Marine Flora and Fauna of the Northeastern United States Echinodermata: Crinoidea

The crinoid fauna of the continental margin (0-1500 m) of northeastern North America (Georgia to Canada) includes 14 species in 13 genera and 5 families. We introduce the external morphology and natural history of crinoids and include a glossary of terms, an illustrated key to local taxa, annotated systematic list, and an index. The fauna includes 2 species found no further south than New England and 8 that occur no further north than the Carolinas and Blake Plateau. Comactinia meridionalis (Agassiz) is the only species commonly found in shallow water «50 m). No taxa are endemic to the area. (PDF file contains 34 pages.

Neotanais persephone, a New Species of Hadal Tanaidacean (Crustacea: Peracarida)

Neotanais persephone, a new species of tanaidacean and the first reported from the Puerto Rico Trench, is described and figured. The material represents the greatest depth record for the order from the Atlantic Ocean and for the genus worldwide. The species is placed within the americanus group of species and is most similar to N. hadalis Wolff. Rudimentary oostegites are present on several copulatory males

A Revision of the Comatulid Genus Comactinia A. H. Clark (Crinoidea: Echinodermata)

The formerly monotypic genus Comactinia is found to comprise two valid species. One of these is further divided into two subspecies. The variability of the genus is examined and illustrated. A discussion of ecology, affinities, and zoogeography is included

North Fork of the New River Benthic Macroinvertebrate Recruitment Study: Final Report

Over the last several years, the Broward County Department of Natural Resource Protection has identified a series of major environmental problems in the North Fork of the New River, including illegal wastewater sludge discharge and heavy metal contamination of sediments (DNRP 1993 1994). A qualitative survey suggests that benthic macroinvertebrates have been negatively affected (DNRP 1997). Restoration projects have included removal in the summer of 1997 of a remnant sludge blanket from an area of the channel east of Interstate 95 and north of Broward Boulevard. However, the effectiveness of such dredging in terms of habitat restoration has not previously been examined. This report documents the results of four sampling events carried out in order to investigate the response to such dredging of benthic macroinvertebrate assemblages in the North Fork of the New River

Postmarsupial Development and Growth of Pagurapseudes largoensis McSweeny (Crustacea, Tanaidacea)

Postmarsupial development of the gastropod shell-inhabiting tanaidacean Pagurapseudes largoensis McSweeny is described and compared with that of Heterotanais oerstedii (Krøyer) and Neotanais micromopher Gardiner. This is the first such study of an apseudomorphan based on experimentally reared animals. P. largoensis is gonochoristic; two manca instars are typical of all tanaidaceans so far investigated. In females, the mancas are followed by two or possibly three juvenile instars (=neutra), one or two preparatory instars characterized by rudimentary oostegites, and a copulatory stage with complete marsupium. Laboratory maintained animals pass through up to three copulatory stages, each separated by a preparatory stage of one or two instars. A preparatory instar, characterized by very small rudimentary oostegites often restricted to thoracopods VI, sometimes occurs between the juvenile and normal preparatory stages. The small number of such field-collected specimens suggests that it is an abnormality. Males develop either directly from the manca 2 instar or from the first juvenile instar. Pleopods and heterochelae either accompany initial appearance of genital cones or appear after one or two additional molts. Males retain a full set of mouthparts, feed, and molt throughout their lives. Variability in the pattern of instar succession may be construed as a primitive trait and supports the position of the Apseudomorpha as least derived of the three tanaidacean suborders. Males alone are heterochelous; the right chela is always major and its growth is allometric with respect to carapace length. Intermolt period increases with age, from a 2-week mean for mancas 1 to about 4 weeks for preparatory and copulatory females and 7 weeks for large males, although minimum intermolt periods are similar for all stages (11-29 days). Longevity is estimated at up to 15 months for males and 9 months for females. The sex ratio for field-collected specimens is about 1:1. Females bear 4-17 offspring per marsupium

Porphyrocrinus daniellalevyae n. sp. (Echinodermata: Crinoidea), a sea lily from the tropical western Atlantic with a unique crown pattern

Porphyrocrinus daniellalevyae, new species, is described from irregular, hard-substrate, deep island slope habitats in the tropical western Atlantic Ocean (northwestern Bahamas and, probably, Honduras). It represents the first record of the genus from the western Atlantic, and is the first crinoid, living or fossil, known to gradually increase its number of rays with increasing size and, ostensibly, growth. The four known specimens have 8, 12, 14 and 15 radial ossicles, which give rise to undivided arms. The method of augmentation is unknown, although the possibility of autotomy of one and regrowth of two in its place is discussed. Augmentation of radial number may also account for the absence of an aboral nerve ring associated with the radial ring, unlike the arrangement in almost all living crinoids in which the nervous system has been examined. Ligamentary articulations (trifascial synarthries) exhibit fulcral ridge- and groove architecture between arm ossicle pairs that remains to be described for other members of the genus. The species also exhibits a filamentous arm tip lacking pinnules that has only been described for one other species of Porphyrocrinus

