The streamside salamander (Ambystoma barbouri) is a species of mole salamander from North America, occurring in several Midwestern states of the US.[2]
| Streamside salamander | |
|---|---|
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Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Amphibia |
| Order: | Urodela |
| Family: | Ambystomatidae |
| Genus: | Ambystoma |
| Species: | A. barbouri
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| Binomial name | |
| Ambystoma barbouri Kraus & Petranka, 1989
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Description
editThe streamside salamander is a medium-sized amystomatid salamander. It typically has a relatively small head and a short rounded snout. The salamander's body is relatively short and flaccid. There are 14-15 distinct costal grooves when fully grown. The tail is fairly short and thick, and it contains costal grooves that correspond directly to the vertebrae. Coloring is typically a dark black background covered in lichen-like markings in gray and brown. The species has more teeth, with a unique cusp shape, in its maxillary and premaxillary positions than its close relatives teeth, and is somewhat stockier.[3]
Distribution and habitat
editThe species is found in central Kentucky, southwestern Ohio, southeastern Indiana. There is an isolated population in Livingston County, Kentucky. Overall distribution is uncertain due to the species' cryptic habits and possible confusion or hybridization with the small-mouth salamander.[3] Adults can be found underground and under rocks or leaves in deciduous forests at moderate elevations.[1]
The streamside salamander is closely related to the pond-breeding small-mouth salamander, from which it is believed to have diverged during the late Pleistocene era as a result of climatic warming. Disappearance of pond habitats are thought to have forced the species to adapt to the new stream habitat.[3][4]
Ecology
editPredator avoidance
editThe female places eggs on the underside of submerged rocks in stream pools to reduce risk of predation on eggs by fish. The salamander also uses olfactory cues to detect the presence of fish and tends to avoid placing eggs in pools that have high fish densities.[5] Adults are not normally at risk of fish predation, but both eggs and young larvae may be targeted. It has been shown that the hatching time of streamside salamander eggs was responsive to the presence of green sunfish in the habitat, leading to the emergence of larvae that are larger and less easily preyed on, or possibly less susceptible to involuntary drift into areas with high fish densities.[6]
Larvae show a range of coloration types that are believed to be driven by several different mechanisms. In fish-rich habitats, larvae tend to have light pigmentation that assists in blending in with the stream substrate and reduces the likelihood of being detected by predators. In the absence of predators, darker pigmentation that may assist in maintaining a higher body temperature and thus greater activity and foraging levels is more common.[7] Risk of UV light damage may also drive a preference for darker coloration. Larvae may be able to play off these differing pigmentation drivers against each other by preferentially seeking out darker sediment that allows high camouflage while maintaining dark pigmentation.[8]
Evolutionary genetics
editGene flow
editThe streamside salamander has been a subject of interest in understanding the interaction between gene flow and natural selection. Salamander larvae that live in the presence of green sunfish are more likely to survive if they have stronger antipredator behavior, including reduced activity; however, larvae that are born in fish-free, ephemeral pools have higher survival with increased activity and higher feeding rates, traits which allow them to metamorphose before their aquatic habitat dries. Salamanders from highly isolated populations occupying habitat harboring fish have stronger antipredator behavior than salamanders from populations that are less isolated and more likely to experience gene flow from populations occupying fish-free habitats; this suggests that gene flow may hinder local adaptation of salamander populations to fish presence.[9]
Local adaptation
editPopulations of the streamside salamander show evidence of adaptation to local environmental conditions, including the presence or absence of fish,[9] as well as abiotic environmental factors.[10] A landscape genomics study identified a small subset of genome-wide single nucleotide polymorphisms (SNPs) at which allele frequencies show significant correlations with mean annual temperature, temperature seasonality, and annual precipitation;[10] genes near the aforementioned SNPs function in hypoxia response and development, suggesting that geographic variation in oxygen availability (which correlates with water temperature and elevation) may impose divergent selection among salamander populations.[10]
Conservation
editTotal streamside salamander population is estimated at above 10,000 individuals, but precise data are lacking. The species is under pressure from habitat destruction (conversion of forests to pasture and residential areas) and water pollution.[1] Triphenyltin, a common pesticide used in pecan, potatoes, beets, celery, coffee, and rice agriculture was found to cause streamside salamander larva mortality of 90% if present at concentrations above 5 μg/L. However, even lower levels led to reduced feeding and growth rates.[11]
References
edit- ^ a b c Geoffrey Hammerson (2004). "Ambystoma barbouri". IUCN Red List of Threatened Species. 2004: e.T59053A11875949. doi:10.2305/IUCN.UK.2004.RLTS.T59053A11875949.en. Retrieved 19 November 2021.
