Nemertea

Dynamics of an age-structured prey with density-, and predator-dependent recruitment: the Dungeness crab and a nemertean egg predator worm.

(4) Infaunal predation examines the relative importance of excluding the nemertean, Cerebratulus lacteus, and other potential infaunal predators from both the top and bottom of EU versus excluding infauna from entering only through the top of EU (Hypothesis #4).

Low levels of movement have been documented in other hard-bottom, intertidal zone nemerteans (Roe, 1976; Caplins et al., 2012).

In the first (September 1988), I presented the three nemerteans and H.

Larval morphology may be phylogenetically relevant for nemerteans, a group for which taxonomy is mostly based on characters of adult morphology, which are few and often not unique.

Though known to be present in Bahia Culebra there are no published accounts for several groups of marine organisms, including the black corals, flatworms and nemerteans. Furthermore, conspicuos species such as marine turtles have been seem in the bay but not reported anywhere.

Since no differences were observed between roofs (cage controls) and the unmanipulated control plots and since invertebrate predators other than whelks were either naturally absent (e.g., Pisaster) or allowed in the exclusion cages (e.g., low densities of Leptasterias, nemerteans), I attribute these changes primarily to the direct and indirect effects of predation by Nucella canaliculata and N.

Bloodworm Clvmenella torquata Bamboo worm Arenicola marina Lugworm Nemerteans Cerebrattulas lacteus Milky ribbon worm Echinoderms Sclerodactyla briareus Brown sea cucumber Thyonella gemmate Green/common sea cucumber Algae Agardhiella sp.

Histological study of the secretory structures of nemerteans subjected to stress.

Kristian Fauchald and Jon Norenburg helped retrieve some of the information on large eunicids and nemerteans. Elizabeth Borda provided comments that improved the manuscript.

We do, however, have evidence that high levels of morphological homoplasy exist among a variety of groups of free-living organisms, including prokaryotes (Bremer and Bremer, 1989); fungi (Hoiland, 1987; Crisci et al., 1988); angiosperms (Crane, 1985; Freire, 1987; Bremer, 1987); opisthobranch molluscs (Gosliner and Ghiselin, 1984); amphipods (Myers, 1988); nemerteans (Sundberg, 1989); insects (Throckmorton, 1965; Saether, 1977); and vertebrates (Hecht and Edwards, 1976; Butler, 1982; Begle, 1991).

Parasites (e.g., nemerteans that are parasitic crustacean egg predators; Kuris 1993) were searched for in the embryo masses of D.

In particular, we examined brachiopods, phoronids, and nemerteans, all of which are closely related to annelids and molluscs (Halanych, 2004; Dunn et al., 2008; Kocot et al., 2010, 2011).

A group of 15 species included flatworms, nemerteans, two sipunculans, oligochaetes, two brachiopods, two echinoderms, hemichordates, a lancelet and a gobiid fish (Vargas 1989).

proportion of taxa with hard parts that are likely to fossilize) is high in 14 % (bivalve and gastropod molluscs), intermediate in 26 % (brachiopods, echinoderms, arthropods) and low in 60 % that have only soft parts (polychaetes, turbellarians, oligochaetes, hemichordates and nemerteans) (see Vargas 1987, 1988 b).