The following account is modified from Amphibian Declines: The Conservation Status of United States Species, edited by Michael Lannoo (©2005 by the Regents of the University of California), used with permission of University of California Press. The book is available from UC Press.

Ambystoma barbouri Kraus and Petranka, 1989
Streamside Salamander

Mark B. Watson
Thomas K. Pauley

1. Historical versus Current Distribution. The current range of streamside salamanders (Ambystoma barbouri) includes central and western Kentucky, central Tennessee, southeastern Indiana, southwestern Ohio, and western West Virginia along the Ohio River (Kraus and Petranka, 1989; Longbine et al., 1991; Petranka, 1998). Kraus and Petranka (1989) first described streamside salamanders as a sibling species of small-mouthed salamanders (Ambystoma texanum). Streamside salamanders and small-mouthed salamanders are allopatric throughout most of their range, but parapatric or sympatric in portions of Kentucky and Tennessee (Petranka, 1982b). Streamside salamanders can be distinguished from small-mouthed salamanders by differences in range, ecology, and slight morphological characters such as different dentition. For example, small-mouthed salamanders have maxillary and premaxillary teeth with long pointed cusps, whereas streamside salamanders have more rounded cusps similar to other ambystomatids. All reports prior to 1989 considered streamside salamanders to be stream-breeding small-mouthed salamanders. Therefore, changes in historical distribution may not be apparent. New populations of streamside salamanders may be discovered in the states within their range after a thorough examination of small-mouthed salamander specimens.
2. Historical versus Current Abundance. Reports of stream-breeding small-mouthed salamanders prior to the description of streamside salamanders as a separate species were probably of streamside salamanders. For example, Green (1955) stated that the only known population of small-mouthed salamanders in West Virginia breeds in streams. Subsequently, Longbine et al. (1991) showed that this population consists of streamside salamanders.
3. Life History Features.
A. Breeding. Reproduction is aquatic.
i. Breeding migrations. Streamside salamanders have an extended breeding season that lasts from late fall to early spring. Breeding migrations occur on rainy nights and individuals usually move from forests to first- and second-order streams, although streamside salamanders have been also found in ponds (Petranka, 1984a). Streamside salamanders do not migrate en masse as seen in congeneric species such as spotted salamanders (Ambystoma maculatum). Breeding in streamside salamanders begins 4–5 wk earlier than in small-mouthed salamanders where the species occur sympatrically. Additionally, streamside salamanders migrate to their breeding streams in the fall and undergo low levels of mating activity from early winter to early spring (Kraus and Petranka, 1989).
ii. Breeding habitat. Streamside salamanders were first described as a stream-breeding type of small-mouthed salamanders (Petranka, 1982a). They breed in first- and second-order streams that are usually devoid of fishes (Petranka, 1983, 1984d; Kats and Sih, 1992). Petranka (1982a) described the courtship behavior of stream-breeding small-mouthed salamanders in the laboratory. He described courtship in four phases. During Phase 1, males exhibited exaggerated undulations of their bodies and tails. They also circled in tight groups for 18–35 min. Phase 2 was described as spermatophore deposition, which lasted about 10 s. The males grasped the substrate with their legs and deposited 1–5 spermatophores on the top of gravel particles or other substrate. He also observed that males might try to dislodge spermatophores of conspecifics. In Phase 3, females entered a field of spermatophores. Females mounted 18–27 spermatophores, some more than once. During Phase 4, females became dormant or motionless and laid eggs within 48 hr. McWilliams (1992) observed that breeding activities of streamside salamanders and small-mouthed salamanders are similar and that the location for breeding is the major difference. McWilliams (1992) also noted that unlike small-mouthed salamanders, breeding streamside salamander males are less likely to interfere with other males.
B. Eggs.
i. Egg deposition sites. Eggs are attached in a single row on the lower surface of flat rocks in flowing streams (Petranka, 1984d). Subsequent rows of eggs may be deposited, which may form clumps. Eggs are usually deposited in hidden or cryptic sites but may be in exposed locations (Sih and Maurer, 1992). Egg deposition occurs from January to early April. Oviposition generally occurs in pools, as opposed to riffles, in streams (Petranka, 1984a; Holomuzki, 1991).
ii. Clutch size. While clutch size varies from < 10 to > 1,000 eggs, the average number of ova in gravid females is around 260, suggesting communal egg deposition (Petranka, 1984a,d).
C. Larvae/Metamorphosis. Petranka (1984d) and Petranka and Sih (1986) observed that eggs hatch during late April, and larvae transform 6–9 wk after hatching. Brandon (1961) described the larval development of stream-breeding small-mouthed salamanders from central Kentucky. Newly hatched larvae are 12 mm in length. Individuals begin to metamorphose at 37–41 mm. He also observed two individuals in that size range that had completely lost their gills. Petranka (1984c,d) noted that temperature and food availability could influence larval growth rates. At warm temperatures (24 ˚C) larvae metamorphosed in 27 d on average, but at cooler temperatures (15 ˚C) metamorphosis was delayed to an average of 72 d. He also noted that larvae grew to a larger size when metamorphosis occurred at cooler temperatures. Maurer and Sih (1996) compared larval growth rates of streamside salamanders and small-mouthed salamanders. Streamside salamanders showed increased feeding and activity levels and developed faster than small-mouthed salamanders. Streamside salamanders also reduced their activity in response to food deprivation. These differences were attributed to differences in habitat duration between the stream-dwelling and pond-dwelling species.
