Fundulus pulvereus

Last updated

Fundulus pulvereus
Fundulus pulvereus.jpg
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Cyprinodontiformes
Family: Fundulidae
Genus: Fundulus
Species:
F. pulvereus
Binomial name
Fundulus pulvereus
(Evermann, 1892)
Synonyms [2]
  • Zygonectes pulvereusEvermann, 1892
  • Fundulus spilotus Holbrook, 1863
  • Zygonectes funduloidesEvermann, 1892
  • Fundulus funduloides(Evermann, 1892)
  • Fundulus limbatus Krøyer, 1896

The bayou killifish or bayou topminnow (Fundulus pulvereus) is a 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. [3]

Contents

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 7 centimetres (2.8 in). 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. [4]

Description and identification

Although most killifish belonging to the family Fundulidae 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. It 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 5–7 centimetres (2.0–2.8 in), enabling it to have the size it needs to defend itself, as well as the maneuverability of a much smaller fish. [5] All bayou killifish, both male and female, can be distinguished from other species of fish by their wide mouth. [6]

Bayou killifish display sexual dimorphism, which is a physical difference between males and females of the same species of animal. In the species, 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. [6]

Another distinguishing characteristic of the bayou killifish is also seen in the rest of its genus. All seven species belonging to Fundulus, including the bayou killifish, are native to the Gulf coast and Atlantic waters of North America. What makes them different from other killifish genera 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 a Fundulus species because of their distinctive maxilla. [7]

Habitat and diet

Just as the name implies, the bayou killifish predominates many freshwater and brackish environments such as bays, marshes, swamps, and bayous along the Atlantic coast. [6] However, due to a remarkable adaptation of the killifish's lungs, the species is also capable of inhabiting marine environments such as saltwater marshes and oceans. [3] The bayou killifish is a non-seasonal killifish, meaning that it is non-migratory, and thus occupies the same territories within the Western Atlantic waters of both Americas year round. [5] Most populations of bayou killifish can be found in the temperate coastal waters of the Atlantic coast of North America, as well as the Gulf of Mexico. [3] They often inhabit moderately warm waters with temperatures ranging from 15–26 °C (59–79 °F). [5] Shallower waters such as marshes and bays along the coast serve as suitable habitats for Bayou Killifish because of the absence of unstable isotopes and fluctuating pHs that are often found in deeper and more fluent water habitats. [3] These shallow environments provide a sufficient amount of bacteria that thrive in unstable conditions with questionable isotope ratios, and thus provide a steady system of bacterial degradation that in turn stabilizes conditions suitable for bayou killifish. [3]

Because many of these fish live in marsh-type environments, their main food source consists of small aquatic insects and isopods. Isopods, small crustaceans that usually live on the bottom of freshwater and marine environments, serve as the primary food source for the bayou killifish for several reasons. Dating back to Carboniferous period 300 million years ago, many aquatic isopods have evolved to live in unstable environments. Isopods can withstand high radiation contamination as well as unstable isotope levels in water. Therefore, they thrive in many of the unstable conditions where bayou killifish live, serving as a convenient food source for these fish. Predation is not a major problem for F. pulvereus, as nothing consumes them as a steady food source. Thus, the bayou killifish has a stable population that is invulnerable to predators. [5]

Reproduction

Many biologists studying the bayou killifish consider their reproduction one of the most important concepts of the species to understand, because most of the fish's behavior is based on its reproduction habits. Bayou killifish reproduce sexually and are oviparous, meaning that they give birth via laying eggs. This is a characteristic that most of the fish in the order Cyprinodontiformes share, though some may be viviparous. Little is known about the spawning seasons of the bayou killifish, however, biologists do know that this species of killifish spawns mainly during the spring, more specifically during the spring tides—periods of 3 to 6 days biweekly, that occur in a period known as the semi-lunar phase. Biologists conclude that this tide-associated spawning may be a common component in the reproductive strategies and behaviors of most, if not all, cyprinodontids of North America. Although many studies have been conducted involving the reproduction of these killifish, few findings have been made referring to the full reproductive habits of the Bayou Killifish. Future studies and research is crucial to understanding these creatures, and more importantly their well-being in future generations. Entire populations of F. pulvereus rely on its reproductive habits and behaviors. [4]

