(full paper is archived in the Miller Library)
Title: A morphological study of a deep-sea Trachymedusa Benthocodon pedunculata (Bigelow, 1913)
Student Author(s): Chen, Esther
Faculty Advisor(s): Baxter, Charles H.
Pages: 38
Location: Final Papers Biology 175H
Date: June 1993
Abstract: Benthocodon pendunculata is a deep-sea benthopelagic medusa found abundantly in Monterey Bay and Carmel Bay, which has been virtually ignored since its original description (Bigelow, 1913). Recent observations from a remotely operated vehicle (ROV), working in the Monterey Submarine Canyon, reveal that the medusae live primarily near the deep-sea floor and may be potential predators of benthic or benthopelagic crustaceans. This study investigates the gross morphology of the medusae, tentacle types, and nematocyst types. Phase contrast microscopy and scanning electron microscopy were used to detect morphological differences between the inner and outer tentacles and also revealed two nematocyst types previously undescribed in the literature, the modified-aspirotle nematocyst and the modified-stenotele nematocyst. Gut analyses of medusae yielded copepods, amphipods, foramniferans, pycnogonid, and other unidentified organisms which show that the medusae are feeding on benthic and benthopelagic organisms. Based on the results of this study, a model of tentacular funciton in feeding medusae was generated.