Records and Descriptions of Epitoniidae ( Orthogastropoda : Epitonioidea ) from the Deep Sea off Northeastern Brazil and a Checklist of Epitonium and Opalia from the Atlantic Coast of South America

1 Departamento de Sistemática e Ecologia, Universidade Federal da Paraı́ba (UFPB), 58059-900 João Pessoa, PB, Brazil 2 Laboratório de Malacologia, Departamento de Pesca e Aquicultura, Universidade Federal Rural de Pernambuco (UFRPE), Avenida Dom Manuel de Medeiros S/N, Dois Irmãos, 52171-030 Recife, PE, Brazil 3 Departamento de Zoologia, Instituto de Biologia, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro (UFRJ), Ilha do Fundão, 21941-570 Rio de Janeiro, RJ, Brazil

Brazilian programs of environmental characterization have been very important in the sampling of benthic communities from the continental shelf and deep waters.For example, Miyaji [30] identified five genera and 16 species of Epitoniidae collected in southeastern and southern Brazil
Remarks.This species is similar to Epitonium krebsii (Mörch, 1875) in the globose-turbinate shell and blade-like ribs widely spaced and slightly abaperturally recurved at the shoulder but differs in that it has numerous fine spiral threads and does not have the wide umbilicus characteristic of E. krebsii.Clench and Turner [32], Abbott [37], and Rios [21] did not recognize any spiral sculpture on the teleoconch of E. krebsii.
The only specimen collected matches Epitonium celesti in the conical protoconch with about 4 whorls as well as in the shell shape and in axial and spiral sculpture (see Bouchet and Warén [16]).The prominent axial ribs strongly recurved abaperturally at the shoulder forming a spine in Epitonium celesti that seems to be somewhat different from the specimens illustrated herein.However, the only shell collected here is somewhat worn.Characterization.Shell conical-turbinate (Figure 3(a)).Protoconch conical, about 3.5 whorls, sculptured with subsutural spiral threads and opisthocline incremental lines (Figure 3(b)).Teleoconch about 3.5 whorls attached by prosocline blade-like ribs, slightly expanded, angulated, and with weak spine at shoulder (Figures 3(a) and 3(c)).Microscopic sculpture of numerous spiral threads (Figure 3(c)).First, second, and third teleoconch whorl sculptured with about 14, 18, and 22 axial ribs, respectively (Figure 3(a)).Suture deep and very constricted.Base conical, moderately elongated.Aperture oval.Outer and inner lip thin.Umbilicus minute, partially hidden by parietal lip and ribs (Figure 3(a)).
Geographic Distribution.Eastern Atlantic-Bay of Biscay to Cape Verde Islands [46]; western Atlantic-continental slope of Rio Grande do Norte (northeast Brazil: present study).
Alora sp. is an undescribed species from the Atlantic Ocean.Dr. R. S. Absalão (pers.comm., April 2011) identified this species for the Campos Basin (Brazil: Rio de Janeiro) based on dozens of specimens.A formal specific epithet is being provided by this researcher.Alora sp. and A. tenerrima are similar in the convexity of the teleoconch whorls (except for the last whorl), in the dominating spiral sculpture, in the shape of the aperture, parietal region, and straight inner lip, in the deep suture and in the enlarged umbilicus (half-moon shape).Alora sp.differs from A. tenerrima by the presence ofa peripheral carina, more numerous and weaker spiral threads, more closely spaced axial incremental lines, and a subtrigonal, not regularly convex last whorl.Alora tenerrima has about 5 spiral threads above the peripheral cord and 7 to 9 stronger threads below the cord; axial incremental lines are well spaced, and the last whorl is globose and regularly convex [16].
Remarks.This species is described in some studies as imperforate [6,22].In some specimens, however, there is a small chink-like umbilicus [49].Although not usually in the description of this species, varices are seen in the images [6,22].Remarks.Opalia revizee new species is similar to and may be confused with O. eolis and O. fortunata Bouchet and Warén, 1986, due to the presence of a varix.Opalia revizee and O. eolis are similar in the presence of a thickened outer lip, numerous microscopic pits, and a varix on the teleoconch.Opalia revizee is distinguished from O. eolis by the absence of a crenulated suture, spiral sculpture, axial threads, and ribs.Opalia eolis displays a crenulated suture, heavy axial ribs, and strong spiral cords [6,37,49].
