Radiicephalus
| Radiicephalus | ||||||||||||
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Radiicephalus elongatus |
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| Systematics | ||||||||||||
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| Scientific name of the family | ||||||||||||
| Radiicephalidae | ||||||||||||
| Osório , 1917 | ||||||||||||
| Scientific name of the genus | ||||||||||||
| Radiicephalus | ||||||||||||
| Osório, 1917 |
Radiicephalus is a genus of fish from the order of the shiny fish-like (Lampriformes). The genus wasscientifically describedin 1917 together with the then only known species, Radiicephalus elongatus . R. elongatus occurs in the eastern Atlantic from the Azores to South Africa. Another species was described in 2018. The holotype of Radiicephalus kessinger was caught in the western Pacific, southwest of Taiwan . In addition, fish larvae are known from the western Atlantic and the eastern Pacific,but they are not assigned tothe genus Radiicephalus but any specific species.
features
The two types of radiicephalus described so far have an elongated, ribbon-like body that is strongly flattened at the sides. The maximum body height is 11.7 to 13.1% of the standard length , the width of the body is only 2.3 to 2.9% of the standard length. The body gradually tapers backwards and becomes flat and rod-shaped at the back of the body. The eyes are large and almost a third of the length of the head in diameter. The number of vertebrae is between 114 and 125 (37 to 39 trunk vertebrae and 76 to 88 tail vertebrae). The dorsal fin is very long and is supported by 156 to 161 fin rays, the first four to five of which are elongated. The anal fin is short with six to seven rays. The pectoral fins have ten to eleven rays, the ventral fins five to ten. The narrow caudal fin divides into a small upper lobe, which is supported by four to five fin rays and a very elongated lower lobe, which is supported by seven to nine fin rays. The body of the Radiicephalus species is coated with a guanine-containing epidermis , which is interspersed with numerous elliptical pores that extend from mushroom-shaped papillae. The surface of the guanine layer is silvery and shows a pronounced parallelogram pattern. Under the epidermis, the body is covered with small, thin scales. The sideline is covered by tubular scales and extends to the lower caudal fin lobe.
species
- Radiicephalus elongatus Osório, 1917
- Radiicephalus kessinger Koed & Ho, 2018
Individual evidence
- ↑ a b c Koeda, K. & Ho, H.-C. (2018): A new tapertail species (family Radiicephalidae; Lampridiformes) from Taiwan, the first confirmed western Pacific Ocean record of the family. Ichthyological Research, October 2018.
- ↑ Radiicephalus elongatus on Fishbase.org (English)