Cuthona reflexa, Miller, 2004

Miller, M. C., 2004, An appraisal of the identity of the New Zealand species of the aeolid nudibranch family Tergipedidae (Gastropoda: Opisthobranchia), Journal of Natural History 38, pp. 1183-1192 : 1189-1190

as Cuthona reflexa sp. nov. in Miller (1977)

Remarks

When discussing the Hawaiian specimens of C. perca, Gosliner (1979) determined that C. reflexa was similar enough to be conspecific. His decision was adopted by Behrens (1984), and uncritically by Spencer and Willan (1995), but not by Perrone (1995). At the time of preparing the tergipedid paper (Miller, 1977) I did not include a comparison of these two species considering them as being clearly separable. Not being convinced that these two species are the same, I have re-examined my notes, drawings and photographs of C. reflexa . As a result I maintain the separation of C. reflexa . The characters which distinguish C. reflexa from C. perca (in parentheses) are the cerata held in a very obvious S-shape (less defined flexure) and zoned colouring (figure 3) of the digestive diverticula (uniform), pre-pericardial ceratal clusters of up to four rows (two), transparent colourless to very pale yellow body wall without surface pigmentation or very occasionally a few scattered dots of opaque white on the tips of the tentacles and cerata (light orange, deep on the sides of the head, a blotch of brown or black on the top of the head, opaque white as two subapical bands on the cerata), a radular tooth that is a smoothly curved arch bearing short stout denticles (angular, even squarish, with slender denticles), a straight penial stylet (curved).

Behrens’ (1984, 1991) identification of his Lake Merritt aeolid (Behrens, 1991, photograph number 194 on p. 93), Cuthona sp. A . of McDonald and Nybakken (1980) and Cuthona sp. of McDonald (1983) as C. perca as described by Gosliner (1979) and Miller (1977, as C. reflexa ) obviously conflicts with my separation of these two species. It is my opinion that his colour photograph of C. perca and McDonald and Nybakken’s are not of C. reflexa , nor is the colour shown in these photographs and described like that of C. perca described by others (Marcus, 1958; Edmunds, 1964; Gosliner, 1979), there being no orange and brown or black pigment on the head. The radular tooth described ( McDonald, 1983, pp. 132 and 169, figure 123, as Cuthona sp. ) is a squat angular arch, not the high curved one of C. reflexa . Perrone (1995) in describing a specimen of C. perca from Italy was uncertain about the conspecificity of this specimen with C. reflexa . Though the specimen described by Perrone is similar to C. reflexa in possessing a semicircular shaped frontal veil and brown granular ceratal diverticula, it is more like C. perca in overall appearance, colour, shape, size and arrangement of the cerata, and shape of the radular teeth. The distinctive characters of C. reflexa are the short, moderately club-shaped cerata held in an S in up to four rows in the pre-pericardial cluster, light coloured middle zone of the ceratal diverticula, and high and smoothly curved arch and short stout denticles of the radular teeth. In Perrone’s specimen the cerata are slender, in up to three rows in the pre-pericardial cluster, the ceratal diverticula darker in the middle, and radular teeth short and angular with long slender denticles.

The Barbados specimens described as C. perca by Marcus and Hughes (1974) differ greatly in colour and radular tooth shape from the descriptions of this species based on specimens found elsewhere (Marcus, 1958; Edmunds, 1964; Gosliner, 1979; Perrone, 1995). Further specimens of the same species collected from Barbados some years later were determined as being different from C. perca and related species and thus described as a new species, Cuthona barbadiana Edmunds and Just, 1983 .