Kerbl A.,Copenhagen University |
Bekkouche N.,Copenhagen University |
Sterrer W.,Bermuda Natural History Museum |
Worsaae K.,Copenhagen University
BMC Evolutionary Biology | Year: 2015
Background: The microscopic worm group Lobatocerebridae has been regarded a 'problematicum', with the systematic relationship being highly debated until a recent phylogenomic study placed them within annelids (Curr Biol 25: 2000-2006, 2015). To date, a morphological comparison with other spiralian taxa lacks detailed information on the nervous and muscular system, which is here presented for Lobatocerebrum riegeri n. sp. based on immunohistochemistry and confocal laser scanning microscopy, supported by TEM and live observations. Results: The musculature is organized as a grid of longitudinal muscles and transverse muscular ring complexes in the trunk. The rostrum is supplied by longitudinal muscles and only a few transverse muscles. The intraepidermal central nervous system consists of a big, multi-lobed brain, nine major nerve bundles extending anteriorly into the rostrum and two lateral and one median cord extending posteriorly to the anus, connected by five commissures. The glandular epidermis has at least three types of mucus secreting glands and one type of adhesive unicellular glands. Conclusions: No exclusive "annelid characters" could be found in the neuromuscular system of Lobatocerebridae, except for perhaps the mid-ventral nerve. However, none of the observed structures disputes its position within this group. The neuromuscular and glandular system of L. riegeri n. sp. shows similarities to those of meiofaunal annelids such as Dinophilidae and Protodrilidae, yet likewise to Gnathostomulida and catenulid Platyhelminthes, all living in the restrictive interstitial environment among sand grains. It therefore suggests an extreme evolutionary plasticity of annelid nervous and muscular architecture, previously regarded as highly conservative organ systems throughout metazoan evolution. © 2015 Kerbl et al.
Olson S.L.,Smithsonian Institution |
Wingate D.B.,Bermuda Natural History Museum
Proceedings of the Biological Society of Washington | Year: 2012
Pipilo naufragus, new species, is described from Middle and Late Pleistocene to Holocene cave and pond deposits on the island of Bermuda. It is most similar to the Eastern Towhee P. erythrophthalmus but differs in having a heavier bill, more robust hindlimbs, and reduced wing and pectoral girdle, with the sternum in particular being shorter, wider, and with a much smaller carina. At least one early historical account (1610) contains a description of a large bunting-like bird that almost certainly refers to this species, which would have been exterminated by introduced pigs, rats, and cats following human settlement of Bermuda in 1612.
Sterrer W.,Bermuda Natural History Museum
Proceedings of the Biological Society of Washington | Year: 2011
Gnathostomulida, a minor phylum of microscopic marine worms, now contains about 100 described species of which many have circum-tropical distribution. Sterrer (1998) listed 50 species of Gnathostomulida from the (sub)tropical northwestern Atlantic, including Austrognathia hymanae Kirsteuer, 1970 which had been described on the basis of only one mature specimen. I here provide additional information about this species as well a description of Austrognatharia barbadensis, new species. © Biological Society of Washington.
De Putron S.J.,Bermuda Institute of Ocean Sciences |
Smith S.R.,Bermuda Natural History Museum
Bulletin of Marine Science | Year: 2011
Planula release from the scleractinian coral Porites astreoides Lamarck, 1816 at a high-latitude reef in Bermuda primarily occurred in the summer months of July and August, when the average seawater temperature for the lunar cycle preceding planulation exceeded 26.5 °C. Within the reproductive season in Bermuda, optimal planulation temperatures for P. astreoides are narrow. The release of fewer planulae was correlated with higher temperatures and there was significant variation in reproductive effort in colonies collected from sites across the 18-km wide Bermuda lagoonal seawater temperature gradient during this 2-yr study. The annual reproductive period of this species lengthens with a decline in latitude, which corresponds to a decrease in the range of annual seawater temperatures. Reproductive effort, as measured by the percentage of the population that is reproductive and number of planulae released per colony, is similar or slightly higher in Bermuda compared to conspecifics at lower latitudes. However, the shortened reproductive season results in a lower overall annual reproductive effort in Bermuda. Lunar synchrony of planula release peaked a few days before the new moon, slightly earlier than conspecifics in Florida, which peak during the new moon. Colonies from the Inner Lagoon peaked in planula release a few days earlier than those from other zones. We attribute spatial variation in lunar periodicity of planula release to differences in the timing of fertilization or planula maturation that may be influenced by environmental factors such as temperature and turbidity. © 2011 Rosenstiel School of Marine and Atmospheric Science of the University of Miami.
Wildish D.J.,Fisheries & Oceans Canada |
Smith S.R.,Bermuda Natural History Museum |
Loeza-Quintana T.,University of Guelph |
Radulovici A.E.,University of Guelph |
Adamowicz S.J.,University of Guelph
Journal of Natural History | Year: 2016
Five taxa of talitrid amphipods were found in the archipelago of Bermuda, of which three were recorded there for the first time. Four of these are supralittoral wrack generalists: Platorchestia monodi BOLD:AAB3402, (a unique Molecular Operational Taxonomic Unit according to the Barcode Index Number system), a related species recognized by molecular methods, Platorchestia platensis BOLD:AAA2949, Mexorchestia carpenteri carpenteri BOLD:AAC1491 and Tethorchestia antillensis; and one a terrestrial leaf-litter generalist: Talitroides alluaudi. A key is provided to discriminate between the formally described talitrids of Bermuda. Dispersal mechanisms from the American continent to Bermuda were considered for all taxa based on species distributions along the North American Atlantic coast and also investigated by molecular methods, using genetic population differentiation and haplotype network analysis based on the barcode region of cytochrome c oxidase subunit I gene. For P. monodi BOLD:AAB3402 the genetic results suggest that some dispersal events occurred before human colonization of Bermuda but are equivocal about the source population and therefore the direction of dispersal. Some very recent synanthropic dispersal is possible with this species. For the other two species studied genetically, P. platensis BOLD:AAA2949 and M. c. carpenteri BOLD:AAC1491, the small population samples analysed support dispersal to Bermuda from the American mainland, before human occupation of Bermuda, although the available sample size was limited for these species. The available limited direct, non-genetic evidence supports synanthropic transport for Talitroides alluaudi. Platorchestia monodi BOLD:AAB3402 is found in the same wrack habitat as P. platensis BOLD:AAA2949 on Bermuda, apparently without interbreeding. No evidence was found that driftwood specialist talitrids had become established in Bermuda. © 2016 Informa UK Limited, trading as Taylor & Francis Group