjeraka kozice duljine karapaksa od 9 do 32 mm. Testom propadanja se svaka uzorkovana jedinka kozice pokušala provući kroz šesnaest testnih oka veličine 52 mm i kutova otvora od 15° do 90°, laserski urezanih u plastičnu ploču debljine 5 mm. Dobiveni podatci omogućili su kreiranje selekcijske krivulje za svako testno oko. Usporedbom referentne selekcijske krivulje s krivuljama testa propadanja, identificirani su realni načini bijega kozice kroz vreću mreže. Od ukupno dvanaest testiranih načina bijega, utvrđeno je da ih je samo šest realno.This thesis describes the escapement behaviour of the deep-water rose shrimp (Parapenaeus longirostris) from the demersal trawl codend. For the experiment, 135 individuals of the deep-water rose shrimp ranging from 9 to 32 mm carapace length were collected. Using the fall-through experiments, a total of 16 meshes were tested. The meshes were 52 mm in size, with mesh opening angles ranging from 15° to 90°. The obtained results allowed creation of the selection curve for each mesh opening. By comparing the reference fall-through curves with experimentally obtained selection curve it was possible to identify 6 realistic modes of escapement utilized by the deep water rose shrimp to escape from the demersal trawl codend