| Puerto Hondo Stream Salamander | |
|---|---|
| Conservation status | |
| Scientific classification | |
| Kingdom: | Animalia |
| Division: | Chordata |
| Class: | Lissamphibia |
| Order: | Caudata |
| Family: | Ambystomatidae |
| Genus: | Ambystoma |
| Species: | A. ordinarium |
| Binomial name | |
| Ambystoma ordinarium (Taylor, 1840) |
|
The Puerto Hondo Stream Salamander, Ambystoma ordinarium, is a Mole salamander from the Cordillera Volcánica within the Mexican state of Michoacán.
Contents |
A. ordinarium are only found at Puerto Hondo, in a small stream four miles west of El Mirador, and at Puerto Garnica, in another small stream nearby with dark, cold waters and a temperature of 12.4 C. These streams are high in the mountains, and lay at elevations of 9000 and 9400 feet respectively. Larvae and Neotenes have been found swimming against the current of the streams, at depths of 5–12 inches. Terrestrial adults remain near stream banks, and are often found side-by-side with gilled adults, but can also be found under debris in pine and fir forests up to 30 meters away from streams. [2]
A. ordinarium larvae and neonates have sparse, evenly distributed melanophores and rows of light silver-yellow specks. Larvae have well-developed fins, small but bushy gills, and 16–24 gill rakers (average, 18.8) on their third gill arch. Larvae reach a maximum size of 100 mm SVL and 191 mm total length. [3][4]
At sexual maturity, these salamanders measure between 70 and 75 mm SVL. Terrestrial adults reach a maximum size of 86 mm SVL. They have narrow heads, and 16–24 tooth-rakers on the 3rd arch. Adults generally have uniform dark or black coloring on their backs, but some may be mottled and others may retain larval coloration. [4][5]
A. ordinarium live about two years [6]
The salamander has a prolonged breeding season and may breed throughout the year [4]. Average of 109 egg are laid alone or in 2–5 egg clusters on the underside of root, branches and rock, hanging free in the current. Eggs are pigmented, measure 9.9 mm, and encased in three capsules including a thick outer capsule. [4]
New hatchling have fully developed fins, and both larvae and adult walk on the bottom more than they swim [4].
They are diurnal, hiding under cover of stream bank or under log early in the day and come out by late morning [4]
Terrestrial prey include grasshoppers, ants, leafhoppers, scuds, earthworms, and nematodes. Aquatic prey include aquatic insect larvae such as caddisfly larvae, small aquatic beetles, and clams [2][7]
A. ordinarium are able to live in cleared pastures and watering holes, so the decline of forests does not pose an immediate threat. Fragmentation of their habit due to human development and the desiccation of streams is the biggest threat to the species, which is protected in Mexico. [2][8]
It has been suggested that this is the same species as the Lake Patzcuaro Salamander, Ambystoma dumerilii, based on genetic analysis, but their habitats have been isolated for 7–10 million years [9] Ambystoma dumerilii is also wholly neotenic, while Ambystoma ordinarium is variable but mostly terrestrial.