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The Proboscis Armature of Turbellaria‐Kalyptorhynchia, a Derivative of the Basement Lamina?
Author(s) -
Rieger Reinhard M.,
Doe David A.
Publication year - 1975
Publication title -
zoologica scripta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.204
H-Index - 64
eISSN - 1463-6409
pISSN - 0300-3256
DOI - 10.1111/j.1463-6409.1975.tb00715.x
Subject(s) - biology , basement membrane , proboscis , lamina , anatomy , turbellaria , epidermis (zoology) , lamina lucida , ultrastructure , basal lamina
The fine structure analysis of the proboscis teeth in the genus Carcharodorhynchus Meixner and of the proboscis hooks in the genus Diascorhynchus Meixner revealed that these structures are not derived from local cuticularizations of the epidermis, but rather are closely associated with the basement lamina of the proboscis sheath epithelium. In Diascorhynchus the hooks are specializations within the basement lamina enclosing the proboscis. The proboscis teeth in Carcharodorhynchus seem to be either an intracellular differentiation within the modified proboscis sheath epithelium or, as in Diascorhynchus , a derivative of the basement lamina. The latter is supported by the finding of similar, dermal teeth clearly derived from the basement lamina in the body wall of several species of the genus Carcharodorhynchus. It appears from this study that most “cutic‐ular” differentiations of the body wall in Turbellaria are either derivatives of the basement lamina or of the cytoplasm of the epidermis cells. These considerations are discussed in the light of possible evolutionary pathways leading from a ciliated epidermis (e.g. free‐living acoelomates) to a cuticularized hypodermis (e.g. Aschelmimhes and Articulata).