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The Structure of the Gular Pouch of Mature Males of the Lamprey Geotria australis
Author(s) -
Potter I. C.,
Welsch U.
Publication year - 1997
Publication title -
acta zoologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.414
H-Index - 37
eISSN - 1463-6395
pISSN - 0001-7272
DOI - 10.1111/j.1463-6395.1997.tb01131.x
Subject(s) - pouch , anatomy , biology , dermis , lamprey , extracellular matrix , distension , microbiology and biotechnology , medicine , surgery , fishery
Males of the southern hemisphere lamprey Geotria australis develop a large gular pouch during sexual maturation. The wall of this pouch contains (I) an epidermis comprising typical lamprey epidermal cells, (II) a thick dermis consisting of layers of collagen fibres, with intervening oxytalan fibres, and a vascular network, and (III) a hypodermis. The hypodermis contains active fibroblasts embedded in an extracellular matrix, comprising collagen fibrils, some of which form dense bundles, together with oxytalan fibres and an amorphous material that contains glycosaminoglycans. The hypodermis also contains arteries, which are innervated and confluent with a large anastomosing system of sinuses. Since these sinuses open at intervals into the large central cavity of the pouch, it is proposed that, at maturity, they discharge blood into the central lumen of the pouch, thereby causing the pouch to become distended. The degree of such distension would be regulated by the limited elasticity of the dermal collagen fibres. The dermis is thickest in those regions where the pouch is most susceptible to abrasion. The Weibel–Palade bodies, which are abundant in the sinus endothelia, may facilitate tissue repair where neccessary. The gular pouch is thus a specialised structure, which may play a role in courtship or the spawning act.