James A. Blake

Reproduction and larval development of the spioniform Polychaeta with application to systematics and phylogeny

The reproduction and larval development of spioniform polychaetes are reviewed. Asexual reproduction is relatively rare, being reported for only eight species belonging to the genus Pygospio and some polydorids. Both architomy and paratomy are known, with the latter limited to small species of Pseudopolydora (sometimes referred to Polydorella) and one species of Polydora. Architomy is often the primary form of reproduction in Pygospio elegans and contributes to the maintenance of large populations. Three types of eggs (thin egg envelopes, thick egg envelopes, smooth or reticulated, and thick egg envelopes, honeycombed), two types of oogenesis (extraovarian and intraovarian), and two types of sperm (ect-aquasperm and introsperm) occur in spioniforms. Egg and sperm type are restricted to specific clades. Eggs with thickened egg envelopes appear to be limited to spioniforms, whereas the thin egg envelope found in some spionids occurs in other polychaete families, suggesting that thin egg envelopes are plesiomorphic for spionids. Spermatophores occur in the spionid subfamily Spioninae and are formed in the male nephridia. Spioniforms exhibit a diversity of reproductive and larval patterns including broadcast spawning, external egg masses, brooding in capsules in tubes of females and brooding on the bodies of females. Poecilogony is unusually common in the Spionidae. A phylogenetic analysis demonstrates that reproductive and larval characters, when used in combination with selected adult characters, provide a more complete database to evaluate systematic and phylogenetic relationships than only adult morphology. Preliminary results of parsimony suggest that the Spionidae are paraphyletic and that its definition and the status of related spioniform polychaetes needs to be reassessed with regard to family level classification.

Dorvilleidae (Annelida:Polychaeta) from the U.S. Atlantic slope and rise. Description of two new genera and 14 new species, with a generic revision of Ophryotrocha

The present paper contains descriptions of 14 new species of dorvilleid polychaetes that are part of a highly diverse benthic infauna sampled on the U.S. Atlantic slope and rise between the Canadian border and South Carolina. Quantitative samples were taken with a Hessler‐Sandia box core during 18 cruises between 1983 and 1987. Samples were sieved through screens having a mesh opening of 300 μ. The newly described species belong to the genera Ophryorrocha. Exallopus. Parophryotrocha and two new genera, Pseudophryotrocha gen.n. and Anchidorvillea gen.n. An emended generic diagnosis of Ophryotrocha is provided to accommodate some of the new species, but also to include a group of atypical species described earlier by several authors who had modified the generic concept of Ophryotrocha without providing a formal emendation. The genus Ophryotrocha is revised to contain 31 species helonging to two species groups. A comparison of a suite of morphologic characters, however. indicates that these species addressed in this paper are discussed in the context of the entire family Dorvilleidae.

Plan-view photos, benthic grabs, and sediment-profile images: using complementary techniques to assess response to seafloor disturbance.

A monitoring survey was conducted in July 2005 at the Rhode Island Sound Disposal Site (RISDS) as part of the Disposal Area Monitoring System (DAMOS) program. The survey included the collection of sediment-profile and plan-view images, and benthic biology grabs. Each of these techniques provides a different, yet complementary perspective on benthic community conditions. These complementary techniques aided in the assessment of the benthic recovery process within RISDS following the placement of dredged material from the Providence River and Harbor Maintenance Dredging Project (PRHMDP). Based on observed patterns of physical, chemical, and biological responses of seafloor environments to dredged material disposal activity it was expected that the benthic community within RISDS would be in an intermediate phase of recolonization (Stage II). Results of the 2005 RISDS survey indicated that in the six months since disposal activities at RISDS had concluded, the biological community at RISDS was recovering relatively rapidly and Stages II and III infauna were present throughout the region.

New species of Chaetozone and Tharyx (Polychaeta: Cirratulidae) from the Alaskan and Canadian Arctic and the Northeastern Pacific, including a description of the lectotype of Chaetozone setosa Malmgren from Spitsbergen in the Norwegian Arctic.

