Male Parasitism in Angler Fish
Biology 342 Fall 2006
Mikey Badr and Will Gester
The term anglerfish can refer to any member of the order lophiiform. However the suborder ceratiodei is defined by extreme sexual dimorphism and a luminescent lure. The ceratioidei are much more derived than their bottom-feeding cousins, which include the monkfish. The suborder contains 160 currently recognized species. The evolutionary history of the ceratioides is elusive, mainly due to a scant fossil record, though some have been found. A 2008 study by Carnevale et al. of fossils unearthed in Los Angeles during the construction of a metro line analyzed 9 specimens. This study was able to assign each to extant genus of ceratioidei, suggesting that the very little morphological change has occurred in the taxa since the Late Miocene. These results represent the only confirmed fossil record of the ceratiod anglerfish.
Phylogenetic treed of the suborder lophiiform (Source: http://tolweb.org/Lophiiformes/21989) and ceratoidei (Source: http://tolweb.org/Ceratioidei/22000)
A recent analysis of mitogenomic DNA from various ceratiods support the hypothesis that obligate sexual parasitism is monophyletic within lophiiforms. Additionally, this research suggests that temporary attachment was an evolutionary precursor to permenant attachment. Interestingly, the most parsimonious phylogenetic tree suggests that while temporary attachment is an acestral trait, obligate or facultative parasitism has evolved three seperate times within the osuborder of ceratoidei, meaning that this trait is paraphyletic. (Miya 2010)
A parsimonious phylogenetic tree made using mtDNA, focusing on the evolutionary history of male sexual parasitism. ML refers to Maximum Likelyhood, the model by which the tree was constructed. (Miya 2010)