Temporal change in foraging behaviour of the fish Coryphaenoides (Nematonurus) yaquinae in the central North Pacific

Abstract

Deep-sea grenadier fish Coryphaenoides (Nematonurus) yaquinae were attracted to a baited free-fall video camera and tracklng vehicle dunng 10 deployments in the central North Pacific (31°N, 159" W) at a depth of 5800 m. The mean time of arrival of the first fish was 31.0 min after landing on the sea floor. The mean number of fish within camera view increased to a peak of 5.25 at 90 min after landing and decreased thereafter The mitial arrival rate was 0.06 fish mm-', and mean fish staying time was 122 min The staying time was much shorter than in previous work at this site, suggesting a change in food supply with time of year Grenadiers were tracked using ingestible acoustic transmitters. The mean time until transmitter ingestion after the bait landed was 85.1 min. Fish that swallowed transmitters dispersed at radial rates of l to 20 cm S -' , and all had departed to a range of > 1000 m by 13 h after landlng. Movements to an altitude of > 15 m were recorded for 60 % of fish tracked and occupied 12.9 "10 of total tracking time. Bottom current speeds were between < 1 and 9 cm S-' with a tidal rhythmicity

Biology and ecology of Nezumia liolepis and N. stelgidolepis from the west coast of North America

“…Little is known of the life history of macrourids from the eastern North Pacific. A few common species of Coryphaenoides and Albatrossia pectoralis (Gilbert) have been studied (Novikov, 1970;Pearcy & Ambler, 1974;Stein & Pearcy, 1982;Wilson, 1982Wilson, , 1988Armstrong et al, 1991;Andrews et al, 1999;Buckley et al, 1999;Drazen et al, 2000) and scant ecological or biological information is available on eastern North Pacific species of Nezumia.…”

A seasonal analysis of the nutritional condition of deep-sea macrourid fishes in the north-east Pacific

“…Instead, seasonal variation in nutritional condition would result from changes in feeding activity, metabolism and growth. Seasonal variation in foraging behaviour has been described for both C. armatus (Priede et al, 1994) and C. yaquinae (Armstrong et al, 1991) and a pronounced seasonal input of organic matter to the deep-sea community is well documented at Station M Smith & Druffel, 1998). These investigators found that fishes had higher swimming speeds and shorter staying times at bait stations in autumn after the annual deposition of phytodetritus to the seabed.…”

“…Knowledge of seasonal cycles in their feeding activity is important for understanding the energetics of the species as well as defining their relationship with the rest of the community. Armstrong et al (1991) and Priede et al (1994) have shown that there is a seasonal variation in foraging behaviour (swimming speeds and staying times at artificial bait stations) for the macrourids Coryphaenoides yaquinae Iwamoto & Stein and Coryphaenoides armatus Hector in the central North Pacific and eastern North Pacific respectively. While these fishes are not eating phytodetritus, their prey populations could vary in abundance, activity or availability in response to phytodetritus input.…”

Co-ordinator

“…Grenadiers (Coryphaenoides yaquinae, C. armatus), deep sea eels (Synaphobranchus bathybius) and the deep sea gadoid (Antimora rostrata) have all been successfully tagged with acoustic tags after ingestion of bait hung beneath the cameras of a deep-sea lander (e.g. Armstrong et al, 1991Armstrong et al, , 1992aBagley et al, 1994;Priede et al, 1990Priede et al, , 1994aCollins et al, 1998).…”