Feeding habits of the yellowtail flounder and production of its invertebrate prey on Georges Bank
type: CreativeWork
description: As part of the Georges Bank Benthic Infauna Monitoring Program, size-frequency analysis was used to study the life history and production of three benthic amphipod species: Ampelisca agassizi, Unciola inermis and Ericthonius fasciatus. Abundant over large areas of Georges Bank, these amphipods are important prey of yellowtail flounder. From benthic grab samples collected quarterly during 1981 to 1983, over 200 individuals of each species were measured for each sampling date. The computer program NORMSEP separated the length-frequency distributions into cohorts. Growth and mortality rates were determined by following cohorts through time; production was calculated as the sum of growth increments. Differences in the population dynamics of the three species were exemplified by annual production-to-biomass ratios (P/B). E. fasciatus had the highest P/B (2.8 to 4.1), followed by U. inermis (1.3 to 2.7) and A. agassizi (1.3 to 1.4). These results, the first direct production estimates for benthic macrofaunal species on Georges Bank, are compared to production estimates for other marine amphipod species. Amphipod production rates on Georges Bank are as high as production rates of related near-shore species with similar life-spans. The Northeast Fisheries Center sampled yellowtail flounder stomachs at three sites on four quarterly dates from August 1982 to May 1983. As closely as possible, stomach sampling coincided with the dates and locations of benthic monitoring to enable direct comparison between ingested and available food. Stomach contents were sorted and weighed and important prey species were measured. Yellowtail flounder feed mainly on benthic macrofauna; amphipods and polychaetes are the most important prey groups. Although the diet composition varied among stations and dates, in each case a few prey species constituted the bulk of the diet. Selection indices were calculated to compare the species composition of the stomach contents to that of the benthic macrofa…
abstract: As part of the Georges Bank Benthic Infauna Monitoring Program, size-frequency analysis was used to study the life history and production of three benthic amphipod species: Ampelisca agassizi, Unciola inermis and Ericthonius fasciatus. Abundant over large areas of Georges Bank, these amphipods are important prey of yellowtail flounder. From benthic grab samples collected quarterly during 1981 to 1983, over 200 individuals of each species were measured for each sampling date. The computer program NORMSEP separated the length-frequency distributions into cohorts. Growth and mortality rates were determined by following cohorts through time; production was calculated as the sum of growth increments. Differences in the population dynamics of the three species were exemplified by annual production-to-biomass ratios (P/B). E. fasciatus had the highest P/B (2.8 to 4.1), followed by U. inermis (1.3 to 2.7) and A. agassizi (1.3 to 1.4). These results, the first direct production estimates for benthic macrofaunal species on Georges Bank, are compared to production estimates for other marine amphipod species. Amphipod production rates on Georges Bank are as high as production rates of related near-shore species with similar life-spans. The Northeast Fisheries Center sampled yellowtail flounder stomachs at three sites on four quarterly dates from August 1982 to May 1983. As closely as possible, stomach sampling coincided with the dates and locations of benthic monitoring to enable direct comparison between ingested and available food. Stomach contents were sorted and weighed and important prey species were measured. Yellowtail flounder feed mainly on benthic macrofauna; amphipods and polychaetes are the most important prey groups. Although the diet composition varied among stations and dates, in each case a few prey species constituted the bulk of the diet. Selection indices were calculated to compare the species composition of the stomach contents to that of the benthic macrofa…
author: Collie, Jeremy S.
language: en_US
keywords: Flatfishes, Fishes, Feeding and feeds, Gloria Michelle (Ship) Cruise, Wieczno (Ship) Cruise
date published: 1985-09
date modified: 2026-07-27T22:05:08Z
provider: Woods Hole Oceanographic Institute
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Massachusetts Institute of Technology and Woods Hole Oceanographic Institution

PropertyValue
property ID: Handle
value: https://hdl.handle.net/1912/3151

PropertyValue
property ID: DOI
value: 10.1575/1912/3151