Apeltes is a monospecific genus old ray-finned fish belonging to the family Gasterosteidae, the sticklebacks. The only species in the genus is A. quadracus, the fourspine stickleback or bloody stickleback, which lives in freshwater, brackish and benthopelagic environments of the northwestern Atlantic Ocean between Newfoundland and South Carolina.
Appearance
.]]The fourspine stickleback is the smallest member of
Gasterosteidae.
It typically has either four or five dorsal spines, but may have as many as seven.
It has an elongated body that is spotted brown to olive green except for the underside. Its belly is silvery white. Males tend to be darker than females and develop red pelvic spines.
The first three dorsal spines are close together and stick out at acute angles, each with a triangular membrane.
[ The fourth spine is straight and associated with the dorsal fin. Its lateral line ends blow the origin of the second dorsal fin. Its pelvic fins sit almost right below the pectoral fins in the thoracic region. The species does not have scales.][Bigelow, H. B., & Schroeder, W. C. (1953). Fishes of the Gulf of Maine (Vol. 53). Washington: US Government Printing Office.] They usually grow to be about 4 centimeters, but can reach 5 to 6 centimeters in length.
Distribution
The species is found from Newfoundland and Quebec[ southward to North Carolina,][Burgess, G. H., and D. S. Lee. 1978. Apeltes quadracus (Mitchill), fourspine stickleback, p. 561. In: Atlas of North American Freshwater Fishes. D. S. Lee, C. R. Gilbert, C. H. Hocutt, R. E. Jenkins, D. E. McAllister, and J. R. Stauffer, Jr. (eds.). North Carolina State Museum of Natural History, Raleigh, North Carolina.] living close to freshwater shores in well-vegetated areas. It has been introduced to a few freshwater bodies in Pennsylvania, Alabama, New Jersey, and in Lake Superior.
Ecology
Fourspine sticklebacks are largely solitary, spending most of their time near the bottom of lakes. Their diet consists of microscopic invertebrates and plankton.[ Fourspine stickleback typically breed at one year of age, though some individuals may survive to breed again at age two.][Craig, D., & FitzGerald, G. J. (1982). Reproductive tactics of four sympatric sticklebacks (Gasterosteidae). Environmental Biology of Fishes, 7(4), 369–375.] Their breeding season lasts from April until late July, often breeding at the same time and location as three other stickleback species (threespine, ninespine, and blackspotted stickleback).[Worgan, J. P., & FitzGerald, G. J. (1981). Habitat segregation in a salt marsh among adult sticklebacks (Gasterosteidae). Environmental Biology of Fish, 6, 105–109.] Males establish territories and construct nests of vegetation either on the bottom or on underwater structures,[ and may construct as many as five stacked nests.][Reisman, H.M. 1963. Reproductive behaviour of Apeltes quadracus, including some comparisons with other Gasterosteid fishes. Copeia, 1, 191–192.] Once he has attracted a female and fertilized her eggs, the male watches over the nest until the eggs hatch.[ Females may produce several clutches of eggs per year.][Wootton, R. J. (1984). A functional biology of sticklebacks. University of California Press.]
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