The anatomy of some new archaeogastropod limpets (Superfamily Peltospiracea) from hydrothermal vents
Article first published online: 23 MAR 2009
Journal of Zoology
Volume 218, Issue 1, pages 123–169, May 1989
How to Cite
FRETTER, V. (1989), The anatomy of some new archaeogastropod limpets (Superfamily Peltospiracea) from hydrothermal vents. Journal of Zoology, 218: 123–169. doi: 10.1111/j.1469-7998.1989.tb02530.x
- Issue published online: 23 MAR 2009
- Article first published online: 23 MAR 2009
- Accepted 26 May 1988
The anatomy is described of seven new species of limpet from hydrothermal vents in five new genera in the new family Peltospiridae, new superfamily Peltospiracea (McLean, 1989). Distinguishing external features are: (1) the tapering snout; (2) no eyes; (3) epipodium with tentacles variously modified; (4) deep mantle cavity; (5) single left bilamellate gill with pectiniform skeleton; (6) separate sexes; (7) no copulatory organ; (8) mantle edge with two folds, the outer secreting the shell with an inturned rim of periostracum, the inner sensory and differing in detailed structure of the secreting areas.
Limpet form is attained by the anterior migration of the posterior viscera into the mantle skirt on the right side. On the left is the single kidney, with monotocardian characteristics, followed posteriorly by the auricle and then the ventricle (not traversed by the rectum), which marks the posterior limit of the mantle cavity. The auricle receives blood from a pallial as well as a ctenidial circulation. There is no right kidney but a pallial excretory organ opens right of the rectum.
The radula is rhipidoglossate. The alimentary canal resembles that of a primitive prosobranch though with an odontophore indicating more powerful action, a subradular organ protrusible through the mouth and held in position by the tapering snout, and paired oesophageal pouches providing the most voluminous cavity of the body.
The gonadial duct acts as a vesicula seminalis in the male, and in the female opens into the kidney, the external opening of which is, in this sex, urinogenital. A second, receptacular duct, pallial in origin, connects with the ovary, opening to the mantle cavity near the anterior limit of the shell muscle and receiving seminal fluid emitted from the pallial vas deferens. Sperm are discharged directly into the ovarian duct, viable ones are stored and effete ones digested. The anatomy indicates that fertilization is internal. A levator muscle regulates the position of the openings of the gonadial and receptacular ducts within the ovary. It originates alongside the median margin of the right limb of the horseshoe-shaped shell muscle.
Relationships with other vent limpets are discussed.