Chicoreus (Siratus), Jousseaume, 1880

Merle, Didier, Garrigues, Bernard & Pointier, Jean-Pierre, 2001, An analysis of the sculptural pattern of the shell in Caribbean members of Chicoreus (Siratus) Jousseaume, 1880 (Gastropoda, Muricidae), with description of a new species, Zoosystema 23 (3), pp. 417-431 : 426-427

Subgenus Siratus Jousseaume, 1880

TYPE SPECIES. — Purpura sirat “Adanson, 1757 ” Jousseaume, 1880 by original designation (= Murex senegalensis Gmelin, 1791 ).

Chicoreus (Siratus) guionneti n. sp. ( Figs 4E ; 6F ; 7A, B ; 8B ; 9A, B )

Chicoreus (Siratus) sp. – Garrigues & Pointier 1997: 18, figs 11; 12.

TYPE MATERIAL. — Holotype, Marie Galante Island, Guadeloupe Archipelago, length 56.7 mm ( MNHN) Fig. 9A . Paratype, Martinique Island, length 37.8 mm ( MNHN) Fig. 9B.

TYPE LOCALITY. — Off southern Marie Galante Island, 200 m.

ETYMOLOGY. — Named in honour to Pierre Guionnet. OTHER MATERIAL EXAMINED. — Marie Galante Island. Three spm, coll. Garrigues & Lamy.

Martique Island. Three spm, coll. Garrigues & Lamy. OTHER LOCALITY. — 20 kilometers off Trinité, Martinique Island, 250 m.

DESCRIPTION

Paucispiral protoconch, diameter of 1.35 mm. Teleoconch globose, up to 56.7 mm in length, up to 25 mm in width excluding cord spines, and up to 30 mm in width including cord spines. Spire moderately high up to 6.5 subcarinate whorls. Last whorl (sixth whorl) up to 83% of total length of the teleoconch. Apical angle of 65°. Spiral sculpture with narrow primary cords. First and second whorl: presence of primary cords ip, P1, P2 and P3. Third whorl: appearance of the secondary cords adis on the sutural ramp and s1. Fourth whorl: appearance of the secondary cord s1. Fifth whorl: appearance of the secondary cords s2 and abis. Sixth and last whorl showing the primary cords IP (sutural ramp), P1 to P6 (convex part of the whorl), and ADP and MP (siphonal canal); fine secondary cords (s1-s6); s1-s4, finer than s5 and s6; tertiary cords present between P5 and s5, s5 and P6, P6 and s6, s6 and ADP. Axial sculpture with 13 protovarices on first whorl. On second whorl, appearance of three major varices and eight intervarical ribs (two or three between each major varix). On third whorl, seven intervarical ribs (two or three between each major varix). On the fourth, six intervarical ribs (two between each major varix). On the fifth whorls, seven intervarical ribs (two or three between each major varix). On sixth whorls nine intervarical ribs (three between each major varix). Major varices with moderately long and narrow spines. Spines P1, P3 and P5 longer than spines P2, P4 (both reduced) and P6. MP spine longer than adp spine. Spines of secondary cords not developed except s5 and s6. Intervarical nodules with low relief, but slightly higher on P1 than in other topological places. Aperture rounded, large and up to 40% of the diameter and up to 85% (including the siphonal canal) of length of the body whorl. Columellar lip with six weak, low knobs abapically. Rim partially erect, adherent adapically. Anal notch narrow, moderately deep. Parietal callus poorly developed. Inner denticles of the outer lip weak. ID more pronounced than the other inner denticles (D1-D6). Denticles at the edge of the outer lip (= crenulations) weak on convex part of the whorl and more marked on the shoulder particularly between the notch and adis, abis and IP, and IP and P1. Siphonal canal up to 64% of the aperture length and slightly recurved. Shell creamy to rosy-brown with brown lines on primary cords and interrupted by the intervarical nodules. Irregular browner zones between P1 and P2, P4 and P5, and P6 and s6. Animal, radula and operculum unknown.

