| Mink frog | |
|---|---|
 | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Amphibia |
| Order: | Anura |
| Family: | Ranidae |
| Genus: | Lithobates |
| Species: | L. septentrionalis |
| Binomial name | |
| Lithobates septentrionalis (Baird, 1854) | |
 | |
| Range ofL. septentrionalis | |
| Synonyms | |
Rana septentrionalis | |
Themink frog (Lithobates septentrionalis) is a smallspecies offrog native to theUnited States andCanada. They are so named for their scent, which reportedly smells like amink. The scent is more akin to that of rottingonions to those unfamiliar with mink. It is also sometimes referred to as thenorth frog.
The mink frog is a small frog, growing up to 4.8 to 7.6 cm (1.9 to 3.0 in). The dorsum is generallygreen in color, with darker green andbrown blotching and the belly is a cream,yellow, orwhite. They aresexually dimorphic in that males typically have a bright yellow colored throat, while females have a white colored throat, and thetympanum of the male is larger than theeye, while the female's is smaller than or the same size as the eye. The frogs have a pale-colored underside and bright green lips.
The mink frog is predominantly aquatic, living among the vegetation (especially amonglily pads) in ponds, swamps, and streams around wooded areas. They feed on a wide variety of things, includingspiders,snails,beetles, and otherinvertebrates. As tadpoles they consume primarilyalgae and decaying plant matter.
Mating generally takes place in late spring and early summer. These frogs prefer cold, well-oxygenated wetland breeding sites where during the late night hours, but occasionally during the day, males call to attract females while floating on the water's surface or partially resting on floating vegetation.[3] Between 500 and 4000eggs can be laid by the female at any one time, generally in deep water. Egg masses are usually found close to floating vegetation and hatch within days of being deposited.[3] Tadpoles remain in the larval stage for approximately one year beforemetamorphosing into froglets. Maturity is reached in a year for males, and two years for females.
Mink frogs are found in the United States in the states ofMinnesota,New Hampshire,Wisconsin,Michigan,Maine,Vermont, andNew York. They are also found inCanada in the provinces ofNova Scotia,New Brunswick,Newfoundland and Labrador,Quebec,Ontario, andManitoba. This largely aquatic frog's southern range limit is at the highest latitude of any North American frog and there is evidence that more southern populations of this frog became extinct within the past century.[3]
In recent years, it seems that the general populations of mink frogs are in decline.[4] In a 1999 study conducted by David Gardiner and David Hoppe it was noted that there was an increase in mink frog deformities. "The spectrum of deformities includes missing limbs, truncated limbs, extra limbs (including extra pelvic girdles), and skin webbings. We also describe a newly recognized malformation of the proximal-distal limb axis, a bony triangle. In this abnormality, the proximal and distal ends of the bone are adjacent to one another forming the base of a triangle. The shaft of the bone is bent double and protrudes laterally, the midpoint of the bone forming the apex of the triangle."[5] The study comes to the conclusion that these deformities are a result of exposure to exogenous retinoids, but more study is needed to make a sure determination.
Media related toLithobates septentrionalis at Wikimedia Commons
Data related toMink frog at Wikispecies
