Leftvents seadevils comprise the family Linophrynidae, Marine life Actinopterygii within the suborder Ceratioidei, the deep sea anglerfishes. These fishes are found in the Atlantic, Indian and Pacific Oceans.
The fishes in the Linophrynidae have varied morphologies but there are some other general characteristics. In metamorphosed females have short, rather globose bodies with large heads and a very large mouth. The jaws are almost equal in length, although some species have a , with a spine on the symphysis of the lower jaw. There are also well-developed spines on the bone, while the Articular bone and quadrate bone have no spines. The Hyomandibula has a single head, this being a feature shared with the families Neoceratiidae and Gigantactinidae. The operculum is forked with a concave rear margin, the sub opercle is long and slender and has no spines on its forward margin while the preopercle has at least one well developed spine. They have smooth, naked skin with no spinules in the skin and the teeth are very varied between genera.
The illicium has a very short pterygiophore, its front end is hidden within the skin of the head or protrudes just a little above the skin on the snout. There is no relict second cephalic spine. The illicium has a length which is variable between genera, from being almost completely encased in the skin to up to 70% of the standard length. The esca has a morphology which is also highly variable between the genera. Linophryne has a hyoid barbel that is Bioluminescence. Metamorphosed females are typically dark brown to black, although the appendages of the esca, the parts of the bulb of the esca close to the tip and the hyoid barbel of Linophryne, and the fin rays have no pigmentation. Haplophryne is an exception in that it lacks pigmentation.
The metamorphosed males have very large, forward pointing, rather tubular eyes with diameters that are equivalent to between 6% and 9% of the standard length. The olfactory organs are also very large and the number of olfactory lamellae varies by genera. Some genera also have teeth in the jaws of males, others do not. They usually do not have spines on the sphenotic bone and no males have a hyoid barbel and the skin is naked with no spinules, in free living males pigment may or may not be present. The parasitic males have denticular teeth, while their eyes, and olfactory organs degenerate and they have very inflated bellies.
The largest published standard length of a metamorphosed female is , that of a free-living male is and that of parasitic males is .
At least two fossils of Acentrophryne longidens have been found in Late Miocene-aged limestone from Rosedale, California.Carnevale & Pietsch "The Deep-sea Anglerfish Genus Acentrophryne (Teleostei, Ceratioidei, Linophrynidae) in the Miocene of California" Journal of Vertebrate Paleontology 29(2):372–378, June 2009 [1]
When he latches onto a female the male releases enzymes to dissolve the female's tissue in the vicinity of his mouth, resulting in the male and female becoming united anatomically. After the union, the male's eyes, fins, and internal organs are lost, although the testes are retained. Its circulatory system becomes fused with the female's, and from the point of union the male receives all its nutrients through the joined blood circulation. The male stays attached to the female for the rest of her life and fertilises her spawn many times. Some species may have more than one male sexual parasite. This strategy evolved to ensure that the spawn is fertilised in the sparsely populated habitat of these deepwater anglerfish.
In other vertebrates the host's immune system would reject such a sexual parasite but in the leftvents, and other sexually parasitic anglerfish, many of the genes involved in the rejection of pathogens and foreign tissue are missing.
Genera
Fossil record
Biology
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