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

The sculptural pattern of seven Caribbean species of Chicoreus (Siratus) [C. (S.) formosus (Sowerby, 1841), C. (S.) cailleti (Petit de la Saussaye, 1856), C. (S.) ciboney (Clench & Pérez Farfante, 1945), C. (S.) articulatus (Reeve, 1845), C. (S.) consuela (Verrill, 1950), C. (S.) perelegans Vokes, 1965 and C. (S.) guionneti n. sp.] is analysed, with special reference to the spiral characters and their topological correspondence. The primary cords IP, P1-P6, adp and mp, consistent in their place and their frequency, constitute the main architecture of the spiral sculpture, which is crossed by protovarices (continuous growth), then by varices and intervarical ribs (episodic growth). The intersection points between the axial and spiral sculptures (spines and nodules) show a canalized variability, the P1, P3, P5 and mp spines regularly being more developed than P2, P4, and adp spines, and the P1 and P2 nodules being broader than the other ones. The relief of cords (primary and secondary) and the nodules, the development of the spines and the number of the intervarical ribs may vary following different ontogenetic trajectories generating peculiar character associations, useful for the specific identifications. The character association distinguishing the new described species C. (S.) guionneti n. sp., from french West Indies, is: fine and narrow primary and secondary cords, ABP and EABP absent, low and well-individualized nodules, broader on P1, irregular browner zones between P1-P2, P4-P5, and P6-s6, low intervarical ribs, varices without basal foliation and lecithotrophic protoconch.