Publication Abstract

The regurgitation of stomach contents in trawl caught whiting (Merlangius merlangus L.), evidence of a predator size effect.

I.J. Staniland, P.J.B. Hart and P.J. Bromley

Sampling fish for feeding studies by trawling has the problem that regurgitation of part or all of the stomach contents can occur. Regurgitation, if undetected or ignored, can bias subsequent calculations of food consumption rates, and this has to be taken into account when converting stomach content data into estimates of feeding rates. The incidence of regurgitation of food from the stomachs of trawl-caught whiting was found to be negatively correlated with fish size. Increased musculature of the oesophageal sphincter in larger fish may enable them to resist the forced expulsion of their stomach contents to a greater extent than is the case for small whiting. Care must be taken to adjust for this bias when sampling the stomach contents fish in the field so as not to underestimate the food consumption rate in small whiting.

Reference:

 I.J. Staniland, P.J.B. Hart and P.J. Bromley* (2001) The regurgitation of stomach contents in trawl caught whiting (Merlangius merlangus L.), evidence of a predator size effect. Journal of Fish Biology, 59(5): 1430-1432