Biological status

F. pulvereus can withstand many biological and environmental stresses such as habitat degradation, predation, and limited food sources, due mainly to its evolution within certain habitats. Bayou Killifish have a very specific diet, but one that happens to contain a plethora of microorganisms that are crucial to its existence. F. pulvereus lives in primarily hostile environments, so predation is not necessarily an issue for survival. However, these fish are susceptible to the parasitic fluke worm, Calyptospora funduli. Common among many fish, especially Cyprinodontids, F. pulvereus has a very high rate of inhabitants of this parasite, with approximately 31% naturally infected. While serving as a host for the worm, Bayou Killifish are not vectors for the worm and thus cannot spread them to other organisms. The parasite can have many effects on the intestinal fortitude and reproductive abilities of the killifish, though current studies have shown little effect of Calyptospora funduli on the Bayou Killifish. Unlike fish who belong to one of the largest orders of vertebrates, Perciformes, killifish like F. pulvereus belonging to the orders Atheriniformes and Cyprinodontiformes are not naturally resistant to the infestation of Calyptospora funduli. Possibly a future threat for the Bayou Killifish C. fuduli shows no recent negative impact on F. pulvereus other than taking up significant space in the digestive tract. Other than a future mishap with this parasitic fluke worm, few threats are known to exist for the Bayou Killifish. F. pulvereus is a very stable species, and shows no degradation in the near future. [8]

Similar species

Males are similar in structure and appearance to the longnose killifish, with the bayou killifish being distinguishable by their thicker stripes. Bayou killifish also resemble the diamond killifish, but have no pointed snout as the diamond killifish does. All bayou killifish are easy to identify, and distinguishable enough to stand out from any other type of killifish or topminnow. [6]

Interesting facts

Related Research Articles

<span class="mw-page-title-main">Cyprinodontiformes</span> Order of fishes

Cyprinodontiformes is an order of ray-finned fish, comprising mostly small, freshwater fish. Many popular aquarium fish, such as killifish and live-bearers, are included. They are closely related to the Atheriniformes and are occasionally included with them. A colloquial term for the order as a whole is toothcarps, though they are not actually close relatives of the true carps – the latter belong to the superorder Ostariophysi, while the toothcarps are Acanthopterygii.

<span class="mw-page-title-main">Mummichog</span> Species of fish

The mummichog is a small killifish found along the Atlantic coast of the United States and Canada. Also known as Atlantic killifish, mummies, gudgeons, and mud minnows, these fish inhabit brackish and coastal waters including estuaries and salt marshes. The species is noted for its hardiness and ability to tolerate highly variable salinity, temperature fluctuations from 6 to 35 °C, very low oxygen levels, and heavily polluted ecosystems. As a result, the mummichog is a popular research subject in embryological, physiological, and toxicological studies. It is also the first fish ever sent to space, aboard Skylab in 1973.

<span class="mw-page-title-main">Killifish</span> Any of various oviparous cyprinodontiform fish

A killifish is any of various oviparous (egg-laying) cyprinodontiform fish, including families Aplocheilidae, Cyprinodontidae, Fundulidae, Profundulidae and Valenciidae. All together, there are 1,270 species of killifish, the biggest family being Rivulidae, containing more than 320 species. As an adaptation to living in ephemeral waters, the eggs of most killifish can survive periods of partial dehydration. Many of the species rely on such a diapause, since the eggs would not survive more than a few weeks if entirely submerged in water. The adults of some species, such as Kryptolebias marmoratus, can additionally survive out of the water for several weeks. Most killies are small fish, from 2.5 to 5 centimetres, with the largest species growing to just under 15 centimetres (6 in).

<i>Fundulus</i> Genus of fishes

Fundulus is a genus of ray-finned fishes in the superfamily Funduloidea, family Fundulidae. It belongs to the order of toothcarps (Cyprinodontiformes), and therein the large suborder Cyprinodontoidei. Most of its closest living relatives are egg-laying, with the notable exception of the splitfin livebearers (Goodeidae).

<span class="mw-page-title-main">Fundulidae</span> Family of fishes

Fundulidae is the family of topminnows and North American killifishes.

<span class="mw-page-title-main">Blackstripe topminnow</span> Species of fish

The blackstripe topminnow, Fundulus notatus, is a small freshwater fish in the family Fundulidae, found in central North America.

