A New Meiobenthic Species of Laophonte (Copepoda: Harpacticoida) from the Florida Keys

Abstract

A new meiobenthic species of Laophonte (Copepoda: Harpacticoida), described from Big Pine Key, Florida, inhabits subtidal coralline sediments near and within beds of the seagrass Thalassia testudinum. Laophonte confusa n. sp. differs from other members of the genus in its novel combination of swimming leg segmentation and setation. Based on leg setation and P5 morphology, L. confusa must be allied with the setosa species complex. L. confusa differs from other setosa species by possessing two, rather than one, setae on the 8 Ps basoendopodite. Furthermore, L. confusa is one of only a few species in Laophonte which has a seta on the inner surface of the first segment of the 9 P4 endopodite. During meiobenthic sampling of subtropical seagrass sediments in the Florida Keys (Decho, 1984; Decho et al., 1985), we encountered a new species of harpacticoid copepod. Laophonte confusa n. sp. inhabits coralline sediments within beds of Thalassia testudinum Konig and barren sand patches adjacent to such beds. The new species (designated Laophonte sp. A in Decho et al., 1985) co-occurs with 25 other copepod and eight gastrotrich species, as well as with species in 16 other taxa (Decho et al., 1985). With the recent upswing of meiobenthic ecological studies in subtropical seagrass areas (Bell et al., 1984; Thistle et al., 1984; Bell, personal communication), there has been (with the exception of Bell & Kern, 1983) a concurrent lack of taxonomic investigations, even though many undescribed species inhabit these areas. Here, we describe a new harpacticoid species and compare it with other morphologically similar species of their respective genera. MATERIALS AND METHODS Copepods were collected according to the methods of Decho et al. (1985). The nomenclature and descriptive terminology are adapted after Lang (1948, 1965). Specimen examination procedure followed that of Coull (1977). Figures were prepared with the aid of a camera lucida. The abbreviations used throughout the paper are: A,, antennule; A2, antennae; Benp, basoendopodite; Enp, endopodite; Exp, exopodite; Md, mandible; Mx, maxilla; Mxl, maxillula; Mxp, maxilliped; P,-P6, pereiopods 1-6. Length measurements do not include the antennules, rostrum, and caudal setae. We thank Drs. W. D. Hummon, Ohio University, Athens, Ohio, and J. B. J. Wells, Victoria University of Wellington, Wellington, New Zealand, for their assistance in various aspects of this work. We are further indebted to Dr. B. C. Coull, University of South Carolina, Columbia, South Carolina, for improving an earlier version of the manuscript. TRANS. AM. MICROSC. SOC., 105(1): 31-37. 1986. ? Copyright, 1986, by the American Microscopical Society, Inc. This content downloaded from 207.46.13.111 on Tue, 09 Aug 2016 05:01:57 UTC All use subject to http://about.jstor.org/terms TRANS. AM. MICROSC. SOC.