Aphredoderus sayanusPirate perch(Also: Pirate perch)

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Geographic Range

Aphredoderus sayanus is found only in North America and is believed to have occupied the Mississippi Valley before the ancestors of most modern-day fishes had migrated into the region (Pflieger, 1975). Today pirate perch are found throughout the lowlands and surrounding areas of the southeastern Ozarks, in lakes and pools east of the Mississippi River and as far south as eastern Texas. (Pflieger, 1975)

Habitat

Pirate perch are found in clear warm water with low currents; these include bottomland lakes, overflow ponds and the quiet pools and backwaters of low-gradient streams (Pflieger, 1975). Within these areas pirate perch tend to congregate where there is dense vegetation, woody debris, root masses and undercut banks (Monzyk et al., 1997). (Monzyk, et al., 1997; Pflieger, 1975)

  • Aquatic Biomes
  • lakes and ponds
  • rivers and streams

Physical Description

Pirate perch are unusual in that their urogenital opening is positioned far anteriorally under the throat (Fletcher, et. Al. 2004). This feature is not present in juveniles, as the anus migrates with maturity. Pirate perch are grayish with black speckles and have a narrow, vertical, dark bar at the base of the tail fin and under the eye (Pflieger, 1975). Pirate perch have a single dorsal fin and ctenoid scales on the head and body. The tail fin is slightly notched, not deeply forked. The gill cover has a sharp spine. Dorsal and anal fins each have 2 or 3 weak spines at front (Pflieger, 1975). The mouth is moderately large with a slightly projecting lower jaw (Clay, 1962). The lateral line is incomplete or underdeveloped in pirate perch from the Midwest, but specimens closer to the Atlantic coast show a much better developed lateral line (Eddy, 1969). Pirate perch are sexually dimorphic with females being larger and more full-bodied than males (Tiemann, 2004). (Clay, 1962; Eddy, 1969; Fletcher, et al., 2004; Pflieger, 1975; Tiemann, 2004)

  • Sexual Dimorphism
  • female larger
  • sexes shaped differently
  • Range length
    6.35 to 12.7 mm
    0.25 to 0.50 in
  • Average length
    6.1 mm
    0.24 in

Development

Larval pirate perch look very similar to adults, except in the placement of the anus. Prolarvae and early postlarvae have 12-15 preanal and 13-196 postanal myomeres (Hogue, 1976). Once these fish reach 13 mm, the number of preanal myomeres will decrese as the anus begins migration toward the gular region (Hogue, 1976). (Hogue, 1976)

Reproduction

It was first suggested that the migration of the anus in A. sayanus was to facilitate gill brooding of its eggs, as is found in northern cavefishes (Amblyopsis spelaea) with similar morphological features. However it was noted that the space within the branchial cavity of A. sayanus is insufficient to hold an entire clutch of eggs (Katula, 1992). Pirate perch actually spawn in underwater root masses and use their forward facing urogenital pores to deposit eggs and release sperm into the floating canopy (Fletcher et al., 2004). Fletcher (2004) observed that, within an assemblage, pirate perch were often of distinct developmental stages, strongly implying that the eggs had been deposited and/or fertilized during multiple spawning events. (Fletcher, et al., 2004; Katula, 1992)

Male pirate perch guard nests from other males wishing to fertilize the eggs. These behaviors are aggressive and probably relate to selection pressures imposed by intense competition for fertilization success in group spawning (Fletcher et al., 2004). (Fletcher, et al., 2004)

Spawning generally occurs in May in floating root masses parallel to water flow. Female clutch size is about 100-400, depending on body size; in a single root mass, up to 2000 total offspring were found to be present in a single nest. Female pirate perch thrust their heads and release their eggs into the root masses and males congregate there to fertilize them (Fletcher et al., 2004). (Fletcher, et al., 2004)

  • Breeding interval
    Breeding occurs once yearly.
  • Breeding season
    Spawning occurs during the spring.
  • Range number of offspring
    100 to 400

The extent of parental involvement in the rearing of pirate perch is debated. Some sources suggest that parents guard the nest until the larvae are a little less than a centimeter long (Forbes and Richardson, 1920). However, more recent papers suggest that there is no evidence of extended parental care (Fletcher et al., 2004). (Fletcher, et al., 2004; Forbes and Richardson, 1920)

  • Parental Investment
  • no parental involvement
  • pre-fertilization
    • provisioning
    • protecting
      • female

Lifespan/Longevity

Maximum longevity in the wild is 4 years (Pflieger, 1975). (Pflieger, 1975)

  • Range lifespan
    Status: wild
    unknown to unknown years
  • Average lifespan
    Status: wild
    4 years
  • Range lifespan
    Status: captivity
    unknown (low) hours
  • Average lifespan
    Status: captivity
    4 years
    AnAge

Behavior

Pirate perch are solitary fish (Fletcher et al., 2004). They are carnivorous, feeding mostly at night (Clay, 1962). Indeed, pirate perch got their name from C.C. Abbott, who observed that these fish eat all other suitably sized fish when confined in an aquarium (Forbes and Richardson, 1920). Pirate perch appear to have a life history strategy similar to those of sunfishes, moving into the limnetic zone immediately after hatching and remaining there for several weeks before returning to the littoral zone (Fontenot and Rutherford, 1999). (Clay, 1962; Fletcher, et al., 2004; Fontenot and Rutherford, 1999; Forbes and Richardson, 1920)

