Gulf flounder

The Gulf flounder (''Paralichthys albigutta'') is a species of saltwater flounder.

Description

The Gulf flounder is a flatfish that swims on its side. Their two eyes look upward when swimming. They have sharp teeth, two eyes on one side, and have a white side. Paralichthys albigutta is widely distributed in the western North Atlantic. Adults are found in a variety of habitats, but generally prefer hard, sandy bottoms; juveniles settle in high salinity seagrass beds. Longevity is 7–10 years and females reach maturity between 1–2 years. It is commercially and recreationally exploited. The center of abundance of ''Paralichthys albigutta'' in the Gulf of Mexico is along the northeastern coast of Florida. West of the Mississippi River delta, it occurs in very low numbers. It appears to naturally occur in low abundance in seagrass beds. It is common in museum collections (660 lots). Many species of fishes, including ''P. albigutta'', have experienced declines in abundance in the Northern Gulf of Mexico from 1970-2000; although Fodrie'' et al.'' (2010),(This needs to be challenged, as in coastal Western Louisiana, the flounder have not been as plentiful in 50 years, as of 2018), attributed this at least in part to the effects of global rises in sea temperature, there are also a number of other factors (e.g., bycatch in trawl fisheries, increased recreational landings: T. Munroe pers. comm. 2015) that may contribute to these declines. Gill netting has been implicated in the decline of flounder stocks in North Carolina due to targeting of non-reproductive juveniles; however, the population-level effects of this method of harvest on ''P. albigutta ''are unknown

Habitat

This demersal species'' ''occurs in shallow depths within estuaries and coastal environments; it is most commonly found on the continental shelf at depths of 18–92 m, but has been collected to about 130 m. It is found in a variety of habitats, including seagrass beds,Gloeckner, D.R., Luczkovich, J.J. 2009. Experimental assessment of trophic impacts from a network model of a seagrass ecosystem: Direct and indirect effects of Gulf Flounder, Spot and Pinfish on benthic polychaetes. ''Journal of Experimental Marine Biology and Ecology'' 357: 109–120.
coastal lagoons, flat hard-bottom and limestone ledges. It prefers hard, sandy bottoms. Juveniles utilize vegetation for habitat or are found adjacent to vegetation in estuaries.Murphy, M.D., Muller, R.G., McLaughlin, B. 1994. A stock assessment of Southern Flounder and Gulf Flounder. Florida Marine Research Institute, St. Petersburg, Florida. Juveniles inhabit high salinity seagrass beds and older adults occur offshore in deeper depths. It undergoes ontogenetic shifts in dietary preference, feeding on amphipods and small crustaceans at small sizes, and feeding primarily on fishes as adults. Adults spend most of the year in bays and estuaries, migrating into deeper offshore waters to spawn during fall and winter (peaking between late October-mid-December). Specimens with ripe gonads have been collected at depths of 20–40 m in the eastern Gulf of Mexico. Larvae migrate inshore during January–February. The age at maturity for females is 1 year (FWRI 2010) with all mature by 2 years and size at 50% maturity is 35–38 cm TL. Males reach maturity between 30–35 cm TL. Females grow faster and larger than males. Longevity for males is 8–11 years and females is 7 years (Munroe 2002).

Fishing

They are a common sport fish that can be readily caught with dead fish (such as mullet), live bait, or even artificial or frozen baits such as shrimp or clams. A common way of catching this flounder is by spearfishing or jigging. Commercial fishermen are permitted to take up to 50 lbs of flounder species as by-catch per trip. The Gulf States Marine Fisheries Commission is currently conducting stock assessments for gulf and southern flounder populations in the Gulf of Mexico, which will inform the development of a fishery management plan. This species is commercially and recreationally exploited as a foodfish. It is caught using trawl, gill net, gig, hook-and-line, and trammel net. As with ''P. lethostigma'', this species is harvested using gill nets in estuaries.

Depth

Gulf flounder appear to prefer the ocean floor and camouflage against areas to stealthily strike their prey. This demersal species'' ''occurs in shallow depths within estuaries and coastal environments; it is most commonly found on the continental shelf at depths of 18–92 m, but has been collected to about 130 m.

Threats

This is a commercially and recreationally important species, particularly in Florida. It is also taken as by-catch in commercial trawl fisheries, particularly the penaeid shrimp fishery. Seagrass beds have experienced historical declines off Florida, especially in Florida Bay. The large seagrass die-off in Florida Bay between 1987-1995 was likely caused by salinity stress, turbidity, and algal blooms.Hall, M.O., Durako, M.J., Fourqurean, J.W. and Zieman, J.C. 1999. Decadal changes in seagrass distribution and abundance in Florida Bay. ''Estuaries'' 22(2B): 445-459. Over that decade, the standing crop of ''Thalassia testudinum'' declined by 28%, ''Halodule wrightii'' by 92%, and ''Syringodium filiforme'' by 88%. Since then, the decline has slowed, but die-off continues to occur. Between 1995-2003, turtle and shoal grass abundance increased with improved water clarity and has remained generally stable. Tampa Bay and Sarasota Bay also experienced significant seagrass declines in the 1980s, but has since recovered following the improvement of waste water management. It has been recorded in the diet of the invasive Lionfish,Dahl, K.A. and Patterson III, W.F. 2014. Habitat-Specific Density and Diet of Rapidly Expanding Invasive Red Lionfish, ''Pterois volitans'', Populations in the Northern Gulf of Mexico. ''PLOS ONE'' 9(8): e105852. which occurs throughout the entire depth range of'' P. albigutta''.

References

External links

*

{{Taxonbar, from=Q5617558

Gulf flounder
Fauna of the Southeastern United States
Fish of the Gulf of Mexico
Gulf flounder