INTRASPECIFIC COMPARISONS

The protoconch diameter varies from 1.29 mm (paratype) to 1.35 mm (holotype). On the teleoconch, the spiral sculpture of the other examined specimens shows a consistent pattern consisting in narrow primary cords (IP, P1-P6, ADP, MP), and in fine secondary cords, more developed between P4 and P5, P5 and P6 and between P6 and ADP. The intervarical nodules also are always small, wellindividualized and higher on p1 than on the other topological places; they are not present on the intersection points of the secondary cords. In all studied specimens, the P1, P3, P5 and MP spines are more developed than the P2, P4, P6 and ADP spines. The variation of the number of protovarices is: 13 to 16 on first whorl, and 10 to 13 on second whorl. The appearance of major varices and intervarical ribs is observed between the second and third whorl. The variation of the number of intervarical ribs is: six to nine on the third whorl, six to 12 on the fourth and fifth whorls, and 12 to 19 on the sixth whorl. In the aperture, the columellar lip can possess from two to six weak knobs.

Figures

FIG. 4. — Evolution of the tnv (total number of varices including protovarices and intervarical ribs), the NIR (number of intervarical ribs) and the LD [(LP1/D)*10], during the ontogenesis of the seven Chicoreus (Siratus) species. For each species, the mean is used.

FIG. 6. — Profile views of the intervarical nodules; A, Chicoreus (Siratus) ciboney (Clench & Pérez Farfante, 1945), Port-Louis (coll. Lamy), seven whorls; B, C. (S.) perelegans Vokes, 1965, Port-Louis (coll. Lamy), six whorls; C, C. (S.) consuela (Verrill, 1950), Port- Louis (coll. Lamy), seven whorls; D, C. (S.) articulatus (Reeves, 1845), Porto Rico (coll. Garrigues), seven whorls; E, C. (S.) formosus (Sowerby, 1841), Haiti (coll. Garrigues); F, C. (S.) guionneti n. sp., Martinique (paratype, MNHN); G, C. (S.) cailleti (Petit de la Saussaye, 1856), Saintes (coll. Lamy), seven whorls. Abbreviations: see text. Scale bars: 5 mm.

FIG. 7. — Spiral sculpture (apertural view), Chicoreus (Siratus) guionneti n. sp; A, Martinique (coll. Garrigues), five whorls; B, Guadeloupe (coll. Lamy), six whorls. For A, the siphonal canal is not completely drawn. Abbreviations: see text. Scale bars: 5 mm.

FIG. 8. — Protoconchs and first teleoconch whorl; A, Chicoreus (Siratus) ciboney (Clench & Pérez Farfante, 1945), Port-Louis; B, C. (S.) guionneti n. sp., Martinique; C, C. (S.) cailleti (Petit de la Saussaye, 1856), Saba bank; D, C. (S.) perelegans Vokes, 1965, Port-Louis; E, C. (S.) articulatus (Reeves, 1845), Puerto Cortes; F, C. (S.) consuela (Verrill, 1950), Port-Louis. Abbreviations: see text. Scale bar: 1 mm.

FIG. 9. — A, Chicoreus (Siratus) guionneti n. sp., holotype, MNHN (length 56.7 mm), Marie Galante; B, C. (S.) guionneti n. sp., paratype, MNHN (length 37.8 mm), Martinique; C, C. (S.) formosus (Sowerby, 1841), coll. Garrigues (length 63.9 mm), Haiti; D, C. (S.) articulatus (Reeves, 1845), coll. Garrigues (length: 62 mm), Porto Rico; E, C. (S.) ciboney (Clench & Pérez Farfante, 1945), coll. Lamy (length 53.8 mm), Saba Bank; F, C. (S.) cailleti (Petit de la Saussaye, 1856), coll. Lamy (length 60.1 mm), Guadeloupe; G, C. (S.) consuela (Verrill, 1950), coll. Lamy (length 57 mm), Guadeloupe; H, C. (S.) perelegans, coll. Lamy (length 58 mm), Guadeloupe.