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''Fundulus pulvereus'', the bayou killifish or bayou topminnow, is a small, topminnow-like fish that thrives primarily in the shallow waters off the shores of the Americas, as well as fresh and brackish waters. Feeding off of small vertebrates and invertebrates, this fish displays reproduction techniques unique to its species.〔 A member of the family Fundulidae, the bayou killifish belongs to one of the most common orders of fish, Cyprinodontiformes, which includes most small aquarium topminnows and North American killifish. Discovered in 1892, the bayou killifish is one of over 1000 species of killifish, and remains a thriving species amongst many others in the oceans. Its scientific name derives from the Latin word "fundus," which literally means "bottom," and many view this as ironic since the fish is a type of topminnow. However, the name was coined for a bottom species of the Atlantic coast, being the least important of the fundulus mudfish. Bayou killifish are fairly small, and only grow to a maximum length of . Given its size, the bayou killifish is fairly easy to spot in its natural environment. Living mostly in shallow waters, the male bayou killifish displays bright striped patterns of silver and olive-green, while the females are uniquely spotted.〔 ==Description and identification== Although most killifish belonging to the ''Fundulidae'' family share similar characteristics, the Bayou Killifish displays its own set of definitive markings that contrast it from other closely related species of topminnows and killifish. ''F. pulvereus'' has a body shape resembling that of a minnow that one may see in a small tidal pool near an ocean, but it is usually easier to spot because of its size. Unlike many other minnows, the Bayou Killifish usually grows to a maximum length of , enabling it to have the size it needs to defend itself, as well as the maneuverability of a much smaller fish.〔 All Bayou Killifish, both male and female, can be distinguished from other species of fish by their wide mouth.〔 ''F. pulvereus'' displays sexual dimorphism, which is a physical difference between males and females of the same species of animal. Sexual Dimorphism usually occurs in many species for various biological reasons pertaining to the species. Many animals use sexual dimorphism as a means of self-defense, or simply to attract mates or food sources. In Bayou Killifish, males usually tend to have a much more elongated body than females, as well as more characteristic markings. Males display an olive-green coloration on the top half of the body near the dorsal fin, with gold sides and a silvery bottom. Sometimes, the males will have a dark spot on or near the rear dorsal fin, just above dark vertical stripes that line the gold sides. Female bayou killifish, however, are usually somewhat smaller than the males, and display dark spots all over their body—a characteristic unique to the females. Accompanying these spots are faint, often broken vertical stripes along the dorsum of the fish.〔 Another distinguishing characteristic of the bayou killifish also belongs to the subgenera that it belongs to, "Fundulus." All seven species belonging to this subgenera, including ''F. pulvereus'', are native to the Gulf coast and Atlantic waters of North America. What makes them different from other killifish species is the formation of the maxilla, a bone that helps form the upper jaw of the fish. In ''F. pulvereus'' and other species belonging to the subgenera "Fundulus", the maxilla has a distinctly concave edge near the back of the bone, toward the brain. In other species belonging to different subgenera, the maxilla may not be concave at all. Instead, they possess a straightened maxilla with no concavity towards the anterior. The purpose of the concavity in the maxilla of ''F. pulvereus'' is relatively unknown. However, if one were to study the morphology and skeletal structures of many different species of killifish carcasses, they would easily be able to pick out ''F. pulvereus'' because of their distinctive maxilla. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Fundulus pulvereus」の詳細全文を読む スポンサード リンク
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