Eulima, Risso, 1826

Souza, Leonardo Santos De, Pimenta, Alexandre Dias & Barros, José Carlos Nascimento De, 2021, Revision of the deep-sea Eulimidae (Gastropoda, Caenogastropoda) from off Northeast Brazil, Zootaxa 4927 (4), pp. 451-504 : 466-468

publication ID

https://doi.org/10.11646/zootaxa.4927.4.1

publication LSID

lsid:zoobank.org:pub:AED51D9E-1751-4010-A8E1-B72AE428821A

DOI

https://doi.org/10.5281/zenodo.4542955

persistent identifier

https://treatment.plazi.org/id/03E687A2-FFB1-FFCF-FF5F-873EFDC2450D

treatment provided by

Plazi

scientific name

Eulima
status

 

Eulima sp. 1

( Figure 8 View FIGURE 8 A–I)

Material examined. Brazil: Rio Grande do Norte: REVIZEE Nordeste (04°51′00″S 35°06′00″W, 375 m), coll. RV Natureza, 24/xi/2001: MNRJ 29631 View Materials † [1 dd], MNRJ 35215 View Materials † [1 dd] GoogleMaps .

Description. Shell conical, apex rounded, reaching about 6.4 mm long, 1.6 mm wide. Larval shell with about 2.5 whorls, 290 µm wide, 370 µm in height; smooth, transition to teleoconch marked by a subtle incremental scar. Teleoconch with about 7.5 whorls, almost flat; suture shallow, slightly impressed, sloping; surface glossy and smooth; incremental scars weak, appearing at irregular intervals. Last whorl about 50% of the shell length; base elongated, slightly rounded outline, connected close to the most anterior region of the aperture. Aperture high, narrow, pear shaped, acute posteriorly and rounded anteriorly; outer lip thin, slightly sinuous, opisthocline, slightly projecting near the suture and slightly retracting in the distal region; inner lip sinuous, sloping and well demarcated. Not umbilicate. Shell vitreous or whitish, with a brownish spiral band at the suture of the larval shell.

Measurements. MNRJ 29631, 10 whorls, SL= 6.4 mm; BWL= 3.2 mm; AL= 2.3 mm; SW= 1.6 mm; AW= 1.0 mm.

Remarks. The shell surface of the two specimens examined is corroded ( Figure 8E View FIGURE 8 ) and at first, it seems that it presents a sculpture of axial lines, like some species in the genera Melanella Bowdich, 1822 and Niso Risso, 1826 . However, this is an artifact as examined in SEM and there are only incremental scars ( Figure 8E View FIGURE 8 ). The general shape and the aperture are more similar to Eulima s.s.

Other Eulima species that resemble Eulima sp. 1 are E. psila ( Figure 6 View FIGURE 6 A–M) and E. grimaldii ( Figure 6P, Q View FIGURE 6 ), both with a brownish spiral band at the protoconch. However, Eulima sp. 1 differs from E. psila by features of the protoconch, which has a smaller number of whorls (2.5 vs. 3.5 in E. psila ) and is shorter (370 µm vs. 420 µm), and by the outline of the outer lip, which is slightly protruding in E. sp. 1 ( Figure 8G View FIGURE 8 ) and straight in E. psila ( Figure 6I View FIGURE 6 ). Eulima sp. 1 also differs from E. grimaldii by features of the protoconch, which has less convex whorls in E. sp. 1 (see Figure 8H View FIGURE 8 and Bouchet & Warén 1986: figure 93) and a smaller number of whorls (2.5 vs. 3.3 in E. grimaldii ). Furthermore, the body whorl comprises 50% of the shell length in E. sp. 1 and 40% of the shell length in E. grimaldii , and the aperture is relatively wider and higher in E. sp. 1 comparing shells with a similar number of whorls (AL= 2.3 mm, AW= 1.0 mm vs. AL= 1.6 mm, AW= 0.7 mm, holotype of E. grimaldii ).

Eulima sp. 1 can also be distinguished from Eulima incolor ( Figure 5F, G View FIGURE 5 ) by the brownish spiral band on the protoconch, which is not present in E. incolor , and by the presence of several incremental scars on the teleoconch, while Bouchet & Warén (1986) described that E. incolor does not present any incremental scar on the teleoconch.

Despite the differences mentioned above, we refrain to name Eulima sp. 1 as a new species because of the almost inconspicuous features of the species. Most species of Eulima s.s. are very similar to each other, especially those that do not have a colored teleoconch and we prefer to leave this species undescribed until more samples become available.

Geographical distribution. Brazil: Rio Grande do Norte.

Bathymetric distribution. 375 m.

Kingdom

Animalia

Phylum

Mollusca

Class

Gastropoda

Order

Caenogastropoda

Family

Eulimidae

Genus

Eulima