In some streams, competition for food may increase the length of the metamorphic period (Petranka and Sih, 1986). Chemical cues from green sunfish (Lepomis cyanellus) could delay hatching of streamside salamanders (Moore et al., 1996). Similarly, Sih and Moore (1993) reported experimental evidence to show that flatworm (Pagocotus gracilis) predation can induce streamside salamander eggs to delay hatching. Increased size of hatchlings decreased the likelihood of predation by flatworms.
D. Juvenile Habitat. Juvenile streamside salamanders utilize the same habitat as larvae. Streamside salamander juveniles feed on various macroinvertebrates, including insect larvae, zooplankton, isopods, and amphipods (Huang and Sih, 1990; Sparks, 1996).
E. Adult Habitat. Adult streamside salamanders are extremely fossorial and above ground activity is mostly observed during breeding migrations (Petranka, 1982a; Holomuzki, 1991). They are usually found in upland deciduous forests and are most common in regions with exposed limestone (Petranka, 1998).
F. Home Range Size. Unknown.
G. Territories. Unknown.
H. Aestivation/Avoiding Dessication. Aestivation is unknown; animals may seek shelter under cover objects or burrow when facing dessicating conditions.
I. Seasonal Migrations. Petranka (1984a) found that migrations to breeding sites in central Kentucky occur from late October to March. Males reach breeding sites before females (Petranka, 1984a).
J. Torpor (Hibernation). Unknown.
K. Interspecific Associations/Exclusions. Streamside salamanders breed in first- and second-order streams and may come into contact with individuals in the genera Desmognathus, Eurycea, Pseudotriton, and Gyrinophilus.
L. Age/Size at Reproductive Maturity. Unknown.
M. Longevity. Unknown.
N. Feeding Behavior. Streamside salamander larvae can have substantial effects on the density of benthic isopods. Huang and Sih (1991a) observed a large negative relationship between density of salamander larvae and isopods in stream experiments. Sih and Petranka (1988) showed that small-mouthed salamander larvae were not selective when prey items were in low abundance, but would release previously acquired smaller prey in order to acquire larger prey.
O. Predators. Fishes are the major predators of streamside salamander larvae. Petranka (1983) showed that fish predation or the presence of fish restricted stream-breeding small-mouthed salamander larvae to upper regions of streams that are devoid of fishes. Kats et al. (1988) demonstrated that stream-breeding small-mouthed salamanders were palatable to fish. Sih et al. (1992) reported that fish preyed heavily upon larvae of streamside salamanders. They observed that 30–40% of larvae drifted into a pool with fish, and of those only 6–8% survived to drift out. Sih (1992) suggested that ineffective predator defense against sunfish (Centrarchidae) may be important in the evolution of small-mouthed salamanders. Sunfish in stream pools could be a barrier to gene flow by preventing movement of larvae between pools (Storfer, 1999a). Populations of streamside salamanders separated by fish within the same stream could be as genetically different as those from different streams (Storfer, 1999b). Flatworms prey on small streamside salamander larvae in streams (Petranka et al., 1987a; Sih and Moore, 1993). Three small-mouthed salamander larvae and one mud salamander (Pseudotriton montanus) larva were regurgitated by a northern water snake (Nerodia s. sipedon) that was found foraging in a small stream in central Kentucky (Kats, 1986).
P. Anti-Predator Mechanisms. Adult small-mouthed salamanders, a close relative of streamside salamanders, use biting and immobility as anti-predator defenses. They also elevate the tail and roll their bodies toward a grasped limb, right themselves, and coil upon release (Brodie et al., 1974a; Brodie, 1977). Members of the genus Ambystoma have many anti-predator adaptations including tail movements, coiling and elevating the body, aposematic coloration, and noxious skin secretions (Brodie, 1977). Huang and Sih (1990) found stream-dwelling small-mouthed salamander larvae increased the use of refugia in the presence of predatory sunfish.
In laboratory studies that simulated fish predation, streamside salamanders took refuge under artificial substrates (Huang and Sih, 1991b). Several studies have shown that streamside salamander larvae respond to chemical cues from predatory fish. In these studies, larvae exhibited anti-predator behavior when fish were kept isolated and not visible to the larvae (Petranka et al., 1987b; Sih and Kats, 1991, 1994). Kats et al. (1988) observed that stream-dwelling small-mouthed salamander larvae responded to chemical cues from green sunfish by spending less time in the open and more time under cover. They also observed that small-mouthed salamanders that breed in ponds normally devoid of fish did not exhibit this behavior. Other studies have shown larvae that increase time spent under substrates, such as rocks and algae, become immobile or shift to more nocturnal feeding behavior in the presence of fish (Kats et al., 1988; Holomuzki, 1989a; Sih et al., 1992; Sih and Kats, 1994). Storfer and Sih (1998) noted that larvae from populations most isolated from fishless populations showed stronger anti-predator behavior. Storfer et al. (1999) observed that streamside salamander larvae from streams with fish were a more cryptic, lighter color than those found in shallow ephemeral streams without fish.
Q. Diseases. Unknown.
R. Parasites. Nematodes (Cosmoceroides dukae or C. variabilis) are known to occur in the digestive tract (Baker, 1987).
4. Conservation. Streamside salamanders usually are not found in streams where surrounding forest land has been timbered (Petranka, 1998). This suggests that deforestation and development around streams and ravines within their range will be detrimental to this species.
Only two populations are known in West Virginia, and one of these may have been destroyed recently by development. Mitchell et al. (1999) lists streamside salamanders as a species that may need to be monitored in West Virginia because of few verified populations and lack of data on the status of the known populations.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 19 Apr 2024.

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