Micratys wareni, Valdés, 2008

Valdés, Ángel, 2008, Deep-sea “ cephalaspidean ” heterobranchs (Gastropoda) from the tropical southwest Pacific, Mémoires du Muséum national d'Histoire naturelle 196, pp. 587-792 : 770-772

publication ID	978-2-85653-614-8
persistent identifier	https://treatment.plazi.org/id/03D087B2-FF53-BE97-FEE3-77D8F6CDFEA6
treatment provided by	Felipe
scientific name	Micratys wareni
status	sp. nov.

Treatment

Micratys wareni View in CoL n. sp.

Figs 93A-C, 94

TYPE MATERIAL. — Holotype MNHN 20435 and 5 paratypes MNHN 20436-20440, 2 paratypes LACM 3010 View Materials .

TYPE LOCALITY. — South of New Caledonia, 22°14’S, 167°29’E, 1300-1475 m [BIOCAL: stn CP 74] GoogleMaps .

MATERIAL EXAMINED. — Philippines. MUSORSTOM 2: stn 3010); stn CP 698, 20°34’S, 164°57’E, 491-533 m, 1 lv, destroyed DR 34, 13°28’N, 121°12’E, 155-167 m, 1 dd GoogleMaps . — MUSORSTOM to dissect the radula, paratype ( MNHN 20439 View Materials ; Fig. 93C) .

3: stn CP 100, 14°00’N, 120°18’E, 189-199 m, 1 dd; stn DR 102, Loyalty Ridge. BIOCAL: stn DW 80 , 20°32’S, 166°48’E, 900-980 14°01’N, 120°18’E, 192 m, 1 dd; stn CP 143, 11°29’N, 124°11’E, m, 1 dd, paratype (MNHN 20440) GoogleMaps . — BATHUS 3 : stn DW 793 , 205- 214 m, 9 dd. Mont J, 23°47’S, 169°49’E, 731-751 m, 1 dd GoogleMaps .

Indonesia. KARUBAR: stn CP 89, Tanimbar Islands, 08°39’S, New Hebrides Arc. VOLSMAR: stn DW 30, Hunter and Matthew 131°08’E, 1058-1084 m, 1 dd. Islands, 22° 17’S, 171°18’E, 450-550 m, 1 dd.

Coral Sea. MUSORSTOM 5: stn 321, 21°20’S, 158°02’E, 1000 m, Fiji. MUSORSTOM 10: stn CP 1325, Bligh Water , 17°16’S, 1 dd, paratype ( MNHN 20436 View Materials ). 177°50’E, 282-322 m, 2 dd GoogleMaps . — BORDAU 1 : stn CP 1402, 16°38’S, New Caledonia proper. BIOCAL: stn CP 23, 22°46’S, 166°20’E, 179°36’E, 260-279 m, 1 dd GoogleMaps .

2040 m, 1 lv, paratype ( MNHN 20437); stn CP 74, 22°14’S, Wallis Island. MUSORSTOM 7: stn DW 523, 13°12’S, 176°16’W, 167°29’E, 1300-1475 m, 1 dd, holotype ( MNHN 20435; Figs 93A, 455-515 m, 2 dd.

B). — BIOGEOCAL: stn KG 211, 22°42’S, 166°33’E, 975 m, 1 dd, Tonga. BORDAU 2 : stn DW 1569 , NW of Tongatapu, 21°02’S, paratype ( MNHN 20438 View Materials ) GoogleMaps .— BATHUS 1 : stn DE 697, Passe de Hien- 175°19’W, 433 m, 1 dd .

ghène, 20°34’S, 164°58’E, 570-650 m, 2 dd, paratypes ( LACM

DISTRIBUTION. — Collected in the Coral Sea, Fiji, Hunter and Matthew Islands, Indonesia, New Caledonia, Philippines, Tonga and Wallis Island (Fig. 94), in 167-2040 m, live in 533-2040 m.

DESCRIPTION. — Shell morphology. Length 5 mm, width 3.5 mm (largest specimen examined). Shell solid, oval, with convex sides (Fig. 93A). Only 1 whorl visible, forming the entire shell. Apex rounded, depressed, with a narrow umbilicus (Fig. 93B) and the aperture lip rising from the left side. Anterior end of the shell rounded. Umbilicus present, partially covered by the columella. Aperture long, wide anteriorly, narrowing at about 1/3 of its length. Columellar margin thickened. Sculpture of about 4 simple spiral grooves near the posterior end and about 6 grooves near the anterior end. These grooves are absent from the central part of the shell and are more densely arranged near the anterior and posterior ends. Colour uniformly white.

Anatomy. The radular formula is 14 x 4.1. 4 in one dried specimen examined ( BATHUS 1 CP 698). The rachidian tooth is elongate with 6-7 pointed denticles (Fig. 93C). The innermost lateral teeth are wide, hamate, with a broad lateral protuberance on the outer side, near the base. The long, curved cusp bears 7 sharp denticles on the inner side. The rest of the lateral teeth are also hamate but narrower and smooth, with no denticles, and considerably smaller.

REMARKS. — This species is placed in the genus Micratys because of the oval shape of the shell, with a slightly perforated apex and a well-developed umbilicus, and the sculpture of spiral striae, absent from the central part of the shell.

The other described species of the genus is Micratys ovum Habe, 1952 , from Japan, which has a smaller and proportionately shorter shell. Since the radula of M. ovum is unknown, comparison with M. wareni is not possible.

FIG. 93. Shell morphology and radula of species of Micratys Habe, 1952 . A, Micratys wareni n. sp., holotype MNHN 20435 (5 mm), ventral view, New Caledonia, BIOCAL stn CP 74; B, same shell, posterior view; C, radula of a paratype MNHN 20439, New Caledonia, BATHUS 1 stn CP 698, scale bar = 50 Μm. D, Micratys sp. 1 , (6 mm), posterior view, New Caledonia, BIOCAL stn DW 70; E, same shell, ventral view. F, Micratys sp. 3 , (1.5 mm) partial length, posterior view, New Caledonia, BIOCAL stn CP 57; G, same shell, ventral view. H, Micratys sp. 2 , (2.5 mm), posterior view, Fiji, MUSORSTOM 10 stn DW 1365; I, same shell, ventral view; J, same shell, detail of the sculpture, scale bar = 50 Μm.

ETYMOLOGY. — Dedicated to Anders Warén, Swedish Museum of Natural History, who collected many of the specimens studied herein.