Notes on Recent Changes in Tanaidacean Terminology

no abstract availabl

Three New Species of Comasteridae Echinodermata, Crinoidea from the Tropical Western Pacific

Three new species of unstalked crinoids (Echinodermata, Crinoidea) belonging to the comasterid genera Comactinia A. H. Clark, 1909, Capillaster A. H. Clark, 1909, and Cenolia A. H. Clark, 1916 from depths of 73-310 m, are described. Comactinia titan n. sp., from the Philippines and New Caledonia, which bears thicker arms than any other comasterid, is the first representative of its genus recorded outside the tropical western Atlantic. Capillaster squarrosus n. sp., from Vanuatu, resembles C. multiradiatus (Linnaeus, 1758) but has uniquely modified arms. Cenolia amezianeae n. sp., from southern New Caledonia and Vanuatu, resembles its congeners but bears combs on pinnules as far as P19 (rather than just to P4 as in other Cenolia), which requires an emendation of the generic diagnosis

A Revision of the Genus Atelecrinus PH Carpenter (Echinodermata: Crinoidea)

The unusual bathyal comatulid crinoid genus Atelecrinus is widespread in the Atlantic and tropical Pacific Oceans and currently includes three recognized species. A re-assessment based on examination of new and existing specimens requires establishment of two new genera and five new species, and returns three junior synonyms to species-level status. Paratelecrinus is erected to accommodate Atelecrinus wyvilli PH Carpenter, A. conifer AH Clark, A. cubensis PH Carpenter, P. orthotriremis, new species, P. amenouzume new species, P. laticonulus new species, and P. telo new species. Adelatelecrinus is erected to accommodate Atelecrinus sulcatus AH Clark and Adelatelecrinus vallatus new species. Atelecrinus retains A. balanoides PH Carpenter and A. helgae AH Clark, which restricts the genus to the Atlantic. In both Paratelecrinus and Adelatelecrinus, the basals articulate with the centrodorsal via ligament bundles anchored in deep ring-like interradial pits that project into the centrodorsal cavity, whereas in Atelecrinus the centrodorsal rim has shallow interradial concavities and attaches to the basals via a tight junction with no obvious ligament bundles. The spoon-shaped absoral fossa in the basals of Paratelecrinus appears to be unique among articulate crinoids and differs from the smooth fossa found in both Atelecrinus and Adelatelecrinus. New material extends the range of the family to the Indian Ocean. A few species are now known from enough specimens to identify some ontogenetic and distributional variations. Proximal ray morphology varies substantially with size in P. cubensis and P. orthotriremis. A balanoides generally occurs in deeper water in the Lesser Antilles than in the Bahamas and Strait of Florida, while P. orthotriremis occurs in shallower water in the Lesser Antilles and deeper in the Bahamas

Compositional and Taphonomic Variations in Modern Crinoid-Rich Sediments from the Deep-Water Margin of a Carbonate Bank

Multivariate analyses of the coarse-grained fraction (\u3e2 mm) of sediments accumulating in deep water (419-434 m) along the western margin of the Little Bahama Bank reveal identifiable, small-scale compositional and taphonomic variations among local subhabitats (ridge crest, slope, foreslope, base of slope, pavements and scour pit) separated by meters to tens of meters. Bulk composition varies between planktic-(crest and slope) and lithic-dominated (pavements, scour pit) sediments. Local macrobenthic skeletal components also vary significantly among subhabitats, but are commonly dominated by echinoid and crinoid material; crinoid columnals contribute 9-52% of the coarse skeletal component of 17 sediment samples considered. Distributional and taphonomic analyses (abrasion, encrustation, breakage) indicate that columnals produced in dense ridge-crest assemblages of Chladocrinus decorus are transported down and accumulate along an adjacent slope. Sediments from hardgrounds supporting scattered living assemblages show columnals with the highest levels of abrasion, implying prolonged local reworking. Elevated contributions of Endoxocrinus parrae columnals to the few subhabitats where this species dominates the living assemblage suggest limited lateral transport in the absence of steep gradients. High levels of biological encrustation in areas of thin sediment cover suggest control by length of exposure of grains at the sediment-water interface. Lack of any correlation between frequency of broken columnals in samples and any observed sedimentary or environmental parameters suggests the action of predators or scavengers in this deep-water setting. Small-scale variations in sediment composition, benthic skeletal assemblages, and taphonomic characteristics are not unique to shallow-water settings, but can also be identified in deep-water carbonate bank-margin sediments. Such changes are largely a response to differences in benthic flow regime associated with small-scale topographic irregularities and may provide an important diagnostic tool for the interpretation of fossil assemblages