Behavior and migration of rabbitfish Siganus fuscescens and grey seachub Kyphosus bigibbus off Nomozaki, Kyushu, tracked by biotelemetry method

Abstract

Nomozaki, where a relatively high-density seaweed patch remained, and were tracked for more than 4 months using a biotelemetry system. During the survey, signals from the S. fuscescens were recorded with high frequency in the daytime and with low frequency at night. These was a similar trend of signals from K. bigibbus, but nove was recorded at night. The total signals per day decreased when the water temperature fell to 20°C for S. fuscescens and to 16 17°C for K. bigibbus. The movement patterns of S. fuscescens and K. bigibbus may change with water temperature, however, they still stayed around the seaweed patch oŠ Nomozaki during the winter and never migrated.There is a possibility of causing serious damage to seaweed during autumn and winter, because the activity ofˆsh extended over a long period of time as a consequence of the recent rise of water temperature.

Effects of an Unusual Cold-Water Intrusion in 2008 on the Catch of Coastal Fishing Methods around Penghu Islands, Taiwan

“…Moreover, the set-net method caught significant amounts of rabbitfish in the southeastern waters of the PHI. This is in accordance with Yamaguchi et al (2006), who indicated that the gut contents of rabbitfish were fuller at 18 -23°C than at 14 -19°C; that is, cold-water intrusion positively affected the feeding activity and movement route of the rabbitfish. Speculation on the possible effect of the cold-water event on yellowfin horse mackerel is not possible because of insufficient catch data.…”

Using optimised otolith sectioning to determine the age, growth and age at sexual maturity of the herbivorous fish Kyphosus bigibbus: with a comparison to using scales

“…We expand on the findings of existing studies on the behavioural and reproductive ecology and feeding habits of K. bigibbus (Yamaguchi et al 2006(Yamaguchi et al , 2011Yamaguchi 2010) by clarifying several life history traits for this species. However, details of the early life history, population dynamics and population structure of K. bigibbus remain unclear.…”

“…The movement patterns of resident individuals demonstrate high fidelity to particular patch reefs and large home ranges, leading to large-scale landscape changes in the form of areas largely devoid of macroalgae (termed 'halos') around patch reefs (Downie et al 2013;Pillans et al 2017). On the west coast of Kyushu, Japan, K. bigibbus migrates diurnally, and its activity declines markedly when the seawater temperature decreases to ,178C (Yamaguchi et al 2006;Yamaguchi 2010). The spawning and maturation patterns of this species have been elucidated only in populations inhabiting this region.…”

Habitat use and movement of hatchery-reared F2 Mekong giant catfish in the Mae Peum reservoir, Thailand, studied by acoustic telemetry

“…Diel movements, in some cases associated with feeding, foraging, antipredator, and sheltering behavior, have been previously documented in marine demersal fish, including herbivorous fish [30][31][32], reef fish [33][34][35], ocean pelagic fish [14,36], and freshwater fish, including a catfish [22,23,37]. No predators of the relatively large ([0.6 m) study fish were present in this study.…”