Photocorynus spiniceps
| Photocorynus spiniceps | ||||||||||||
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Photocorynus spiniceps |
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| Scientific name of the genus | ||||||||||||
| Photocorynus | ||||||||||||
| Regan , 1925 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Photocorynus spiniceps | ||||||||||||
| Regan , 1925 |
Photocorynus spiniceps is a deep-sea frogfish from the family of devil anglers (Linophrynidae). It is the only species within the monotypic genus Photocorynus .
description
There is a pronounced sexual dimorphism , because while the females are 5 to 6.9 centimeters long, the dwarf males only reach a length of a few millimeters to just under one centimeter.
female
The females have a stocky, rounded body with a very large, broad head. The skull bones have thorn-like extensions in this species. Fangs, which are smaller in Photocorynus spiniceps but more numerous than in most of the other genus of the Teufelsangler family, and a dummy bait known as a "fishing rod" or "lantern" are used to acquire prey. This is formed by the first dorsal fin ray, which is placed on the head, and is provided with a light organ . With the help of the bioluminescence generated by symbiotic bacteria , prey animals are attracted in the darkness of the deep sea. The first dorsal fin ray is relatively short in Photocorynus spiniceps .
male
The sexually mature males reach a length of only 6.2–7.3 millimeters. Free-living males with a body length of 9.3 millimeters were also found. Most males, however, are smaller than any other vertebrate animal . They have oversized eyes and olfactory organs in the area of the nose, with which they can perceive chemical substances. After the larval stage , they look for females with the help of these sensory organs. As soon as they have found one, they attach themselves to a suitable place with their mouth, which also has corresponding tooth formations when reaching sexual maturity. The tissue of the partner eventually grows together, the blood circulation merges. The male is nourished by the female through the bloodstream. It now lives like a parasite , in this case one speaks of sexual parasitism. The male uses his gonads , which occupy almost the entire body, to produce sperm, which ensure the fertilization of the eggs released into the water by the female.
distribution
The species is mainly found in the tropical and subtropical waters of the western Atlantic , but is also found in these geographical latitudes in the western and eastern Pacific . It lives in the mesopelagial and in the underlying bathypelagial , the deep sea zone below 1000 meters water depth, where no more light reaches.
Way of life
Like the other frogfish, Photocorynus spiniceps attracts prey with the help of bioluminescence. The sexually mature females lurk motionless on the ocean floor until potential prey is attracted by the glowing dummy bait. The prey, mostly other deep-sea fish, can be sucked in through the movable jaws. The expandable stomach also allows the females to swallow prey that is almost as big as itself.
Research history
The specimen that Charles Tate Regan used for the first description was caught during an expedition by the Danish marine biologist Johannes Schmidt with the research vessel Dana in the Gulf of Panama at a depth of 1250 meters between 1920 and 1922 . Although the captured female was not yet sexually mature with a length of 62 millimeters, a male almost one centimeter in length had already attached itself to the head.
Individual evidence
- ↑ Charles Tate Regan: Dwarfed Males Parasitic on the Females in Oceanic Angler Fishes (Pediculati Ceratioidea). Proceedings of the Royal Society of London, Series B, 97, 684, pp. 386-400, 1925 doi : 10.1098 / rspb.1925.0006
- ↑ a b Theodore W. Pietsch: Linophrynidae. Sinistral Seadevils. Version 02, October 2007, The Tree of Life Web Project
- ^ Theodore W. Pietsch: Dimorphism, parasitism, and sex revisited: modes of reproduction among deep-sea ceratioid anglerfishes (Teleostei: Lophiiformes). Ichthyological Research, 52, 3, pp. 207-236, 2005 doi : 10.1007 / s10228-005-0286-2
- ^ SH Weitzman & RP Vari: Miniaturization in South American freshwater fishes; an overview and discussion. Proceedings of the Biological Society of Washington, 101, pp. 444-465, 1988
- ↑ Masaki Miya, Theodore W. Pietsch, James W. Orr, Rachel J. Arnold, Takashi P. Satoh, Andrew M. Shedlock, Hsuan-Ching Ho, Mitsuomi Shimazaki, Mamoru Yabe & Mutsumi Nishida: Evolutionary history of anglerfishes (Teleostei: Lophiiformes): a mitogenomic perspective. BMC Evolutionary Biology, 10, 1, 58, February 2010 doi : 10.1186 / 1471-2148-10-58
literature
- Theodore W. Pietsch: Dimorphism, parasitism, and sex revisited: modes of reproduction among deep-sea ceratioid anglerfishes (Teleostei: Lophiiformes). Ichthyological Research, 52, 3, pp. 207-236, 2005 doi : 10.1007 / s10228-005-0286-2
Web links
- Photocorynus spiniceps on Fishbase.org (English)
- Theodore W. Pietsch: Linophrynidae. Sinistral Seadevils. Version 02, October 2007, The Tree of Life Web Project