Opalia fortunata (northeastern Atlantic) is the species most closely related to O. revizee.Both have a similar outline of the shell, 3 whorls on the protoconch, about 5 whorls on the teleoconch, whorls regularly convex and sculptured with microscopic pits, a prosocline varix, a regularly convex base, a thickened and complete peristome, and the absence of a basal ridge or basal disk.Opalia revizee differs from O. fortunata by exhibiting an ovate aperture, surface covered with intritacalx densely sculptured with spiral rows of microscopic pits and no axial ribs or crenulated suture.Opalia fortunata has a rounded aperture, whorls covered by a smooth, finely pitted intritacalx, weak axial ribs, and suture weakly crenulated [16].Description.Shell whitish, small, strong, thick, conical (Figure 10(a)).Protoconch with about 2 moderately convex whorls, sculptured with microscopic pits (Figure 10(c)).Spire moderately high (Figure 10(a)).Suture moderately deep (Figures 10(a)-10(c)).Teleoconch with about 6 constricted whorls; whorls strongly convex, irregular in outline (Figure 10(a)); surface covered by intritacalx densely sculptured with microscopic pits in square pattern (Figure 10(b)).Axial sculpture with strong, thick, high, rounded, prosocline, widely spaced ribs that do not form crenulations in subsutural region (Figures 10(a) and 10(b)).Last whorl sculptured with 10 to 14 axial ribs, faint on basal ridge, weakly invading basal disc (Figure 10(d)).Base delimited posteriorly by prominent ridge keel (Figure 10(d)).Basal disc strongly flattened, large, sculptured with microscopic pits, weak ribs; prominent spiral rib at periphery of inner lip, with nodules in intersection of axial ornamentation (Figure 10(d)).Aperture rounded (Figures 10(a  Remarks.The taxon Gregorioiscala Cossmann, 1912, was erected to include deep-water epitoniid species with noncrenulated sutures, a relatively wide basal disk and a strongly defined basal ridge, thickened outer lip, thick pitted intritacalx, and strong axial ribs, some of which may form varices [16,58].About 14 Gregorioiscala species are currently known in seas worldwide [16,55,58].Gregorioiscala pachya (Locard, 1897) is the only deep sea congener reported for the western Atlantic (Gulf of Mexico) [55].
Gregorioiscala pimentai resembles G. pachya in presenting a teleoconch with constricted whorls; whorls irregular in outline; strong, thick, prosocline, widely spaced axial ribs, axial ribs of subsequent whorls not aligned in a row, suture International Journal of Zoology moderately deep, and peristome thickened.Gregorioiscala pimentai is distinguished from G. pachya by the presence of a conical, less solid shell, teleoconch with 6 whorls, columellar axis not curved, teleoconch whorls not developing a shoulder, lacking varices, basal disc sculptured with weak axial ribs and a spiral rib present at the periphery of inner lip, forming nodules in the intersections with axial ribs.Gregorioiscala pachya is recognized by the turriculate, very solid, heavy shell, teleoconch with about 12 whorls, curved columellar axis, shouldered teleoconch whorls, some axial ribs forming varices and basal disc not sculptured with ribs [16].
The genera Amaea and Gregorioiscala are among the most poorly represented epitoniids on both Atlantic coasts and species richness values therefore have little comparative meaning between regions.The two Amaea species from the western Atlantic are spread over a broad geographic area [6,9,22,37,39,55,57], but only A. retifera has been recognized as significantly expanding the area of occurrence of the group to the Atlantic coast of South America and apparently beyond the continental shelf [22].Other species have been found in the eastern Atlantic off West Africa (A. africana Bouchet and Tillier, 1978; A. guineensis Bouchet and Tillier, 1978) [9,42,59].
The genus Epitonium has the highest number of described epitoniids [7-9, 11, 14, 22, 23, 32, 37, 39], with about forty species on both sides of the Atlantic [42,43].Currently, the Epitonium fauna of the western Atlantic may be divided into six categories on the basis of their distribution: (A) amphi-Atlantic species (4.79%); (B) species widely distributed from the United States to the Caribbean Sea and the Atlantic coast of South America (38.09%); (C) species distributed from the United States to the Caribbean Sea (16.66%); (D) species known only for the coast of the United States (16.66%); (E) species known only for the Caribbean Sea (11.90%); (F) species restricted to the Atlantic coast of South America (11.90%).
The data reviewed here reveal that Epitonium fauna with the greatest similarity occur between the Caribbean Sea and the Brazilian coast, as nearly half the species have records in both regions [7,22,32,37,41,43,49].In the western Atlantic, about 20 species (47.61%) are found at depths of less than 200 m, while the other half has also been collected from deep waters [43].In South America, the vertical range of Epitonium as a whole extends from the sublittoral zone (15 species; 42.8%) to the bathyal zone (20 species; 57.2%) (Table 1).
The only studies documenting Epitonium species in subregions of the Atlantic coast of South America were carried out by Diaz and Puyana [39] for Colombia (at least 16 species) and Rios [19][20][21][22] for Brazil.Not surprisingly, the Brazilian coast has the greatest richness of Epitonium in South America, with at least 25 species (Table 1) [22,23,31,32,37,41,44].However, this total is far from being considered satisfactory due to the vast areas with scarce or no information on Epitoniidae.

Table 2 :
Checklist of species of the genus Opalia known for the Atlantic coast of South America with geographic and bathymetric distribution.