Ovarian Egg Complements and Nests of the Two-Lined Salamander, Eurycea b. bislineata X cirrigera, From Southeastern Virginia

Abstract

Recent study of the large ovarian egg complement of Eurycea bislineata rivicola Mittleman, by Wood and Duellman (1951:181), showed that gravid females may contain as many as 92 eggs ready for laying prior to the beginning of the nesting season. The maximum number reported in a nest deposited by one female, 50 eggs (H. H. Wilder 1899:235), is far short of the maximum number of larve ova present in some gravid females. Although Wilder (ibid) was referring to the eastern subspecies, E. b. bislineata (Green), this difference raises the question of the relationship reported to exist between number of ovarian eggs and the number of eggs in nests. I. W. Wilder (1924:77) observed that the number of eggs in nests of bislineata is consistent with the numbers of large ova in gravid females from the same region. Reported here are the numbers of large ova in 41 gravid females, and the number of eggs in 29 nests of the two-lined salamander, Eurycea b. bislineata X cirrigera. Females and nests were collected from the same regions on the Virginia coastal plain, principally in the vicinities of Yorktown and Williamsburg. The females were collected from springs and seepages during the winter months (largely January and February) in 1949, 1950, and 1951. These specimens were promptly preserved, and the ovaries were dissected out after hardening. The ovaries contained large yellowish yolk-filled ova, (1.5 to 2.5 mm in diameter) and small white translucent ova (0.3 to 0.75 mm in diameter). Intermediates between these two size-groups of ova were not noted, and only large ova were counted. The 41 females contained a total of 2,931 large ova, with complements ranging from 29 to 115, mean 71.5 ? 20.8 Snoutvent measurements were based on the straight-line distance from the anterior tip of the snout to the inner posterior margin of the cloaca. The females ranged in snout-vent length from 36 to 50 mm, mean 43 ? 3.4. Length measurements were plotted against counts of ova (fig. 1). The correlation between snout-vent length and the number of large ova was evaluated by the product-moment method. It was found that r = 0.695, t = 6.23, indicating that there is considerably less probability than one chance in several hundred that these data do not demonstrate a significant correlation. The number of large ova is related to the length of the female; generally, longer females contain more ova.