Observations on the Trophic Significance of Jellyfishes in Mississippi Sound with Quantitative Data on the Associative Behavior of Small Fishes with Medusae
- 1 October 1969
- journal article
- Published by Oxford University Press (OUP) in Transactions of the American Fisheries Society
- Vol. 98 (4) , 703-712
- https://doi.org/10.1577/1548-8659(1969)98[703:oottso]2.0.co;2
Abstract
The trophic interrelationships of jellyfishes to other organisms in Mississippi Sound were investigated from March 1968 to March 1969. Ctenophores and, to a lesser extent, hydromedusae constitute the most important group of predators affecting zooplankton populations in this estuary due to: (1) extreme local abundance, and (2) voracious feeding habits. Evidence is presented that ctenophores and medusae constitute important food sources for small pelagic fishes. The commensal relationships of these fishes, Peprilus alepidotus (harvestfish) and Chloroscombrus chrysurus (bumpers) with sea nettles (Chrysaora quinquecirrha) and cabbage‐heads (Stomolophus meleagris) and Poronotus burti (Gulf butterfish) with Cyanea capillata versicolor (winter jellyfish) are discussed. These fishes and the spider crab (Libinia dubia) are commonly taken in association with medusae. Medusae provide protection and, to a greater or lesser extent, a food source for the commensals. Peprilus and Chloroscombrus probably feed on plankters stunned or killed by the nematocysts of the host jellyfish. Poronotus feed on host Cyanea and are immune to the nematocysts of this medusa. All commensal fishes other than Pronotus possessed no immunity to jellyfish toxins. Varions Crustacea (Libinia dubia, Pagurus pollicaris and Pagurus floridanus) were observed to feed on scyphomedusae. Predation of moribund Physalia physalis by shore birds and ghost crabs (Ocypode quadrata) is discussed. Data are also presented on the comparative feeding behavior of scyphomedusae, ctenophores and hydrozoans in Mississippi Sound. Portuguese men‐of‐war were found to be the only significant predator of pelagic fishes. Sea nettles and Cyanea were found to feed mainly on ctenophores whereas cabbageheads feed on microzooplankton and sea wasps feed on microcrustacea and larval crustaceans.This publication has 0 references indexed in Scilit: