User:TouchetteRoman/Etheostomatinae

Wiki Outline:

Life-History :

Phylogeny & Diversity:


 * Another source to cross-reference insights on lineage divergence as well as life-history strategy differentiation, while also giving insights into breeding habitat requirements across the genus (Fluker, 2014).
 * Provides information of trait divergence across the genus, comparing different species mating behaviors and insight into how different species arose within the genus (Martin, 2016).
 * While a little more outdated, I would love to find information on hybridization across the genus Etheostomatinae, either how certain species arose through this mechanism or its prevalence in the wild, I would also like to know how hybridization affects behavioral traits along with morphological features (Keck, 2019).
 * Understanding the full phylogeny of Etheostomatinae will allow for a more holistic understanding of the genus as well as provide evolutionary knowledge on when certain traits arose within the genus and how closely related certain species are to one another. This is another source I will likely substitute for a more up-to-date version (Near, 2002).
 * To give insight into environmental factors impacting genus or species morphology and how this diversification affects behavioral and reproductive aspects of life (Hollingsworth, 2009).

Morphological Features:


 * Insight into morphological features across species in the genus Etheostomatinae, including sex-related morphological features (Martin, 2015).
 * Provides reproductive behavioral traits across the genus Etheostomatinae and any correlation between specific behavioral traits and increasing body size (Pain, 1990).
 * Elaborating on sexual and behavioral mechanisms across the genus Etheostomatinae regarding mate preferences, female mating interest, and male aggressive behavior (Héjja-Brichard, 2022).

Behavior :

Pre-copulation


 * Elaborating on sexual and behavioral mechanisms across the genus Etheostomatinae regarding mate preferences, female mating interest, and male aggressive behavior (Héjja-Brichard, 2022).
 * Provides information on behavioral displays and mating rituals across the genus Etheostomatinae (Williams, 2013).
 * Provides reproductive behavioral traits across the genus Etheostomatinae and any correlation between specific behavioral traits and increasing body size (Pain, 1990).

Mid-copulation


 * Provides information of trait divergence across the genus, comparing different species mating behaviors and insight into how different species arose within the genus (Martin 2016).
 * Insight into morphological features across species in the genus Etheostomatinae, including sex-related morphological features (Martin, 2015).
 * Provides reproductive behavioral traits across the genus Etheostomatinae and any correlation between specific behavioral traits and increasing body size (Pain, 1990).

Post-copulation


 * Provides information of trait divergence across the genus, comparing different species mating behaviors and insight into how different species arose within the genus (Martin 2016).
 * Giving insights into paternal offspring investment along with post-coital behavioral mechanisms and how they may impact the fitness of the genus (Kelly, 2012).

Sexual Selection (Predominantly about Male coloration)


 * Provides information regarding species coloration in the genus Etheostomatinae and how they may have arisen through sexual selection (Ciccotto, 2016).
 * Provides information on behavioral displays and mating rituals across the genus Etheostomatinae (Williams, 2013).
 * Provides reproductive behavioral traits across the genus Etheostomatinae and any correlation between specific behavioral traits and increasing body size (Pain, 1990).
 * Elaborating on sexual and behavioral mechanisms across the genus Etheostomatinae regarding mate preferences, female mating interest, and male aggressive behavior (Héjja-Brichard, 2022).
 * Provides information on behavioral displays and mating rituals across the genus Etheostomatinae (Williams, 2013).

Intro to Darters:;
Etheostomatinae, otherwise known as "Darter" fish, is a sub-family of fish endemic to the eastern United states, with populations reaching out as far as Missouri and the western Illinois. Darters are named for their ability to "dart" out to catch prey and avoid disturbances. They typically reside in the benthic region of riffles and pools of tributaries along a river continuum, hiding under rocks and perching upon the substrate. The majority of species within Etheostomatinae prey on aquatic invertebrates found within their respective habitats.

Phylogeny & Diversity:
Etheostomatinae is a species rich and diverse sub-family within the family Percidae of freshwater ray-finned fishes, commonly known as darters, which are endemic to eastern North America. There are multiple genera within Etheostomatinae including Ammocrypta, Crystalluria, Etheostoma, Nothonotus, and Percina, all of which have been observed as monophyletic groupings through molecular phylogenies however, two subgenera Alvordius and Hadropterus are not express as monophyletic relationships.

Speciation events can occur to a culmination of factors as both sympatric and allopatric speciation is observed across darter evolutionary history. Factors related to spatiotemporal habitat stability and life history strategies can play into speciation and genetic differentiation of darters, such as dispersal ability and gene flow in headwater reproductive habitats impacting lineage divergence. It was seen that habitat preference and isolation is a major factor contributing to speciation in darters. Speciation events are common across species of this subfamily, one example includes Barcheek darters, an ancient monophyletic grouping residing in the eastern highlands which under time-calibrated molecular phylogenetic analysis of the mitochondrial genome has presented five novel cryptic species previously thought to be associated with Etheostoma basilare.

