Learning Effect on Predator Avoidance in Hatchery-reared Juveniles of the Red Sea Bream, Pagrus major.

Accession number;01A0744142
Title;Learning Effect on Predator Avoidance in Hatchery-reared Juveniles of the Red Sea Bream, Pagrus major.
Author; FUJIKAWA YUJI (Shimanekennaisuimensuishi) SASAKI TADASHI (Shimanekensuishi Kashimaasamibunjo)
Journal Title;Suisan Zoshoku
Journal Code:Y0285A
ISSN:0371-4217
VOL.49;NO.2;PAGE.151-156(2001)
Figure&Table&Reference;FIG.1, TBL.5, REF.14
Pub. Country;Japan
Language;Japanese
Abstract;Learning effect on predator avoidance was examined in a tank where hatchery-reared juveniles of red sea bream Pagrus major were exposed to the predation of the devil stinger, Inimicus japonicus. The growth of the learner may weaken the effect in this case. Younger, or smaller(56mm in mean total length) juveniles were observed to apparently resist the predation pressure, when they had experienced even once such predation pressure. Interesting evidence suggests that the learning effect may be kept there at least for 24 hours. On the other hand, larger(81-100mm in mean total length) fish had not exercise such learning ability as do the younger group of fish. As far as our observation goes, the availability of red sea bream seeds should be improved by exposing them to any rate of predation pressure in prior to stock them in environment with mortal danger of predators. (author abst.)