Atya innocous occurs in permanent and temporary freshwater streams in Panama. Its microhabitat distribution depends in part on the presence of congeners. The propodus and dactylus of each cheliped of A. innocous bear about 300 setae modified for specific functions in food collection. These setae may be divided into three basic types: chemoreceptors, scrapers, and filtering setae. The latter two types also function as mechanoreceptors. The cheliped setae are probably extended by hemocoelic pressure, producing an efficient filtering fan. Mechanosensory and chemosensory bipolar neurons innervate the cheliped setae, presumably providing the shrimp with the ability to detect current velocity, particulate load and food sources. The external morphology and ultrastructure of these sensilla are described. / The peropods are also used to groom body parts and brooded embryos. Super-8 cine films show the role mouthparts play in grooming. The third maxillipeds groom the antennae and antennules of the prawn, with the distal endite of the second maxillipeds freeing lodged debris from pereopods one and two. The pectinate comb of the fifth pereopod grooms the dorsal surface of the abdomen and pleopods. / Electron microscopy showed pores leading to unicellular glands within the epidermis. Three gland types were observed and their respective functions described. / Adaptations for a lotic habitat seem to have dominated atyid evolution. With the exception of lake species, most atyid shrimp have a wide array of morphological modifications for life in running water. / The mouthparts, mandibles and foregut of Atya innocous and another atyid Potimirim glabra are compared to test the hypothesis that these structures are related to diet. Potimirim glabra inhabits quiet pools scraping periphyton from leaf surfaces and decaying organic detritus. The feeding appendages of both species are modified for handling fine food. The mandible of these shirmp have a strong incisor and molar process but are not utilized for crushing large food items. The primitive nature of the mandibles and foregut suggest the placement of the family Atyidae at the base of the caridean evolutionary tree. / Source: Dissertation Abstracts International, Volume: 43-12, Section: B, page: 3877. / Thesis (Ph.D.)--The Florida State University, 1982.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_75016 |
| Contributors | FELGENHAUER, BRUCE EUGENE., Florida State University |
| Source Sets | Florida State University |
| Detected Language | English |
| Type | Text |
| Format | 150 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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