Morphometric and physical characteristics distinguishing adult Patagonian lamprey, Geotria macrostoma from the pouched lamprey, Geotria australis

QUIROGA , A. P.; KITSON, J.; POTTER, I. ; RIVA ROSSI, C. M.; WILLIAMS, P.; RENAUD, C.; BAIGUN,C.; BAKER, CINDY; WHITE, E.; BICE, C.; NEIRA, F.

PLOS ONE

PUBLIC LIBRARY SCIENCE

Lugar: San Francisco; Año: 2021 vol. 16

1932-6203

The pouched lamprey, Geotria australis Gray, 1851, has long been considered monotypic inthe Geotriidae family with a wide southern temperate distribution across Australasia andSouth America. Recent studies have provided molecular and morphological evidence for asecond Geotria species in South America; Geotria macrostoma (Burmeister, 1868). Theaim of this study was to determine morphometric and physical characteristics of adult G.macrostoma that further differentiate this re-instated species of Geotriidae from G. australis.The diagnostic features discriminating immature adult G. macrostoma from G. australiswhen entering fresh water, are distinct differences in dentition, oral papillae and fimbriaecounts and differences in coloration. In addition, G. macrostoma display greater growth ofthe prebranchial region and oral disc and has a deeper body depth and higher condition factor. All current ecological knowledge of the genus Geotria is based on Australasian populations, which may not be applicable to G. macrostoma. To ensure the conservation andprotection of the Patagonian lamprey as a re-identified species, further investigations areneeded to understand its life history, biology and ecology throughout its range.