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Feeding, digestion and food storage in two species of temnocephalid flatworms (Turbellaria: Rhabdocoela)
Author(s) -
Jennings J. B.
Publication year - 1968
Publication title -
journal of zoology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.915
H-Index - 96
eISSN - 1469-7998
pISSN - 0952-8369
DOI - 10.1111/j.1469-7998.1968.tb08574.x
Subject(s) - biology , turbellaria , sucker , prehensile tail , digestion (alchemy) , flatworm , gill , hindgut , anatomy , zoology , crustacean , body cavity , coelom , larva , ecology , midgut , fish <actinopterygii> , fishery , chemistry , chromatography
Histological and histochemical methods have been used to study feeding, digestion and food storage in two species of temnocephalid flatworms. Temnocephala brenesi , from Costa Rica, and T. novae‐zealandiae , from New Zealand, are ectocommensal on the gills of freshwater decapod crustaceans and feed on a variety of small aquatic organisms. The prey is captured by means of prehensile tentacles, and is either ingested intact or held to the mouth whilst the pharynx ruptures the integument to draw in the body contents. In both species the alimentary system is of the typical rhabdocoel form, with a doliiform pharynx and saccate intestine. The gastrodermis is differentiated into glandular and phagocytic components, with some of the gland cells subgastrodermal and embedded in the parenchyma surrounding the intestine. Digestion occurs by a combination of extra‐ and intracellular processes; endo‐ and exopeptidases, acid and alkaline phosphatases and lipases are secreted in sequence and can be demonstrated histochemically. Deposits of fat occur in the vitellaria and eggs, and glycogen is laid down in the testes and the musculature of the pharynx and sucker. The ectocommensal life has not caused any significant change in the general pattern of nutrition characteristic of free‐living flatworms and no tendency towards a parasitic existence has been found.