Description Description: Ambystoma bishopi is a moderately sized salamander species. The snout-vent length (SVL) of A. bishopi males ranges from 40.52-47.08 mm.Adult females have an SVL range of 41.09- 51.17 mm. 14 to 16 costal grooves are present. Tail width and height are sexually dimorphic characters, both of which are smaller in males (Pauly et al. 2007). The skin is smooth dorsally and ventrally, but is wrinkled on the flanks between the axilla and groin. The head is elongate. The snout is tapered. The nostrils are small and located towards the tip of the snout. Eyes are of medium size. A groove goes from the corner of the eye to behind the jaw base (Goin 1950).This species has vomerine teeth. However the arrangement and number are debated. Goin (1950) states the teeth are uniformly arranged into two rows while another study claims variable rows of teeth arrangement (Martof and Gerhardt 1965). The forelimbs are stout. The tail is flattened posteriorly and is shorter than the head and body lengths (Goin 1950).
Diagnosis: A. bishopi can be distinguished from A. cingulatum by its shorter limbs and smaller head (USFWS 2009). Generally, this species has fewer costal grooves than A. cingulatum and a shorter tail. The ventral pattern of A. bishopi consists of indistinct white spots on a dark background, creating a "salt and pepper" look, compared to A. cingulatum, which has distinct white spots on the ventral side (Goin 1950; USFWS 2009). The dorsal side pattern of A. bishopi is more net-like in appearance than the frosted patterning of A. cingulatum (USFWS 2009; Goin 1950).
Tadpole morphology: Larvae are less vividly marked and metamorphose earlier and at a smaller size than A. cingulatum (Goin 1950; Telford 1954). A. bishopi has several stripes either yellow brown or black along the body. Gills are bright red in life (Telford 1954).
A. bishopi and A. cingulatum larvae are difficult to distinguish (Martof and Gerhardt 1965). A. cingulatum larvae have broad, striped heads, with a black stripe extending from the nose to the gills and a second stripe along the upper jaw (Palis 1996). A light lateral stripe is retained in first year fully metamorphosed individuals, but is lost in older individuals (Palis 1997).
Coloration: The dorsal surface of A. bishopi is reticulated, with thin grey lines that form a net-like or banded pattern against a black to brown background (USFWS 2009). These lines surround areas of dark coloration (Martof and Gerhardt 1965). Small white flecks on a dark background cover the ventral surface, creating a "salt and pepper" pattern (Goin 1950). Preserved specimens of A. bishopi, can become dark, making their dorsal pattern unrecognizable (Martof and Gerhardt 1965).
Historically, A. bishopi was distributed west of the Apalachicola-Flint River, in the lower Gulf coastal plains of southern Alabama, Georgia, and Northern Florida (Pauly et al. 2007; Whiles et al. 2004). Currently, their known distribution includes portions of the Florida panhandle and southern Georgia, west of the Apalachicola-Flint River (Pauly et al. 2007). No members of this species have been found in Alabama since 1981 (Godwin pers. comm).
Habitat for mature salamanders consists of upland areas with few tress, typically longleaf pines, and grasses. Soil is poorly drained sand, which leads to seasonal ponds and damp surroundings. This habitat will often have an open overstory of widely scattered longleaf pine, little to no midstory, and a diverse community of low growing shrubs which include highly diverse forb and grass communities (Palis 1996).
Larval A. bishopi occupy acidic (pH 3.4 - 5.6) ephemeral wetlands. These wetlands have varying amounts of vegetation, and lack dense midstory growth. Canopy is comprised of a typical Florida wetland assemblage (Palis 1996).
Life History, Abundance, Activity, and Special Behaviors A. bishopi is a terrestrial, burrow-dwelling salamander that spends the majority of its life among the leaf litter. It emerges from the ground at night during periods of rain to breed (Palis 1996). These migrations have been linked to the presence of cold fronts. The breeding migration begins in October as heavy rains draw adults out (Palis 1997).
Females lay a number of eggs proportional to their size but may produce up to 225 eggs. Eggs are deposited either individually or in small groups beneath leaf litter, logs, shrubs, trees or at the entrance to crayfish burrows before breeding sites begin to fill up (Anderson and WIlliamson 1976; Palis 1996). Eggs may develop to hatching size within three weeks but will not actually hatch until flooded with water. Larvae are nocturnal, hiding most of the day, and feeding in a water column at night. Metamorphosis usually takes place beginning in March and ends in April (Palis 1996). Mature salamanders move to upland areas where they live until returning to ponds to breed (USFWS 2009).
Adults of A. bishopi have been known to consume earthworms while larvae feed on invertebrates, such as crustaceans, isopods (Caecidotea) and amphipods (Crangonyx) (Goin 1950; Whiles et al. 2004).
Trends and Threats Habitat loss from agricultural conversion or commercial development, pond alteration and additional introduction of predatory fish, fire suppression leading to altered forest habitat and crayfish harvesting comprise the most serious threats to A. bishopi populations (Palis and Hammerson 2008). One threat comes from the introduction of predators or disease to their small breeding pools from larger, permanent water sources via roadside ditches, tire ruts or other such manmade disturbances. "Red-leg" disease (Aeromonas hydrophila) is known to have affected A. talpoideum populations in breeding pools A. bishopi also historically occupied. Chytrid fungus (Batrachochytrium dendrobatidis) and a parasitic nematode (Hedruris siredonis) have also been associated with decreased larval fitness and mass die-offs in other Ambystomatid species, suggesting that they could also pose a threat to A. bishopi. An estimated 36 percent of all known populations have only one breeding pond that they use annually and any disruption could lead to a severe decline (USFWS 2009).
A. bishopi selectively breeds in open canopy, longleaf pines which are particularly fire-adapted. However, fire suppression may lead to changes in the coverage and wetland composition that this species selects for. Further growth could crowd the ecosystem and destroy historical breeding ponds (Bishop and Haas 2005). Though this has not been proven, the potential exists if no consideration is given.
Due to the burrowing nature of the species, adult population numbers are difficult to enumerate. However, no more than 10,000 adults in twenty populations are estimated within the entire range. The population is assumed to be declining rapidly given deforestation, silviculture, and general habitat degradation and fragmenting (Palis and Hammerson 2008).
Possible reasons for amphibian decline
General habitat alteration and loss Habitat modification from deforestation, or logging related activities Intensified agriculture or grazing Urbanization Disturbance or death from vehicular traffic Drainage of habitat Subtle changes to necessary specialized habitat Habitat fragmentation Local pesticides, fertilizers, and pollutants Disease
Comments Species Authority and Phylogenetic Relationships: A. bishopi was first described by Goin (1950) as Ambystoma cingulatum bishopi. Later this subspecies categorization was refuted by Martof and Gerhardt (1965) and was combined with A. c. cingulatum to form one species, A. cingulatumi. In 2007, A. bishopi was separated from A.cingulatum by Pauly et al. (2007) based on differences in mitochondrial DNA, morphology and allozymes. Because the two species were considered subspecies until 2007 and much of the life history information is assumed to be true for both species (USFWS 2009).