Hybridization has been accounted for multiple times across Etheostomatinae. It is more common between species with similar egg-laying behavioral mechanisms and within the same phylogenetic clade, with sperm viability being the limiting factor of hybridization. Sperm viability has also been witnessed to decrease as temperatures increase as an extraneous factor. Other factors impacting the viability of hybridization include life history of sympatry as opposed to allopatry, habitat preference, similar spawning periods, and duration of sperm viability. Species known to bury their eggs have been viewed to reproduce under sympatric conditions while egg-guarding species typically reproduce under allopatric conditions. Hybridization is predominantly found within species of large geographic ranges, larger populations, and egg-burying reproductive mechanisms.

Morphological Features:
Darters are composed of fusiform shaped bodies that are typically less than 11 centimeters in length, and characteristically host a reduced or lack an air bladder, allowing them to reside in benthic regions of lakes, streams, and rivers. A prominent feature across many species of darters is their diverse coloration. Color preferences have been found in common darter predators such as the largemouth bass, imposing selective pressures on certain species of darters limiting nuptial coloration. Chromatic species of darters are more prominent in fast flowing habitats with coarse substrate present within the water column and low flow accumulation, more light penetration, and fewer predators present. Species with blue fins are present in habitats supporting coarse substrate along with low flow accumulation, while blue body and red fins are commonly present in rifle ecosystems, and species with red coloration on the body are present in small streams.

The size of darters can be linked to increased fitness as larger darters tend to grow faster, produce more offspring, mature earlier at a larger size, and have longer lifespans along with reproductive lifespans. Diversity of life species traits across darters have been linked to influences such as reproductive behavior, geographic range, and population size of a species.

Coloration has been viewed to be heightened through ingestion of carotenoids, which could explain how coloration is phenotypically correlated to fitness across chromatic species of Etheostomatinae.

Another prominent feature held by females across darter lineage is the presence of gential papillae, fleshy protuberances between the anus and anal fin and are associated with egg laying abilities. Phylogenetic analyses expressed that the common ancestor of Etheostomatinae buried eggs with the help of tube-like appendage with a genital pore, a pore that releases the females eggs, held at the dorsal-posterior end known as tube papillae, leading researchers to believe this is the ancestral state of darters. Tube papillae are present in majority egg laying species across Etheostomatinae, with the exception of the genus Nothonotus, which instead have a mound-tube papillae allowing females to completely bury themselves as they lay eggs under the substrate. Egg clustering species tend to express complexes of pleated rosette papillae with ventral genital pores allowing the females to attach their eggs to the underhangs of rocks and other objects.

Egg laying and Reproductive Behavior:
Selective traits may vary across species and genera, female darters have been observed to lay 500 to 1000 eggs sequentially, alluding to a promiscuous mating system with limited female mate preference and no parental care. Observations have been made that the majority of species across the diverse genus Etheostoma and that they attach eggs to their surroundings for protection. These egg attaching species mate when a female selects a location above the substrate such as a plant or rock where she will deposit her eggs, the male then mounts the female and as they vibrate the females attach eggs to her location of choosing while the male deposits sperm fertilizing the eggs. Other egg-laying behavioral characteristics include egg-guarding in which a female are courted by a male guarding a cavity, typically under flat stones, the couple then invert as the female lays eggs and the cavity ceiling as the male fertilizes them. When burying eggs, the male initiates with a courtship dance, in response the female wiggles until she is partially buried in the substrate. The male then mounts the female and similar to other species of darter, they vibrate as the females release eggs into her desired location while the male deposits sperm atop the eggs. Typically no parental care is associated with egg-burying species across the genus.

While parental care is not common within the darter subfamily, is has developed across Etheostomatinae's evolutionary history multiple times, once in the clade Goneaperca, and a more novel evolutionarily derived clade Nothonotus. Male parental care across these clades have expressed evolutionary reversals back to the lack of care for their offspring multiple times. There are at least 250 species of darters with known reproductive methodologies across the Etheostomatinae sub-family with roughly 40 species experiencing paternal care and the rest showing no parental care at all.

Sexual Selection:
Males, while predominantly giving no parental care, do invest in courtship along with egg guarding among certain species. Intra-sexual and intersexual interactions affect speciation via sexual selection, predominantly via behavioral isolation through male aggression more so than female biases, likely due to the idea that males expending more energy into courtship reproduction than females. Male darters have been found to hold female preferences and mate choice and aggression correlated to their coloration differences expressing biases regarding intra and intersexual selection. Coloration has been viewed to be correlated more with male aggression as opposed to previously suggested female selective biases expressing that the color divergence is due to intra-sexual mechanisms in certain species lacking parental care, and that male coloration and aggressiveness may have coevolved. It has been viewed across species exhibiting parental care that achromatic coloration can be a trade off between paternal care and energy allocation for reproduction. Nuptial color preference has been observed across females of the darter species E. barrenses supporting the idea that female choice can drive the evolution of male nuptial coloration; while this may not apply to all species of darters, it does help support the general idea behind coloration and how it develops under the realm of sexual selection.