Eight new species of cirratulid polychaetes of the genus Chaetozone from the Alaskan (Beaufort Sea) and Canadian Arctic (Baffin Island, Baffin Bay, Labrador, Hudson Strait, and Hudson Bay) and the Northeastern Pacific are reported together with two new species of Tharyx from the Alaskan Beaufort Sea and the Strait of Juan de Fuca. The new species of Chaetozone and Tharyx are compared with related species; distinct species groups within these genera are discussed. A redescription of C. setosa Malmgren, 1867, the type species of the genus from Spitsbergen, based on a lectotype and associated paralectotypes designated by the late Dr. Mary E. Petersen is presented. A review of characters important in the taxonomy of the genera Chaetozone and Tharyx is presented. A key to species of Chaetozone from the Northeastern Pacific and North American Arctic is provided.

A new species of Malacoceros (Polychaeta: Spionidae) from Kick'em Jenny, a hydrothermally active submarine volcano in the Lesser Antilles Arc

A new spionid polychaete, Malacoceros jennicus, is described from the crater of a hydrothermally active submarine volcano near Grenada in the Caribbean, Lesser Antilles Arc region. The new species is characterized by having prominent lateral frontal horns on the prostomium, paired eye spots, neurosetae that include simple capillaries, inferior sabre setae, numerous bidentate hooded hooks, and a pygidium bearing four digitiform anal cirri surrounding the anus. Worms were collected in regions of diffuse venting with a suction sampler deployed on an ROV. Specimens representing a range of sizes including sexually mature and reproductive individuals containing eggs and sperm were found. Stable isotope analysis of 13 C and 15 N indicate mixed feeding on photosynthetic and hydrothermal vent source material.

The Orbiniidae (Annelida: Polychaeta) of Pacific Costa Rica

Seven species of Orbiniidae are described from the Pacific coast of Costa Rica including two new species. Leodamas hamatus n. sp., a commonly occurring species on the coast of Pacific Costa Rica, is described from 11‒18 m in the Gulf of Nicoya and Bahia Culebra. This species is unusual in that the neuropodial uncini differ morphologically from anterior to posterior in the thorax. Scoloplos cryptospinigerus n. sp. is described from 18-22 m in the Gulf of Nicoya and has only a few short, toothed spines amidst numerous capillary setae in most of the thoracic neuropodia. This arrangement of thoracic neurosetae is unusual and has been seen only in one other described species of Scoloplos from Australia.

Redescription of Tharyx killariensis (Southern) from Ireland and description of two new species of Tharyx from the Kattegat, Sweden (Polychaeta, Cirratulidae)

Two new species of the cirratulid genus Tharyx are reported from shallow waters in the Kattegat inshore Sweden. In addition, the lectotype of Tharyx killariensis (Southern, 1914) is redescribed resulting in a revised concept of the noto- and neuropodial acicular spines of posterior parapodia for that species. These spines were originally reported as bidentate crotchets with sharply pointed teeth; in reality the spines have blunt, knob-shaped tips, typical of several other species of Tharyx. Both of the new species are atypical for the genus Tharyx. T. maryae n. sp. has an expanded posterior end more typical of the genus Aphelochaeta, but otherwise shares characters of Tharyx. T. robustus n. sp. has a body shape that is consistently broad and dorsoventrally flattened throughout, rather than elongate and narrow as in other species of the genus. Both of the new species, however, have short, blunt-tipped spines in far posterior parapodia. With the addition of the two new species, the genus Tharyx now includes 11 species that are compared and contrasted. Morphology that defines and characterizes species of Tharyx is reviewed.

A new species of Orbiniella (Polychaeta: Orbiniidae) from deep basins of Antarctica

During the 2002 Antarctic Deep-sea Biodiversity (ANDEEP) programme to the Drake Passage, Weddell Sea Basin and South Sandwich Slope and trench, a new deep-water species of orbiniid polychacte was collected: Orbiniella andeepia sp. nov. Orbiniella andeepia appears to be most closely related to O. marionensis but differs in capillary setal structure, the type and number of acicular spines found in each podial lobe. Orbiniella andeepia is only the third deep-water species of Orbiniella to be discovered. It exhibits both a wide depth- and geographic-range within the Antarctic slope and abyssal sediments.