Biology ETDs

Publication Date

7-13-1972

Abstract

Plethodon neomexicanus is a salamander endemic to the Jemez Mountains of New Mexico. Only about 10 localities are known, and in the study area one salamander occupies about 10 m2.Adult females are significantly larger than adult males, and the sex ratio is about one for the entire active season which extends from early June to early October. Sexual maturity is reached after 2 to 3 years in males and after 3 years in females. The diurnal ecological maximum and minimum temperatures are 17.0 and 6.0 C, respectively, with an average habitat temperature of 12.2 C. Most of the population is underground, but when surfaced most are found under logs with the greatest activity during the rainy months of July and August. The testis is an elongated cylinder with 47.4% having a caudal appendage. The basic unit of the testis is the lobule which surrounds a central longitudinal collecting duct in a radial fashion. The reproductive cycle begins in late autumn with the production of secondary spermatogonia. The cycle is most active during the summer, and spermatozoa probably occupy the entire testis by November. Sperm retention in females is permitted by the spermatheca; sperm are not retained after oviposition to any great extent. Females oviposit every other year and only gravid females take part in mating which takes place during July and August. Eggs are light yellow and are attached by a stalk. One clutch contained seven eggs with an average diameter of 6.9 mm. Oviposition probably occurs in the spring but may take place between August and the following spring. Hatching commences in mid- to late July.

Language

English

Document Type

Thesis

Degree Name

Biology

Level of Degree

Masters

Department Name

UNM Biology Department

First Committee Member (Chair)

William George Degenhardt

Second Committee Member

Clarence Clayton Hoff

Third Committee Member

Clifford Smeed Crawford

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