Pecos pupfish  (Cyprinodon pecosensis)

Description

Once abundant and relatively widespread, today this Critically Endangered fish persists in small numbers at just a few isolated sites (3). The diminutive Pecos pupfish has a stout body with rounded fins, with the male larger than the female. Throughout most of the year, both sexes are a dull brownish-green and marked with a series of dark spots and blotches (2). However, during the summer breeding season the male undergoes a striking colour change (2) (4), becoming an iridescent greyish-blue with creamy gill covers and a dark bar along the rear border of the tail fin (2).

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