Blotched Salamander, Spotted Salamander, Buchi Sansho-uo
© 2005 Henk Wallays (1 of 6)
H. kimurae can usually be distinguished by the yellowish or golden color and uniform size of its blotches and H. stejnegeri by its larger size and generally large amber-colored blotches on both flanks and back (Goris 2004).
Distribution and Habitat
Life History, Abundance, Activity, and Special Behaviors
A pair of elongate and spiral egg sacs, each containing a total of 17-36 eggs, is laid at a time. The gelatinous envelope of the sacs is transparent and tough but less so than that of H. kimurae egg sacs (Goris 2004).
The egg is white in color, with much yolk, and has a diameter of about 5 mm (Junji Oyama 1929). Gastrulation is completed a week after spawning. Soon after this, neural folds are formed. About ten days are required for the completion of the neural grove. After two weeks the fusion of the neural folds takes place and the head part is distinguishable. The head becomes more well-defined two or three days after this. The rudiments of the external gills arise behind the eyeballs and the tail appears on the hinder part of the body. At this time the embryo is 8 mm in length, a little bent, and holds a round yolk mass on the ventral region. Three weeks after spawning, the embryo becomes straight and 15 mm in total length, the head being about 2 mm, the tail about 5 mm. The external gills consist of three pairs of rods and are 1 mm in length. The fore-limbs now project and the nostrils appear. Black pigment appears in the eyes. The fin arises on the tail. The yolk mass becomes elongated, lying along the body. Two or three days later the external gills increase in length and little branches spring up from them. The rudiments of the hind-limbs become visible. Pigment gradually appears over the surface of the body. By the end of the fourth week the total length reaches 19 mm, external gills measure 5 mm, and two or three toes appear on the fore-limbs. The embryo hatches out in the fifth week. At this time the total length is 21-22 mm, the fore-limbs measure 2 mm, and the hind-limbs 1 mm. A good quantity of yolk remains in the abdomen. Newly hatched larvae have no balancers and generally lie on their side on the bottom of the water, remaining in this position until the fore-limbs are strong enough to perform their function (Junji Oyama 1929).
The larvae live along the edges of the stream where the current is weak and feed on aquatic insects and other prey like H. kimurae. The larvae of some populations have claws, which disappear at metamorphosis. Some larvae metamorphose and leave the water from the middle of August to the end of September, while others remain in the water until the following spring or summer (Goris 2004).
Goris, R.C. and Maeda, N. (2004). Guide to the Amphibians and Reptiles of Japan. Krieger Publishing Company, Malabar, Florida.
Oyama, J. (1929). ''Some embryological notes of Hynobius naevius.'' Copeia, 1929, 92-94.
Written by Nichole Winters (NicholeWinters AT gmail.com), URAP
First submitted 2006-10-05
Edited by Tate Tunstall (2008-02-03)
Species Account Citation: AmphibiaWeb 2008 Hynobius naevius: Blotched Salamander <http://amphibiaweb.org/species/3889> University of California, Berkeley, CA, USA. Accessed Oct 21, 2020.
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Citation: AmphibiaWeb. 2020. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 21 Oct 2020.
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