A Suture Method to Optimize the Condition of Snake Specimens in Herpetological Collections

摘要

Cryptic species are often difficult to study and recognize, especially when little morphological criteria are available to help distinguish between closely related species. Although congeners may be very similar in appearance, combining genetic analyses with differences in mating calls and breeding phenology may allow for new distinct species to be recognized and properly identified (Newman et al. 2012). Frogs within the genus Pseudacris are a good example of this. The Boreal Chorus Frog (Pseudacris maculata) and the Western Chorus Frog (P. triseriata) are two North American species that are extremely similar in size and coloration, which has created taxonomic confusion in the past (Platz 1989; Klaus and Lougheed 2013). To distinguish the two species, the ratio of the tibia length to the snout-to-vent length (SVL) has been used as a criterion of discrimination. Pseudacris triseriata has a slightly larger ratio of 42.6, whereas P. maculata has a ratio of roughly 39.3 (Smith 1956). With the two species so similar in size and shape however, tibia/SVL ratios could overlap and lead to species misidentification. An alternate identification criterion often used in the field is the playback of each species' display call during the breeding season. Although each species' song may initially sound very similar, P. maculata has been found to have a longer call with a lower pulse rate, whereas P. triseriata's call is much shorter and has double the pulse rate (Platz 1989).