Changes in feeding mechanisms during early ontogeny in juveniles of Crepidula fecunda (Gastropoda, Calyptraeidae)
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Feeding in early life stages of the sedentary snail Crepidula is effected both by the use of the radula and by filtering with the gill. The present study is a contribution to the knowledge of the mechanisms of feeding by early juvenile snails of Crepidula fecunda. Experimental observations were made on specimens of known ages as they were fed constant concentrations of microalgae in the presence of a primary biological film on a glass substrate. Feeding activity was filmed under the microscope, and images were digitized for the identification and quantification of feeding structures. A morphological analysis was made of the structures associated with this process. Results showed that the radula was functional beginning in 1-day-old juveniles, and the gill functioned in respiration. Gill function in filter-feeding began in juveniles of 9 days old when dorsal and ventral ciliation had developed, as well as the food pouch. The latter structure begins activity as soon as the gill starts food collection. Osphradia appeared simultaneous with development of the filter feeding capacity by the gill. In their earliest stages after metamorphosis, the young snails begin life by radular scraping of primary biofilms, gradually shifting to filter feeding as the gill developed a critical number of filaments and cilia.
KeywordsShell Length Food Particle Gill Filament Isochrysis Early Juvenile
We thank Mr. R. Silva for his help with the SEM samples. This research was founded by Fondecyt - Chile (Grant 1020171).
- Cañete JI, Ambler RP (1992) Desarrollo intracapsular del gastrópodo comestible Calyptraea (Trochita) trochiformis (Born, 1778), en Chile. Rev Chilena Hist Nat 65:255–266Google Scholar
- Declerck CH (1995) The evolution of suspension feeding in gastropods. Biol Rev 70:549–569Google Scholar
- Hoagland KE (1979) The behavior of three sympatric species of Crepidula (Gastropoda: Prosobranchia) from the Atlantic, with implications for evolutionary ecology. Nautilus 94:143–149Google Scholar
- Hoagland KE (1986) Patterns of encapsulation and brooding in the Calyptraeidae (Prosobranchia: Mesogastropoda). Am Malacol Bull 4:173–183Google Scholar
- Hughes RN (1986) A functional biology of marine gastropods. Croom Helm, LondonGoogle Scholar
- Orton JH (1912) The mode of feeding of Crepidula, with an account of the current-producing mechanism in the mantle cavity, and some remarks on the mode of feeding in gastropods and lamellibranchs. J Mar Biol Assoc UK 9:444–478Google Scholar
- Orton JH (1913–1915) On ciliary mechanisms in brachiopods and some polychaetes, with a comparison of the ciliary mechanisms on the gills of molluscs, protochordata, brachiopods, and cryptocephalous polychaetes, and an account of the endostyle of Crepidula and its allies. J Mar Biol Assoc UK 10:283–311Google Scholar
- Purchon RD (1977) The biology of Mollusca. Pergamon Press, New YorkGoogle Scholar
- Putnam DA (1964) The dispersal of young of the commensal gastropod Crepidula adunca from its host, Tegula funebralis. Veliger 6:63–66Google Scholar
- Werner B (1951) Über die bedeutung der wasserstromerzeugung und wasserstromfiltration für die nahrungsaufnahme der ortsgebundenen meeresschnecke Crepidula fornicata L. (Gastropoda Prosobranchia). Zool Anz Bd 146:97–113Google Scholar