DRAFT Biological Status Review Report Striped Newt March 11, 2021 FLORIDA FISH AND WILDLIFE CONSERVATION COMMISSION 620 South Meridian Street Tallahassee, Florida 32399-1600 DRAFT Biological Status Review Report for the Striped Newt (Notophthalmus perstriatus) March 11, 2021 EXECUTIVE SUMMARY The Florida Fish and Wildlife Conservation Commission (FWC) was petitioned by Anna Farmer on March 12, 2019 to list the striped newt (Notophthalmus perstriatus) as Threatened. Furthermore, the petitioner requested that if the striped newt failed to meet the listing criteria for Threatened, that western populations (referred to as the panhandle population in this report) be evaluated separately because recent genetic evidence suggests they are a separate evolutionarily significant unit from eastern populations. The members of the Biological Review Group (BRG) met on June 26, 2020. Group members were Kevin Enge (FWC lead), Aubrey Greene (FWC), Steve Johnson (University of Florida), Ryan Means (Coastal Plains Institute), and Dirk Stevenson (Altamaha Environmental Consulting) (Appendix 1). In accordance with rule 68A- 27.0012, Florida Administrative Code (F.A.C.), the BRG was charged with evaluating the biological status of the striped newt using criteria included in definitions in 68A-27.001, F.A.C., and following protocols in the Guidelines for Application of the IUCN Red List Criteria at Regional Levels (Version 3.0) and Guidelines for Using the IUCN Red List Categories and Criteria (Version 8.1). Information on the listing process and criteria for listing as defined in rule can be found at https://myfwc.com/wildlifehabitats/wildlife/listing-process/. The BRG concluded from its biological assessment that statewide the striped newt met 2 criteria for designation as a Threatened species. Prior to completing the statewide assessment, the BRG opted to conduct a separate biological assessment of the panhandle population, in case subsequent input and review of its findings conclude that the striped newt as a species does not meet any of the criteria for listing as Threatened. The BRG determined that the panhandle population of the striped newt met 4 criteria for designation as a Threatened population. FWC staff recommends the statewide population of the striped newt be listed as a Threatened species. Independent scientific review of the initial draft of the biological status review (BSR) report was sought and received from 3 scientists. All reviewers agreed that the striped newt meets criteria for listing as Threatened at a statewide level. Information and comments provided by peer review have been incorporated into this document. For a summary of peer reviewer comments, see Appendix 2. FWC staff gratefully acknowledges the assistance of the external BRG members and BSR report peer reviewers, C. Kenneth Dodd Jr., Sarah May, and Lora Smith. The BRG in turn thanks Robin Boughton, Craig Faulhaber, Brad Gruver, Kelly O’Connor, Bradley O’Hanlon, Natalie Montero, Dan Sullivan, and Claire Sunquist for their guidance and assistance. Striped Newt Biological Status Review Report 2 BIOLOGICAL INFORMATION Taxonomic Classification – The striped newt (Notophthalmus perstriatus) was formally described by Bishop (1941) as Triturus perstriatus from specimens collected in Alachua and Leon counties, Florida, and Charlton County, Georgia. Carr (1940) referred to the striped newt as Triturus viridescens symmetrica (Harlan). Based on mitochondrial DNA (mtDNA) analyses of concatenated ND4 and 16S genes, and a separate analysis of the Cytochrome-B gene, the striped newt is sister to Florida specimens of the eastern newt (N. viridescens) (Matthew Fedler, FWC, pers. commun. 2020). This contradicts allozyme-based findings of Reilly (1990), who claimed that the striped newt is phylogenetically more closely related to the black-spotted newt (N. meridionalis) from southern Texas and Mexico than to the sympatric eastern newt. Several recent studies of salamander phylogeny found that results from allozyme analysis were inconsistent with those from modern DNA sequencing and analysis (Smith et al. 2018, Joyce et al. 2019). A study of mtDNA variation found that striped newt populations occur in 2 disjunct geographic regions (separated by approximately 125 km) that comprise separate evolutionarily significant units (May et al. 2011). Although these 2 regions do not share haplotypes, they have not genetically diverged sufficiently to represent separate species (Johnson 2002a, May et al. 2011). Since then, the species has been found in Taylor County, Florida, narrowing the purported distributional gap (Mays and Enge 2014), and the low-lying region along the Aucilla River apparently separates the eastern and western lineages (i.e., clades) in Florida. The Aucilla River