Lepomis is a genus of freshwater fish in the sunfish family, Centrarchidae, in the orderPerciformes. Perhaps the most recognizable species of this genus is the bluegill. Some Lepomis species can grow to a maximum overall length of, though most average around. They are widely distributed throughout the lakes and rivers of the United States and Canada, and several species have been transplanted and flourished around the world, even becoming pests. Trade in some Lepomis species is prohibited in Germany for this reason. Many are sought by anglers as panfish, and large numbers are bred to stock lakes, rivers, and tributaries. Lepomis species are sometimes referred to as bream, but the term more properly refers to the unrelated European cypriniformfish of genus Abramis. The generic nameLepomis derives from the Greek λεπίς and πῶμα.
Phylogeny
Phylogeny of all Lepomis species based on a partitioned mixed-model Bayesian analysis of a seven gene dataset of mitochondrial and nuclear gene DNA sequences by Near et al., expanded with fossil species. Subgenera in bold follow Bailey : *)L. peltastes was not originally included in the analysis by Near et al. and is included here based on commonly accepted sister relationship to L. megalotis. **) See section 'Evolutionary History' below for explanation. ***) Phylogenetic position in clade II uncertain. See section 'Fossil record' for clarification.
Evolutionary history
Phylogenetic reconstructions using a combination of nuclear and mitochondrial DNA sequences calibrated with fossils to estimate ages of divergences suggests that the genus Lepomis diverged from the black bass in genus Micropterus, its sister taxon, about 25 million years ago. The deepest split among currently living species of Lepomis is dated to ~15 million years ago and separates genus Lepomis into two clades: clade I that leads to the modern bluegill, orange-spotted, green, and warmouth sunfish, and a clade II that includes the modern long-ear, red-breasted, pumpkinseed, redear, and red-spotted sunfish. The timing of this speciation event roughly corresponds with the Middle Miocene disruption that resulted in increased aridity on the plains of North America and a transition from savannah to grasslands, although the relevance of these environmental changes to the evolution of Lepomis is unclear.
Fossil record
No fossils unambiguously assigned to genus Lepomis are currently known from the putative stem-lineage that must have existed between 25-15 million years ago, spanning most of the early Miocene. Currently, four extinct species of Lepomis are known from the fossil record: There are at least two as yet undescribed fossil species of Lepomis that reach back to the middle Miocene:
Lepomissp. A consists of fragmentary fossils of its lower jaw from Nebraska, dated to 13.5 million years ago, and shows morphological similarities to the modern Lepomis microlophus, although its great age means that this species predates the divergence of any of the living species.
Lepomissp. B was found in deposits in Kansas, dated to 12 million years ago.
Two other more recent fossil species appear to be closely allied to Lepomis gulosus, and indeed their earliest occurrence may be close to the divergence of the lineage leading to the modern warmouth from other species of Lepomis:
Lepomis kansasensis lived 6.6 million years ago, and had pterygoid teeth, indicating a close relationship to the warmouth.
Lepomis serratus is known from 3.4 to 2.0 million year old deposits in Nebraska, and also appears to be closely related to or ancestral to the warmouth on the basis of its preopercle.
Species
There are currently 13 recognized species in this genus:
