Protogobiesox asymmetricus
| Protogobiesox asymmetricus | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Protogobiesox | ||||||||||||
| Fricke , Chen & Chen, 2017 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Protogobiesox asymmetricus | ||||||||||||
| Fricke, Chen & Chen, 2017 |
Protogobiesox asymmetricus is a small species of tortoiseshell found on the north coast of Papua New Guinea . The species and genus were described in January 2017 and stand out because of their asymmetrical body. The type specimens were caught at depths of 380 to 480 meters. As an English common name "Asymmetrical deep-water clingfish" (Asymmetrical deep-water tortoiseshell) was proposed.
features
Protogobiesox asymmetricus reaches a standard length of 5 to 6 cm. The head and body are brownish and show a faint striped pattern with reddish stripes in front and yellowish ones behind. The eyes are dark gray, the fin rays of the pectoral fins are reddish, those of the dorsal, anus and caudal fins are pink. The fin membranes are blackish. Seen from the front, the broad, flattened head is slightly asymmetrical. The spine of the males is clearly twisted to the left, that of the females to the right. The bend of the spine is 40 to 92 °. The anus and anal fin of the males are on the right side of the body, that of the females on the left, the dorsal fin of the males is on the left and that of the females is on the right. The bend begins behind the head. The intestine is also very asymmetrical. The suction disk, which is characteristic of the tortoiseshell fish and is formed from the fused ventral fins, is only rudimentary, consists of two parts and has no adhesive papillae. The fish are scaleless. On the third gill arch there are 3 gill rakes.
- Fin formula : dorsal 9–10, anal 8, pectoral 17–24, caudal 15.
Protogobiesox asymmetricus lives on sunken tree trunks and the asymmetry could be an adaptation that helps the fish to suckle on the trunks.
Systematics
Genus and species were in January 2017 the German ichthyologists Ronald Fricke and two Chinese colleagues described . The species epithet asymmetricus refers to the asymmetrical physique of the fish, the generic name Protogobiesox was assigned because the suction disk characteristic of tortoiseshell fish is only rudimentary and is therefore similar to the assumed original condition.
literature
- R. Fricke, J.-N. Chen, W.-J. Chen: New case of lateral asymmetry in fishes: A new subfamily, genus and species of deep water clingfishes from Papua New Guinea, western Pacific Ocean. In: Comptes Rendus Biologies. January 2017. doi: 10.1016 / j.crvi.2016.11.002