Grammonus thielei
| Grammonus thielei | ||||||||||||
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Grammonus thielei , photo: Werner Thiele |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Grammonus thielei | ||||||||||||
| Nielsen & Cohen, 2004 |
Grammonus thielei is a species of gut fish-like that occurs endemically inlimestone caves filledwith sea or brackish water at the northern end of the Indonesian island of Tomia, southeast of Sulawesi. It was named after its discoverer Werner Thiele. The sluggish fish usually remain motionless under rocky outcroppings with only slight fins movements.
features
Male Grammonus thielei grow to be 18 centimeters long, females remain slightly smaller at 15 centimeters. The head occupies 33% of the standard length (SL), has a width of 20% of the SL and a height of 29% of the SL. The number of vertebrae is 38 (11 trunk vertebrae, 26 tail vertebrae ( uroneuralia counted as 1)). On the first gill arch there are 18 to 19 gill rakes , three to four are clearly developed, 14 to 16 only briefly. The elongated fish have 66 rays in the dorsal fin , 41 in the anal fin , 21 in the pectoral fins , one in the ventral fins and 12 in the tiny caudal fin. The caudal fin has not grown together with the dorsal and anal fin. There is a large lateral pore at the gill cover corner . There are about 70 scales along the sidelines. The fish are marbled brownish, the eyes are dark blue.
Way of life
Grammonus thielei lives in limestone caves and karst funnels on the shores of the Indonesian island of Tomia, which are probably connected to each other at depths of two to 30 meters. They mainly stay in lightless areas with no current, but have also been observed under rock ledges in cave entrances. The fish do not react to the light of flashlights, the escape distance is only 2 centimeters. Since the fish are still colored and have well-developed eyes, it is believed that the transition to a cave-dwelling way of life was not too long ago.
literature
- Nielsen, JG and DM Cohen, 2004. Grammonus thielei (Ophidiiformes: Bythitidae) - a new bythitid cavefish from off Sulawesi, Indonesia. The Beagle 20: 83-86.
Web links
- Grammonus thielei on Fishbase.org (English)