Species Dive 2 – Desmognathus pascagoula: Muddy wetland endemic

For the first species in the spotlight for 2023, I decided to talk about one of the newest additions to biodiversity we know of in Mississippi. Desmognathus pascagoula, the Pascagoula Dusky Salamander, is the newest amphibian (described in 2022 by Pryon et al.) we know to inhabit Mississippi.

This salamander was formerly a known as a member of the southern dusky species group, Desmognathus cf. auriculatus (Means et al., 2017; Beamer and Lamb, 2020; Pyron et al., 2022). In 2017, animals of this group were split into a western species, Desmognathus valentinei. After further analysis into their genetics and morphology, D. valentinei was discovered to be two distinct species. This newest species, Desmognathus pascagoula is a medium-bodied dusky salamander found in coastal swamps of small parts of Mississippi and Alabama.

An adult Pascagoula Dusky Salamander found in a muddy floodplain swamp in southeast Mississippi
A smaller D. pascagoula with less bright postocular mark but with distinct portholes

I had the fortune of searching for this species with a passionate group of southeastern herpetologists in early 2022. At that point in time, this species was not formally published but a few well-informed members of the group knew of its impending description. They reached out to me as a local in coastal Mississippi who might know of where to find their preferred habitat: muddy, mucky floodplains in a specific part of the southeastern corner of the state. Their habitat is similar to D. valentinei, another muddy wetland-dweller from piney ecosystems in a separate regional watershed. Surely enough, I had a decent spot in mind and these two individuals of D. pascagoula I photographed above were from a successful outing with the cohort once they visited (due to the sensitivity of this species’ habitat, I’ll refrain from disclosing more detail on where and when we searched for them).

A small sandy seepage adjacent to a muddy wetland (left in image), home to D. pascagoula

Little is known about this “narrowly endemic species of swamp-dwelling dusky salamander” (a direct quote from the title “A new, narrowly endemic species of swamp-dwelling dusky salamander (Plethodontidae: Desmognathus) from the Gulf Coastal Plain of Mississippi and Alabama” by Pyron, O’Connell, Lamb, and Beamer, 2022). The authors suggest it surely exists in a wider range than was described in their article. Its cryptic nature made it difficult for them to search for and efforts were very seasonally dependent. Specimen from purportedly extirpated sites remain in part a mystery; they are older and preserved in ways that disallow genetic analysis but have many of the morphological characters of D. pascagoula.

Since these similar specimen are from areas where extensive sampling took place without any results, it is suggested their historic range may have constricted slightly. Pascagoula Dusky Salamanders are currently only known from six sites within four counties (three in MS, one in AL). Fortunately, many of their habitats are within the bounds of protected state and federal wildlands, and their local abundance eases concerns for strict regulation or protection. The future will tell if more populations can be discovered and if their habitat suffers from the combined effects of climate change and human land development. See below for more photos and similar species!

D. cf. conanti a species found in adjacent but different microhabitats (sandy streams and seepages) at the same sites as D. pascagoula
D. valentinei, a species that varies only slightly in coloration and pattern, found in similar habitats of a separate watershed west of D. pascagoula
Belly pattern of adult D. pascagoula, held briefly in a plastic bag for safe handling.

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