The Cephalic Sensory Organ in Pelagic and Intracapsular Larvae of the Primitive Opisthobranch Genus Haminoea (Mollusca: Gastropoda)

Authors: Schaefer K.¹; Ruthensteiner B.²

Source: Zoologischer Anzeiger, Volume 240, Number 1, May 2001 , pp. 69-82(14)

Publisher: Urban & Fischer

Abstract:

This study provides a detailed description of the cephalic sensory organ (CSO) of four species of the cephalaspid genus Haminoea (Opisthobranchia, Gastropoda), based on light and electron microscopical investigations of complete serially sectioned larvae. The organ, which is present in all species investigated, exhibits the characteristic elements of gastropod CSOs: Two ciliary tuft cells; four to six ampullary cells showing intracellular lumina filled with bundles of tightly packed cilia; three para-ampullary cells interspersed medially and positioned laterally; a modified thickened microvillar border. A ciliary tuft is present in the planktotrophic developer Haminoea cymbalum, H. exigua and the intracapsular developer H. navicula, while it is lacking in the poecilogonous developer H. callidegenita. The number of ampullary cells ranges from 4 (H. cymbalum, H. exigua) to 6 (H. navicula, H. callidegenita). In general no clear correlation of development mode (e.g. planktotrophic vs. intracapsular) and organization of the organ can be found. Most structures, except ciliary tufts and number of ampullary cells, are very similar among the investigated species. The CSO cells of Haminoea are compared with those of other gastropods in the literature. The organ as a whole as well as its cellular components of Haminoea can clearly be homologized with such structures in other gastropods. The CSO's relationship to apical organs with regard to homology and the function is discussed.

Keywords: Veliger; Larval organs; Nervous system development; Developmental modes

Language: English

Document Type: Original article

Affiliations: 1: Zoologisches Institut der Universität Wien, Austria 2: Zoologische Staatssammlung München, Germany

Publication date: 2001-05-01

• In this: publication
• By this: publisher
• In this Subject: Zoology
• By this author: Schaefer K. ;  Ruthensteiner B.

Website © Publishing Technology. Article copyright remains with the publisher, society or author(s) as specified within the article.

• Terms and conditions
• Privacy policy
• Information for advertisers