Deep-sea mystery solved: astonishing larval transformations and extreme sexual dimorphism unite three fish families
Open Access
- 20 January 2009
- journal article
- Published by The Royal Society in Biology Letters
- Vol. 5 (2) , 235-239
- https://doi.org/10.1098/rsbl.2008.0722
Abstract
The oceanic bathypelagic realm (1000-4000 m) is a nutrient-poor habitat. Most fishes living there have pelagic larvae using the rich waters of the upper 200 m. Morphological and behavioural specializations necessary to occupy such contrasting environments have resulted in remarkable developmental changes and life-history strategies. We resolve a long-standing biological and taxonomic conundrum by documenting the most extreme example of ontogenetic metamorphoses and sexual dimorphism in vertebrates. Based on morphology and mitogenomic sequence data, we show that fishes currently assigned to three families with greatly differing morphologies, Mirapinnidae (tapetails), Megalomycteridae (bignose fishes) and Cetomimidae (whalefishes), are larvae, males and females, respectively, of a single family Cetomimidae. Morphological transformations involve dramatic changes in the skeleton, most spectacularly in the head, and are correlated with distinctly different feeding mechanisms. Larvae have small, upturned mouths and gorge on copepods. Females have huge gapes with long, horizontal jaws and specialized gill arches allowing them to capture larger prey. Males cease feeding, lose their stomach and oesophagus, and apparently convert the energy from the bolus of copepods found in all transforming males to a massive liver that supports them throughout adult life.Keywords
This publication has 8 references indexed in Scilit:
- RAxML-VI-HPC: maximum likelihood-based phylogenetic analyses with thousands of taxa and mixed modelsBioinformatics, 2006
- Major patterns of higher teleostean phylogenies: a new perspective based on 100 complete mitochondrial DNA sequencesMolecular Phylogenetics and Evolution, 2003
- Organization of the Mitochondrial Genome of a Deep-Sea Fish, Gonostoma gracile (Teleostei: Stomiiformes): First Example of Transfer RNA Gene Rearrangements in Bony FishesMarine Biotechnology, 1999
- Synopsis of the whalefishes (family Cetomimidae) with descriptions of four new generaRecords of the Australian Museum, 1989
- Enzyme Clearing of Alcian Blue Stained Whole Small Vertebrates for Demonstration of CartilageStain Technology, 1977
- Fishes of the Western North Atlantic. Part Six. Order Heteromi (Notacanthiformes), Suborder Cyprinodontoidei, Order Berycomorphi (Beryciformes), Order Xenoberyces Stephanoberyciformes), Order Anacanthini (Gadiformes) in Part MacrouridaeIchthyology & Herpetology, 1974
- Functional Morphology and Classification of Teleostean FishesPublished by Walter de Gruyter GmbH ,1971
- Scientific results of explorations by the U. S. Fish Commission steamer Albatross.No. XXVIII.—On Cetomimidae and Rondeletiidae, two new families of bathybial fishes from the north western AtlanticProceedings of the United States National Museum, 1895