Polycera Cuvier, 1817

Vallès, Yvonne, Valdés, Ángel & Ortea, Jesús, 2000, On the phanerobranch dorids of Angola (Mollusca, Nudibranchia): a crossroads of temperate and tropical species, Zoosystema 22 (1), pp. 15-31 : 22-24

Genus Polycera Cuvier, 1817

TYPE SPECIES. — Doris quadrilineata Müller, 1776

Polycera hedgpethi Er. Marcus, 1964 ( Figs 6 ; 7A )

Polycera hedgpethi Er. Marcus, 1964: 128-131 , figs 1-4.

MATERIAL EXAMINED. — Luanda Province. Corimba , 08˚49’S, 13˚13’E, 26.VI.1983, 1 specimen 7 mm preserved length ; 2 specimens 9 mm preserved length.

DISTRIBUTION. — This species has been reported from California, South Africa, New South Wales, Victoria and New Zealand, and more recently from Baja California, Mexico (see Behrens 1991) and Italy (see Cervera et al. 1988). These specimens are the first record from Angola.

DESCRIPTION

The background body colour is white in the living animal, covered of black points that give it a dark appearance ( Fig. 6 ). The oral veil digitations are white with a yellow ring in the middle area. Black spots are present over the entire lateral papillae except the apices, which are white. The rhinophores are white with numerous small black spots and have two yellow rings (one at the apex and another near the base). The oral tentacles are white with small yellow spots. There are eight white branchial leaves with numerous black spots, except for the rachis, and yellow spots on the borders. There is one extrabranchial process on each side of the gill, which is white with black and yellow spots. A small tubercle is present on each side, just anterior to the extrabranchial processes. On the left side of one animal the extrabranchial process has a malformation on its posterior part. The side of the animal is translucent white. The dorsum is covered with conical tubercles, some of them with yellow tips. A white line edges the mantle margin on each side of the dorsum, joining together in a single line behind the gill. This line continues to the posterior end of the foot, which is yellow with some black spots and a large conical tubercle near the tip.

The radular formula is 11 × (3.2.0.2.3) in a 9 mm specimen. The innermost lateral tooth is smaller than the second, having both a rectangular peak shape ( Fig. 7A ). The innermost lateral tooth is narrow at the base, and has a bulge in the middle. There are three outer lateral rectangular teeth, which decrease in size from the inner to the outermost.

REMARKS

Marcus (1964) described Polycera hedgpethi Marcus, 1964 as being a “grey color background animal with small black dots, with yellow-orange marks on the rhinophores, corners of the foot, and on the velar and extrabranchial appendages; streaks of the same color are seen on the pallial ridge, caudal crest, and upper border of the foot, and yellow orange spots are present on the widely spaced tubercles all over the body”.

Our specimen from Angola has a white background body colour that may appear grey (as Marcus observed in his specimen) due to presence of small black dots on the whole body. As mentioned before, our specimen has small yellow spots on the rhinophores, corners of the foot, on the velar appendages and on the lateral papillae. However, like Gosliner’s (1987a) specimen of P. hedgpethi from South Africa, our material from Angola has no orange spots. The tail has yellow pigmentation, and the tubercles are pigmented with yellow. The branchial leaves in the African material have a yellow pigmentation on their bor- der, differing from Marcus’ material which have the same colour as the rest of the body. On the other hand, the radular teeth morphology is very similar between Marcus’ and our material, and we consider that the differences in coloration mentioned above could be due to differences in size (Marcus’ specimens reached 16-20 mm preserved length, and our specimens are 7-9 mm preserved length).

Figures

FIG. 6. — Polycera hedgpethi (MNHN), dorsal view of the living animal. Scale bar: 1 mm.

FIG. 7. — Radular teeth morphology; A, Polycera hedgpethi (MNHN); B, Polycera aurantiomarginata (MNHN); C, Thecacera pennigera (MNHN). Scale bar: 100 µm.