Communication and Perception

In addition to the lateral line sensory system present in most fishes, an extensive array of sensory pores on the head of A. sayanus may enable these nocturnal fishes to navigate in the dark (Fletcher et al., 2004). There is little known about communication in this species. (Fletcher, et al., 2004)

Food Habits

This carnivorous fish eats primarily immature aquatic insects, small crustaceans and sometimes small fish (Pflieger, 1975). (Pflieger, 1975)

  • Animal Foods
  • fish
  • insects
  • aquatic crustaceans

Predation

In the root masses that the pirate perch use for spawning, adult and juvenile salamanders, as well as eastern dobsonfly larvae (Corydalus cornutus), have been found. It is unclear whether these animals are predators of the eggs or not (Fletcher, et al 2004). Adult pirate perch may be eaten by larger fish, piscivorous birds, otters or mink. (Fletcher, et al., 2004)

Ecosystem Roles

Pirate perch are solitary and secretive, hiding during the daylight hours in thick growths of aquatic plants or accumulations of organic debris. They are mainly active at night (Pflieger, 1975). Pirate perch impact the populations of their small, invertebrate prey. (Clay, 1962; Pflieger, 1975)

Economic Importance for Humans: Positive

Pirate perch are not widely used as food or recognized as game fish.

Economic Importance for Humans: Negative

There are no known negative impacts of pirate perch on humans.

Conservation Status

Pirate perch are not generally common because they occupy relatively uncommon habitats. Within those habitats however they are abundant. In one study in Arkansas pirate perch were the most common species found in their sampling, representing 21% of 8,113 fish taken (Killgore and Baker, 1996). In Ohio pirate perch are considered endangered. Development has significantly impacted the habitats of pirate perch because the bottomland lakes and ponds they occupy have been extensively destroyed by dredging, ditch construction, draining and siltation (Trautman, 1957). (Killgore and Baker, 1996; Ohio Division of Wildlife, 2000; Trautman, 1957)

Contributors

Tanya Dewey (editor), Animal Diversity Web, Courtney Egan (editor).

Meghan Miner (author), University of Michigan-Ann Arbor, Kevin Wehrly (editor, instructor), University of Michigan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

external fertilization

fertilization takes place outside the female's body

fertilization

union of egg and spermatozoan

freshwater

mainly lives in water that is not salty.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

insectivore

An animal that eats mainly insects or spiders.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

vibrations

movements of a hard surface that are produced by animals as signals to others

References

2006. "Merriam Webster Online" (On-line). Accessed September 12, 2006 at http://m-w.com/dictionary/urogenital.

Clay, W. 1962. A Field Manual of Kentucky Fishes. Frankfort, KY: Kentucky Department of Fish and Wildlife Resources.

Eddy, S. 1969. How to know the Freshwater Fishes: Second Edition. Dubuque, IA: Wm. C. Brown Company Publishers.

Fletcher, D., E. Dakin, B. Porter, J. Avise. 2004. Spawning Behavior and Genetic Parentage in the Pirate Perch (Aphredoderus sayanus), a Fish with an Enigmatic Reproductive Morphology.. Copeia, 1: 1-10.

Fontenot, Q., D. Rutherford. 1999. Observations on the Reproductive Ecology of Pirate Perch Aphredoderus sayanus . Journal of Freshwater Ecology, Vol. 14 no. 4: 545-550.

Forbes, S., R. Richardson. 1920. Fishes of Illinois. Springfield, IL: Illinois State Journal Co., State Printers.

Hogue, J. 1976. Preliminary Guide to the Identification of Larval Fishes in the Tennessee River. Tennessee: Tennessee Valley Authority Division of Forestry, Fisheries, and Wildlife Development.

Katula, R. 1992. The Spawning Mode of the Pirate Perch. Trop. Fish Hobby, 40: 156-159.

Killgore, K., J. Baker. 1996. Patterns of larval fish abundance in a bottomland hardwood wetland. Wetlands, Vol. 16, no. 3: 288-295.

Monzyk, F., W. Kelso, D. Rutherford. 1997. Characteristics of Woody Cover Used by Brown Madtoms and Pirate Perch in Coastal Plain Streams. Transactions of the American Fisheries Society, 126: 665-675.

Ohio Division of Wildlife, 2000. "Ohio Biological Survey" (On-line). Biodiversity in Ohio. Accessed December 07, 2005 at http://www.ohiobiologicalsurvey.org/biodiv-v6n2.html.

Pflieger, W. 1975. The Fishes of Missouri.. Missouri: Missouri Department of Conservation.

Tiemann, J. 2004. Observations of the pirate perch, Aphredoderus sayanus (Gilliams), with comments on sexual dimorphism, reproduction, and unique defecation behavior.. Journal of Freshwater Ecology, 19(1): 115-121.

Trautman, M. 1957. The Fishes of Ohio. Baltimore, MD: Ohio State University Press.