The Barrens topminnow is a species of freshwater fish in the family Fundulidae, which is in need of management so that it may continue to and increasingly survive in the wild. There are many potential causes of decline of this species including the invasive western mosquitofish that will replace native species on a population level, wadding piscivorous birds preying on adults, and the overall restricted distribution of the species. Managing for this species is vital for its success, but to do so there must be an understanding of the species' characteristics. It is endemic to a small portion of Tennessee in the Elk River and the West Hickory creek of the Cumberland river drainage. living up to only 3 years the life span of F. julisia is very short. In many cases the majority of the population does not even reach that age. Most adult males are eaten by birds because of their bright coloration during breeding season. Current management plans are in place for the improvement of the species such as captive breeding and reintroduction, and also private management of streams and land. Yet, more can be done to aid them in their survival efforts. Buffer zones around streams can be created to promote the health of the stream and close observation of the introduced populations needs to be a priority. With only three small original populations left in the wild it is important that species survive in captivity, but more so in its natural environment.

<span class="mw-page-title-main">Saltmarsh topminnow</span> Species of fish

The saltmarsh topminnow is a species of killifish for the family Fundulidae. It occurs in the costal wetlands of the Gulf of Mexico in the United States.

The Bermuda killifish is a small fish which is endemic to the islands of Bermuda in the western Atlantic Ocean. It belongs to the genus Fundulus in the killifish and topminnow family, Fundulidae.

<i>Fundulus dispar</i> Species of fish

The Starhead topminnow is a native United States species that ranges from the Ouachita River drainage in Louisiana, the Big Black river in Mississippi, and extends northward into the Mississippi River and Lake Michigan basins to the southern Michigan and southern Wisconsin areas. The Starhead topminnow is endangered due to the removal of aquatic vegetation and the continued development of land that infringes on its habitat.

The blackspotted topminnow, Fundulus olivaceus, is a species of fish in the family Fundulidae: the topminnows and North American killifishes. It is native to the south-central United States, where it is known from the drainages of the Mississippi River from Illinois to the Gulf of Mexico and as far west as Galveston Bay.

<span class="mw-page-title-main">Southern studfish</span> Species of fish

The southern studfish is a ray-finned fish of the family Fundulidae, the tooth carps, that is native to the southeastern United States.

<span class="mw-page-title-main">Plains topminnow</span> Species of fish

The plains topminnow is a species of freshwater topminnow found in North America. The fish has a small range within the United States of America which consists of two major populations.

The diamond killifish is a species of North American killifish found in salt marshes, hypersaline flats and mangrove along the Gulf Coast of the United States. This species grows to a length of 6 cm (2.4 in). It is found in the aquarium trade. It was previously recognized as, Adinia xenica, the only known member of its genus. Nucleotide analyses has reevaluated the phylogeny of the Funduliidae and placed the diamond killifish into the Fundulus genus.

<span class="mw-page-title-main">Gulf killifish</span> Species of fish

The Gulf killifish is one of the largest members of the genus Fundulus; it is capable of growing up to 7 inches (18 cm) in length, whereas the majority of other Fundulus reach a maximum length of 4 inches (10 cm). Therefore, F. grandis is among the largest minnows preyed upon by many sport fish, such as flounder, speckled trout, and red drum. Fundulus derives from the Latin meaning "bottom," and grandis means "large". The Gulf killifish is native to the Gulf of Mexico from Texas to Florida and the eastern coast of Florida and the Caribbean Sea in the Atlantic Ocean. Threats to the survival of the Gulf killifish include extreme changes in salinity, changes in temperatures, and toxic events such as the hypoxic dead zone in Louisiana and the Deepwater Horizon oil spill. The Gulf killifish is currently being used to test the effects of oil and oil dispersants on the physiology of marine species affected by these substances. This is significant to conservation biology, because with the continued extraction of oil and other natural resources from North American waters, it has become increasingly important to understand the risks and consequences in worst-case scenarios, such as the Deepwater Horizon oil spill, and the lasting effects on the marine ecosystem.

<i>Aphanius danfordii</i> Species of fish

Aphanius danfordii, the Kızılırmak toothcarp or Sultan Sazlığı toothcarp, is a species of killifish belonging to the family Cyprinodontidae. It is endemic to the Kızılırmak River and the upper Seyhan River drainage systems and is now restricted to a few locations in the Sultan Sazlığı marshes. Though little data is available, the population of the fish seems to be declining. The International Union for Conservation of Nature has rated its conservation status as being "critically endangered" and fears it may become extinct in the wild if the drainage of the marshes continues.

