Smithsonian Digital Repository: the Deep-Sea Buccinoidea (Gastropoda: Neogastropoda) of the Scotia Sea and Adjacent Abyssal Plains and Trenches

Smithsonian Digital Repository: the Deep-Sea Buccinoidea (Gastropoda: Neogastropoda) of the Scotia Sea and Adjacent Abyssal Plains and Trenches

Smithsonian Digital Repository: The Deep-Sea Buccinoidea (Gastropoda: Neogastropoda) of the Scotia Sea and Adjacent Abyssal Plains and Trenches Search Repository Smithsonian Digital Repository > National Museum of Natural History > Department of Invertebrate Zoology > Advanced Search Home Please use this identifier to cite or link to this item: http://hdl.handle. net/10088/8306 Browse Title: The Deep-Sea Buccinoidea (Gastropoda: Neogastropoda) of the Communities Scotia Sea and Adjacent Abyssal Plains and Trenches & Collections Authors: Harasewych, M. G. Issue Date Kantor, Y. I. Author Issue Date: 2004 Title Citation: The Nautilus, 118(1): 1-42 URI: http://hdl.handle.net/10088/8306 Appears in Collections: Department of Invertebrate Zoology Help About DSpace Files in This Item: File Description Size Format 19.51 View/ iz_Harasewych_Kantor_2004.pdf Adobe PDF MB Open Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated. DSpace Software Copyright © 2002-2009 The DSpace Foundation - Feedback http://si-pddr.si.edu/dspace/handle/10088/830609.02.2010 15:29:43 TIIF. NAUTILUS 118(l):l-42, 2004 Pagel The deep-sea Buccinoidea (Gastropoda: Neogastropoda) of the Scotia Sea and adjacent abyssal plains and trenches M. G. Harasewych Yuri I. Kan tor Department o( Systematic Biolugv Scvert/ov Institute National Museum of Natural History Russian Academy oF Sciences Smithsonian Institution Leninski Prospect 33, Washington, DC 20013-7012 USA Moscow 11T071 RUSSIA ABSTRACT [Valanginian] (Tracey et al., 1993), these predatory snails have* radiated to occupy most benthic marine habitats Four new genera and species of buccinoidean gastropods, S/H- W;»cr/nmn s/p/f/imiff/r new genus, new species: Dn^M/wof/on- ranging from the tropics to the poles and from the in- /ff.s /o/z/f/Nf/c new genus, new species; Afff^zn/wcr/HMMi cof/i- tertidal zone to hadal depths (Clarke, 1962). Several cdnf/f new genus, new spi-cies; and (x/ifionro n/rWw new members of the families Nassariidae and Buccinidae genus, new species, are described from the Scotia tectonic have even invaded fresh water (Kantor and Kilbum, plate and adjacent alwssal plains. Only fW/w/f/oMH? (V;fM^»& 2001; Brandt and Temcharoen, 1971). "Uncle, 1912, TTtMn/no /W/m r//;f/w/n)/f/ Clarke, 1961 and 71 Bueeinoideans are readily distinguished by their usu- m/jf/vwrnmi Lus, 1993, had prcviouslv been reported from aliys- ally weakly sculptured, conical to fusiform shells, their sal depths off Antarctica. The latter two species were proposed distiuctivc rachiglossan radula with multicuspid lateral in the genus Th)Himr7. sulmciaicutly shown to belong to the teeth, long to very long proboscis, as well as by the ab- family Muricidar. Therefore, a new genus. /^isf/mmf#im is pro- sence of a rectal gland and accessory salivary glands. posed for those abyssal and hadal buccinoidean species. Anal- yses of the taxonomic placement, geographical and l)athymctric Their relationships to other Neogastropoda, however, distribution, and diversity o( the 29 buccinoidean genera prcs- have been variously interpreted, ranging from basal to ently known from Antarctica and the Magellanic Province have derived (e.g., Ponder, 1974; Ponder and Wardn, 1988; shown that the abyssal (>2200 m) buccinoidean fauna of the Ponder and Lindbcrg, 1996; Kantor, 1996; Harasewych region shares no genera with the sublittoral or bathyal faunas. et al., 1997). While a number of authors have attributed None of the six aliyssal genera conform readily to the sublam- different taxonomic ranks to Buccinoidea and its com- ilies rcpnvicutcd b\ the sublittoral or lialhval faunas. (Credible ponent higher taxa (e.g., Powell, 1929; Thiele, 1929; sister taxa and likely origins (or some abyssal genera occur on Wcnz, 1938; Ponder, 1974; Ponder and Waren, 1988), the adjacent continental slope. For others, closest relatives may there is little disagreement as to the monophyly or com- Ix- Ibund on ahysail plains beyond the Antarctic convergence. Generic diversity decreases with increasing depth for both the position of the group. We had earlier briefly reviewed bathyal and abyssal buccinoidean (annas, while bathvmetrie the history of the higher classification of bueeinoideans range tends to increase. For abyssal bueeinoideans, maximum (Harasewych and Kantor, 1999), which is based primarily generic diversity occurs l)etween 2600 and 32(X) meters. The on differences in shell, opcrcular and radular morphol- proportion of monotypic genera in the Antarctic and Magel- ogies applied to regional faunas (e.g., Powell, 1929, lanic Provinces is extraordinarily high (48.3%), and may be an 1951, Southern Oceans; Habe and Sato, 