- ^ Frost, Darrel R. (2022). "Ambystoma barbouri Kraus and Petranka, 1989". Amphibian Species of the World: An Online Reference. Version 6.1. American Museum of Natural History. doi:10.5531/db.vz.0001. Retrieved 22 November 2022.
- ^ a b c Kraus, F. (1996). "Ambystoma barbouri Kraus and Petranka Streamside Salamander" (PDF). Catalogue of American Amphibians and Reptiles. 621: 1–4.
- ^ Eastman, Jonathan M.; Niedzwiecki, John H.; Nadler, B. Paul; Storfer, Andrew (2009). "Duration and consistency of historical selection are correlated with adaptive trait evolution in the streamside salamander, Ambystoma barbouri". Evolution. 63 (10): 2636–2647. doi:10.1111/j.1558-5646.2009.00741.x. PMID 19500149. S2CID 6979779.
- ^ Kats, Lee B.; Sih, Andrew (1992). "Oviposition Site Selection and Avoidance of Fish by Streamside Salamanders (Ambystoma barbouri)". Copeia. 1992 (2): 468–473. doi:10.2307/1446206. JSTOR 1446206.
- ^ Moore, Robert D.; Newton, Blake; Sih, Andrew (1996). "Delayed Hatching as a Response of Streamside Salamander Eggs to Chemical Cues from Predatory Sunfish". Oikos. 77 (2): 331–335. Bibcode:1996Oikos..77..331M. doi:10.2307/3546073. JSTOR 3546073.
- ^ Storfer, Andrew; Cross, Jonra; Rush, Victor; Caruso, Joseph (1999). "Adaptive coloration and gene flow as a constraint to local adaptation in the streamside salamander, Ambystoma barbouri". Evolution. 53 (3): 889–898. doi:10.1111/j.1558-5646.1999.tb05383.x. PMID 28565629. S2CID 31230785.
- ^ Garcia, Tiffany Sacra; Sih, Andrew (2003-09-01). "Color change and color-dependent behavior in response to predation risk in the salamander sister species Ambystoma barbouri and Ambystoma texanum". Oecologia. 137 (1): 131–139. Bibcode:2003Oecol.137..131G. doi:10.1007/s00442-003-1314-4. PMID 12838403. S2CID 10217028.
- ^ a b Storfer, A.; Sih, A. (1998). "Gene flow and ineffective antipredator behavior in a stream-breeding salamander". Evolution. 52 (2): 558–565. doi:10.1111/j.1558-5646.1998.tb01654.x. PMID 28568324.
- ^ a b c Beer, Marc A.; Kane, Rachael A.; Micheletti, Steven J.; Kozakiewicz, Christopher P.; Storfer, Andrew (February 2022). "Landscape genomics of the streamside salamander: Implications for species management in the face of environmental change". Evolutionary Applications. 15 (2): 220–236. Bibcode:2022EvApp..15..220B. doi:10.1111/eva.13321. ISSN 1752-4571. PMC 8867708. PMID 35233244.
- ^ Rehage, Jennifer Schöpf; Lynn, Scott G.; Hammond, John I.; Palmer, Brent D.; Sih, Andrew (2002). "Effects of larval exposure to triphenyltin on the survival, growth, and behavior of larval and juvenile Ambystoma barbouri salamanders". Environmental Toxicology and Chemistry. 21 (4): 807–815. doi:10.1002/etc.5620210417. PMID 11951955. S2CID 14382240.