also separates genetic lineages of the gopher frog (Rana capito) (Enge et al. 2017), which uses similar upland and wetland habitats. Studies of microsatellites and single nucleotide polymorphisms (next generation sequencing or ddRADSeq) supported genetic differentiation between eastern and western sites and found an overall pattern of isolation-by-distance (Farmer et al. 2018, Hoffman et al. 2019). Genetic clusters were present in the eastern clade in both states and in the western clade in Florida, but no gene flow existed between western clade sites in Georgia (Hoffman et al. 2019). Hereafter, the western clade will be referred to as the panhandle population and the eastern clade as the peninsular population in Florida. Life History and Habitat Requirements – Information on the species has been summarized by Dodd et al. (2005) and Enge (2019). Terrestrial adults typically migrate to breeding ponds during rains in fall and winter (some newts may migrate in spring or summer), and courtship, breeding, and oviposition occur in the water (Johnson 2002b). During the breeding season, male newts deposit spermatophores on the substrate that are subsequently picked up by female newts in their cloaca (Petranka 1998), A female may take several months to lay all her eggs (Johnson 2005), which are attached singly or in small clumps to aquatic vegetation or other objects (Carr and Goin 1955). When a larva is ca. 6 months old and measures 1.8‒3 cm snout-vent length (SVL), it either changes into an eft or remains in the pond until maturing ca. 6 months later into a paedomorph (Johnson 2002b). Efts are terrestrial juveniles, and paedomorphs are gilled adults. Sexual maturity is reached at ca. 2.5 cm SVL (Johnson 2002b). At a breeding pond in northern peninsular Florida, larvae required a minimum hydroperiod of 139 days before metamorphosing into efts (Dodd 1993). In another ephemeral wetland at the same site, Johnson (2002b) found that a striped newt paedomorph apparently only breeds once before transforming into a terrestrial adult (Johnson 2002b). This differs from other neotenic salamanders, including the mole salamander (Ambystoma talpoideum), that typically continue breeding as paedomorphs as long as water remains in the wetland. Based on the Striped Newt Biological Status Review Report 3 presence of populations of paedomorphic striped newts in permanent wetlands situated in presumably unsuitable upland habitats, such as dense sand pine (Pinus clausa) scrub, paedomorphs may exhibit reproductive plasticity. Non-gilled aquatic adults have never been found in these scrub wetlands (Kevin Enge, FWC, pers. obs.), suggesting the absence of terrestrial life stages. Additional evidence supporting the possibility of multiple reproductive episodes by paedomorphs in at least some populations is the wide variation in size of paedomorphs observed in some ponds, indicating that some paedomorphs are likely older than 1.5 years. Also, striped newts maintained in captivity in totally aquatic environments may breed more than once while retaining their gills (Mark Mandica, Amphibian Foundation, pers. commun. 2020). Little is known regarding feeding habits of terrestrial adults and efts. Aquatic adults opportunistically feed upon frog eggs, fairy shrimp, spiders, and larval and adult insects (Christman and Franz 1973, Dodd et al. 2005). Striped newts are primarily found in xeric upland habitats, most often sandhill but also in scrub, scrubby flatwoods, and adjacent mesic flatwoods. In Osceola County, Florida, newts apparently use mesic flatwoods and dry prairies besides patches of scrub and scrubby flatwoods (Enge et al. 2020). Primary upland habitats around 111 striped newt ponds in Florida were sandhill (59.5%), scrub (16.2%), scrubby flatwoods (7.2%), mesic flatwoods (7.2%), upland pine forest (4.5%), dry prairie (1.8%), xeric hammock (1.8%), and disturbed (1.8%) (Kevin Enge, unpubl. data). Habitat types are based on the Florida Cooperative Land Cover Map (version 3.0). Striped newts are rare or absent in unburned sandhills that have been invaded by hardwoods (Greenberg et al. 2003). Striped newts migrating from a pond favored the direction leading to sandhill habitat and were found up to 709 m from the nearest wetland (Dodd and Cade 1998). Johnson (2003) found that 16% of striped newts in his study migrated more than 500 m from ponds. Little is known regarding the terrestrial existence of efts and adults, although newts (primarily efts) are occasionally found under logs (Enge 2019). Striped newts typically breed in ephemeral or semipermanent sinkhole ponds, marshes, dome swamps, and borrow pits that lack large, predatory fish species (Christman and Means 1992, Dodd et al. 2005, Enge et al. 2014a) and have diverse herbaceous vegetation,