<i>Fundulus nottii</i> Species of fish

Fundulus nottii, the bayou topminnow or southern starhead topminnow, is a fish of the family Fundulidae [1] found in the southeastern United States.

<i>Fundulus luciae</i> Species of fish

The spotfin killifish is a member of the genus Fundulus. This hardy fish is notable for spending its entire life in sporadically flooded salt marsh habitat, sheltering in shallow pools, puddles, and small tidal rivulets. It closely resembles the mummichog in shape and coloration, but the two species can be distinguished by dorsal fin ray count: 8–9 in the spotfin versus 11–12 in the mummichog. Additionally, the dorsal fin of F. luciae originates farther back, and slightly behind the anal fin origin; in the mummichog, the dorsal fin begins anteriorly to the anal fin origin. The spotfin killifish is named for the pronounced ocellus found on the posterior dorsal fin of adult males. It is a small fish, seldom attaining 50 mm in total length. Its distribution extends along the U.S. east coast from Massachusetts to Georgia.

<span class="mw-page-title-main">Banded topminnow</span> Species of fish

The banded topminnow is a North American species of temperate freshwater killifish belonging to the genus Fundulus of the family Fundulidae.

<span class="mw-page-title-main">Russetfin topminnow</span> Species of fish

The russetfin topminnow is a North American species of temperate freshwater killifish belonging to the genus Fundulus of the family Fundulidae.

References

  1. ↑ Collette, B.B.; Grubbs, D.; Pezold, F.; Simons, J.; Caruso, J.; Carlson, J.; McEachran, J.D.; Brenner, J.; Tornabene, L.; Chakrabarty, P.; Robertson, R.; Jelks, H.; Espinosa-Perez, H.; Tolan, J.; Chao, L. (2015). "Fundulus pulvereus". IUCN Red List of Threatened Species . 2015: e.T196679A2473222. doi: 10.2305/IUCN.UK.2015-4.RLTS.T196679A2473222.en . Retrieved 20 November 2021.
  2. ↑ Froese, Rainer; Pauly, Daniel (eds.) (2019). "Fundulus pulvereus" in FishBase. August 2019 version.
  3. 1 2 3 4 5 Sullivan, Michael J.; Cynthia A. Moncreiff (1990). "Edaphic Algae Are an Important Component of Salt Marsh Food-webs: Evidence from Multiple Stable Isotope Analyses". Marine Ecology Progress Series. 62. 62: 149–159. Bibcode:1990MEPS...62..149S. doi: 10.3354/meps062149 .
  4. 1 2 Greeley, Mark S. Jr. (1984). "Spawning by Fundulus Pulvereus and Adinia Xenica (Cyprinodontidae) along the Alabama Gulf Coast Is Associated with the Semilunar Tidal Cycles". Copeia. 1984 (3): 797–800. doi:10.2307/1445175. JSTOR   1445175.
  5. 1 2 3 4 5 6 7 8 9 10 11 Froese, Rainer. "Fundulus pulvereus (Evermann, 1892) Bayou killifish". Academia Sinica. Retrieved February 10, 2013.
  6. 1 2 3 4 5 Bowling, Brenda. "Bayou killifish Fundulus pulvereus". Texas Parks and Wildlife Department. Retrieved February 10, 2013.
  7. ↑ Wiley, E. O. (1986). "A Study of the Evolutionary Relationships of Fundulus Topminnows (Teleostei: Fundulidae)". American Zoologist. 26 (1): 121–130. doi: 10.1093/icb/26.1.121 . JSTOR   3883190.
  8. ↑ Fournie, John W.; Robin M. Overstreet (1993). "Host Specificity of Calyptospora funduli (Apicomplexa: Calyptosporidae) in Atheriniform Fishes". Parasitology. 79 (5): 720–727. doi:10.2307/3283611. JSTOR   3283611. PMID   8410544 . Retrieved 20 February 2013.
  9. ↑ Nordlie, Frank G. (2006). "Physicochemical environments and tolerances of cyprinodontoid fishes found in estuaries and salt marshes of eastern North America" (PDF). Rev Fish Biol Fisheries. 16: 51–106. doi:10.1007/s11160-006-9003-0. S2CID   31813976 . Retrieved 20 February 2013.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.