Crustacean Hosts of the Pedunculate Barnacle Genus Octolasmis in the Northern Gulf of Mexico

A survey of live and preserved crustaceans from the northern portion of the Gulf of Mexico was conducted to investigate the colonization habits of the barnacle genus Octolasmis. In all, three crustacean orders (Decapoda, lsopoda, and Stomatopoda) comprising 43 families, 78 genera, and 122 species were surveyed. Octolasmis barnacles were observed to infest 14 families, 20 genera, and 27 species of the orders Decapoda and Isopoda. In order of decreasing frequency, the Octolasmis species encountered were O. lowei, O. forresti, O. hoehi, and O. aymonini geryonophila. The first two were found primarily in the gill chambers, the third was found mainly on external mouthparts, and the last was found exclusively on the external mouthparts, ventral pereonal and pleonal surfaces of the isopod, Bathynomus giganteus. The decapod families Pisidae and Portunidae had the highest rates of infestation, whereas the family Galatheidae (represented by six species) did not host Octolasmis. The order Stomatopoda, represented by two families (Lysiosquillidae and Squillidae), two genera, and seven species was also not infested with Octolasmis. Statistical tests confirm that octolasmids do not randomly occupy hosts, rather they appear to select a subset, generally the larger species of crustaceans

Living in the Past: Phylogeography and Population Histories of Indo-Pacific Wrasses (Genus Halichoeres) in Shallow Lagoons versus Outer Reef Slopes

Sea level fluctuations during glacial cycles affect the distribution of shallow marine biota, exposing the continental shelf on a global scale, and displacing coral reef habitat to steep slopes on oceanic islands. In these circumstances we expect that species inhabiting lagoons should show shallow genetic architecture relative to species inhabiting more stable outer reefs. Here we test this expectation on an ocean-basin scale with four wrasses (genus Halichoeres): H. claudia (N = 194, with ocean-wide distribution) and H. ornatissimus (N = 346, a Hawaiian endemic) inhabit seaward reef slopes, whereas H. trimaculatus (N = 239) and H. margaritaceus (N = 118) inhabit lagoons and shallow habitats throughout the Pacific. Two mitochondrial markers (cytochrome oxidase I and control region) were sequenced to resolve population structure and history of each species. Haplotype and nucleotide diversity were similar among all four species. The outer reef species showed significantly less population structure, consistent with longer pelagic larval durations. Mismatch distributions and significant negative Fu’s F values indicate Pleistocene population expansion for all species, and (contrary to expectations) shallower histories in the outer slope species. We conclude that lagoonal wrasses may persist through glacial habitat disruptions, but are restricted to refugia during lower sea level stands. In contrast, outer reef slope species have homogeneous and well-connected populations through their entire ranges regardless of sea level fluctuations. These findings contradict the hypothesis that shallow species are less genetically diverse as a consequence of glacial cycles

Production Control : text and cases

xix, 413 p. ; 24 cm

Production Control

xvii, 413 p. ; 22 cm

The distribution, size, and reproduction of the pedunculate barnacle, Octolasmis m\ufclleri (Coker, 1902), on the blue crab, Callinectes sapidus (Rathburn, 1896) /

n.s. no.16 (1983