1973, Northern artefact of low sampling density exacerbated by difficulties in Pacific; Bouchct and Warf n, 1985, Northeastern Atlan- differentiating closely related species. Neither gigantism nor tic). We continue to retain provisionally the use of Buc- dwarfism is evident in the abyssal buccinoidean fauna. Rather, ciimlidae and its subdivisions, as defined by Powell the range in sixes narrows with increasing depth. Genera in- habitiug the base of the continental slope are smaller than (1951), without necessarily endorsing their taxonomic those of either the upper slope or continental rise. In the abys- rank, for the antiboreal members of the Buccinoidea, sal zone, maximum shell size is reached near the boundary of pending the availability of sufficient anatomical and/or the continental rise and ahys&il plain, and subsequently de- molecular data for a meaningful phylogenetic revision of creases with increasing depth. the higher taxa of Buccinoidea on a global basis. The subfamilial assignments of presently known buccino- idean genera that occur south of the Antarctic Conver- INTRODUCTION gence, as well as those from the Magellanic Province are reviewed (Appendix 1) and, in some cases, revised. The Buccinoidea are the most geographically wide- Our continuing studies of the Buccinoidea represent- spread and ecologically diverse clade within the Neo- ed in the collections assembled by the United States gastropoda. First appearing during the Early Cretaceous Antarctic Program (USAP) have revealed a number of I'age 2 THE NAUTILUS, Vol. 118, No. 1 previously undescribed taxa from the abyssal plains and teriorly. Posterior oesophagus forms crop before enter- trenches on and adjacent to the Scotia Plate. These taxa ing simple, U-shaped stomach, which has a well-defined are described herein, and their affinities to other Ant- gastric shield. arctic and abyssal huccinoideans are discussed. Etymology: This genus is named after Spike, a Cor- nish Rex cat that belongs to the senior authors daughter MATERIALS AND METHODS Steplianie. This report is based primarily on huccinoideans sorted from the abyssal stations sampled by the United States Sp*&e6uccfnww &ky;/wnMg new species Antarctic Program (USAP) vessels R/V IsLAS OncADAS (Figures 1-23, Table 1) and R/V ELTANix and housed in die collections of the Description: Shell (Figures 1-3, 5-7, 9, 10) small (to National Museum of Natural History (USNM). Addi- 19.9 mm), very thin, translucent, ovate, with rounded tional material, sampled by die German vessel R/V Po- anterior, eroded spire. Protoconch (Figure 11), known LARSTKHN and in the collection of die Zoological State from a single juvenile (Paratype 12), increasing in di- (Collection, Munich (ZSM) were made available through ameter from 0.4 mm to 3.5 mm, in 2% smooth, evenly the kindness ol Enrico Schwabc and Michael Schrodl. rounded, pitted whorls. Transition to teleoconch distin- In the material examined sections, "specimen" de- guished 1)y slight cliange in color, from cream to white, notes that a preserved animal is present, while "shell" and by abrupt transition from coarse, irregular axial refers to a record based only on an empty shell. Ana- growth striae, to finer, regular growth lines. Protoconch tomical descriptions are based on gross dissections of and upper whorls eroded on all odier specimens. Ex- preserved specimens. Radulae were removed by gross trapolation from growdi series suggests that teleoconch dissection, cleaned using diluted bleach (NaOCl), coated may reach 5-6 whorls, of which all but last 2-2% whorls with carbon and gold, and examined using a LEO 440 eroded. Whorls evenly rounded, with indistinct shoulder, Scanning Electron Microscope. Photographs were taken abutting suture. Axial sculpture limited to very fine, using a Nikon Dl Digital Camera with a AF Micro Nik- straight, strongly prosocline growth lines. Spiral sculp- kor 60 mm lens. Images were processed using Adobe ture of fine, sharp, uniform, evenly spaced cords (21-29 Photoshop 6.0. on final whorl, 11-14 on penultimate whorl). Aperture The following abbreviations are used in die text: AL— large (AL/SL = 0.60-0.67 when using length of eroded aperture length, D—diameter, FWL—final whorl shell; AL/SL = 0.50-0.55, as estimated by linear projec- length, I^-length, IVW—length/width, SCL—Siphonal tions of apex), broadly oval, deflected from shell axis by canal length, SL—shell length, SW—shell width, W— 22-25*. Outer lip very thin, not reflected, evenly round- width. ed (rom suture to siphonal notch. Inner lip consists of a long, straight parietal region that meets the shorter, con- SYSTEMATICS cavely indented axial portion of columella, ending in (Class Gastropoda Cuvier, 1797 strong siphonal fold. Columella shorter than aperture, Order Neogastropoda Wenz, 1938 giving rise to a broad siphonal notch. Parietal callus uni- Superlamiry Buccinoidea Rafinesque,

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