Corolla spectabilis Dall, 1871
[dubious species]
Overview
This is a shell-less pteropod with a large gelatinous slipper-like pseudoconch, 4 cm long. The pseudoconch is broadly ova. The wings are disc-shaped and the visceral mass forms a dark nucleus embedded in the perfectly transparent pseudoconch. The pseudoconch is rounded at both sides and covered with large warts. The proboscis is prominent. It is an elegant swimmer that feeds with a mucous web on microplankton. It lives in the W-Atlantic and E-Pacific Oceans (Corolla spectabilis).
Taxonomic Description
The pseudoconch is slipper-shaped, with numerous small rounded tubercles which are smaller and closer together towards the posterio-dorsal side. The aperture is wider than in Corolla ovata, but nearly identical to that of Corolla calceola. The cavity extends into the dorsal apex of the "slipper". The swimming disc is broadly rounded to quadrangular, sometimes with two depressions in the posterior margin. In the original description a trilobed appearance of the disc is described, which is not confirmed by other authors. The disc is translucent and yellowish. The swimming disc protrudes far posterior of the pseudoconch border. The proboscis is free from the upper surface of the swimming plate to a point immediately in front of the central nervous system. Lateral foot appendages, forming the corners of the proboscis, are rounded. Tentacles are symmetrical. Small mucous glands are found along the border of the swimming plate. The mantle gland shows one complete and two incomplete transverse transparent bands, the gland is slightly asymmetrical.
Pseudoconch length is up to 40 mm, its width up to 25 mm. Diameter of the swimming disc up to 80 mm.
Juveniles
A special description is not available.
Reproduction
This species is a protandric hermaphrodite.
Ecology
This species is phytophagous and epipelagic. A preference for particles > 10µm seems to occur, for feeding and food see also Gleba cordata.
Distribution
Corolla spectabilis shows considerable diurnal vertical migration; in the Florida Current Wormelle (1962) found a mean day level at 221 m and a mean night level at 52 m. The distribution is typical as it is one of the few species restricted to the West Atlantic and East Pacific. This suggests a discontinuous range due to the closing of the Panama isthmus. It is, however, questionable if this species is of a geological age which makes such influences possible. Recently it was also reported from the Mediterranean (Berdar et al. 1982), see the Corolla spectabilis map.
Types
Corolla spectabilis Dall, 1871: 137.
Type not found.
Type locality: 42°50'N 147°25'W. Coll.: Dall, reg. no. 307.
Original description
Pinnæ broadly rounded, two small indentations in the upper portion, giving it a trilobed appearance, rather than transverse, translucent yellowish, speckled with black dots on the upper margin; crossed from one side to the other by arched, broad bands of muscular fiber, which are reticulated by similar radiating bends. A deep, broad sinus separates the pinnæ from the parts surrounding the mouth. The orifice of the latter is trumpet-shaped, situated in a transverse cleft of the membranes which surround it and which are roundly produced on each side of it like the lower portion of a pea-blossom. Îsophagus slender, bright yellow. The neck, by which the body hangs, is constricted, giving it a vase-like appearance. The intestines are variously tinted with brown, purple and green. Lon. of body.5; total lon., 2.0 in. Width of pinnæ, 1.8; height of do. 1.1 in.