Family : Sticklebacks and tubesnouts ;
Common Names in English:
Unarmored Threespine Stickleback, Unarmoured Threespine Stickleback
Species Gasterosteus aculeatus williamsoni
Threespine sticklebacks are laterally compressed
shaped fish with three sharp, erectile
spines at the forward part
of the dorsal fin. The pelvic fin usually consists of a spine on
each side and one fin
ray. Modified scales
form a single row
along the length
of the body. Although the unarmored threespine
stickleback has some of the characteristics of threespine sticklebacks,
it is noticeably different from other subspecies
in several ways.
The most important are that the dorsal and pelvic
spines are substantially
shorter and most specimens either completely lack or have very few
scales or lateral
plates, thus the name
Sticklebacks have black to dark olive backs with silvery white sides and white to gold bellies. At spawning time males develop a red throat and belly, the usually clear fins take on a green hue, and the eyes become blue. Females develop a light red or pink throat and belly.
This species may reach a length of 58 mm (2.3 in), but most are less than 50 mm (2 in). Females tend to be slightly larger than males.
Although most species of stickleback can adapt to salt, brackish
or fresh water
, unarmored threespine sticklebacks appear to be limited
to fresh water. They require clear, flowing, well-oxygenated water
with associated pools
and eddies of quiet water and areas of dense
vegetation or debris
to provide adequate cover
and food supply.
Sticklebacks are one of the most studied fishes by ichthyologists and behaviorists. Some researchers believe that the two lineages of marine and freshwater sticklebacks are an example of evolution in action since records indicate that some of their adaptations have occurred in only the past 10 years. This species is quite habitat specific and does not do well in other than their preferred surroundings.
Typically found at an altitude of 0 to 272 meters (0 to 892 feet).
Biome: Marine .
Sticklebacks are voracious omnivores and feed on a variety of food including some algae and invertebrates such as insects, snails, small crustaceans, and some types of small worms. Males sometimes feed on stickleback eggs that are not properly guarded. Because they are visual feeders , they require relatively clear water in order to see their food source.
A male first establishes a selected territory that he vigorously
protects. He then excavates
a small depression
in the sand
he builds a nest
out of fragments of aquatic plants
, and debris
. After cementing the materials
together with mucus
threads spun from his kidneys
, he burrows through it to make an exit
and entrance and weights
the nest with pebbles
. While building
the nest he aggressively defends it against other males and not-as-yet
welcome females. Courtship
begins when the nest is ready.
Next he searches for a receptive female. When a female carrying eggs enters his territory the male swims near her in a zigzag dancing movement. If the female is attracted, she follows him to his nest where she deposits her eggs. The male immediately fertilizes them and drives the female away. Over the course of the breeding season , the male may entice several other females into his nest.
The male protects the eggs and the fry from predators . During the incubation period he fans the eggs with his pectoral fins to keep them clean and to provide a fresh supply of oxygenated water. Incubation time varies with temperature but is generally 6-8 days. After hatching the fry stay in the nest for a few days getting nutrition from their attached yolk sac . When they start to leave the nest area in search of food, the male continues to protect them, sometimes taking them into his mouth to return them to the nest. When dispersed from the nest they feed in the cover of dense vegetation.
Male sticklebacks are very territorial when breeding and actively protect their nests , eggs , and young, using their spines as weapons in offense and defense. Confronted by intruders or predators , they assume a threatening posture, and rush forward with raised dorsal spines and a wide, gaping mouth . If the intruder is still not intimidated, the stickleback becomes very still, points its head down , and jerks its body as if to bore a hole in the ground below. This display seems to be effective in driving intruders away. In off-spawning seasons they are much less territorial and may even show schooling tendencies.
- Whittaker & Margulis,1978
- C. Linnaeus, 1758
- (Hatschek, 1888) Cavalier-Smith, 1983
- Grobben, 1908
- (Haeckel, 1874) Cavalier-Smith, 1998
- Bateson, 1885
- Cuvier, 1812
- Jawed Vertebrates
- Huxley, 1880
- Huxley, 1880
- Subclass: Actinopterygii ()
- Class: Osteichthyes () - Huxley, 1880
- Superclass: Osteichthyes () - Huxley, 1880
- Infraphylum: Gnathostomata () - auct. - Jawed Vertebrates
- Subphylum: Vertebrata () - Cuvier, 1812 - Vertebrates
- Phylum: Chordata () - Bateson, 1885 - Chordates
- Infrakingdom: Chordonia () - (Haeckel, 1874) Cavalier-Smith, 1998
- Branch: Deuterostomia () - Grobben, 1908
- Subkingdom: Bilateria () - (Hatschek, 1888) Cavalier-Smith, 1983
- Kingdom: Animalia () - C. Linnaeus, 1758 - animals
Gasterosteus williamsoni Girard
Members of the genus Gasterosteus
ZipcodeZoo has pages for 26 species and subspecies in this genus:
G. aculeatus (Three Spined Stickleback) · G. aculeatus aculeatus (Banstickle) · G. aculeatus santaeannae (Santa Ana Stickleback) · G. aculeatus williamsoni (Unarmored Threespine Stickleback) · G. canadus (Black King Fish) · G. carolinus (Carolina Pompano) · G. crenobiontus (Techirghiol Stickleback) · G. ductor (Pilot Fish) · G. gymnurus (Western Threespine Stickleback) · G. inconstans (Common Freshwater Stickleback) · G. islandicus (Iceland Stickleback) · G. japonicus (Japanese Pineconefish) · G. laevis (Smoothtail Ninespine Stickleback) · G. microcephalus (West Coast Threespine Stickleback) · G. ovatus (Short Dorsal Fin Pompano) · G. platygaster (Southern Nine-Spined Stickleback) · G. platygaster aralensis (Aral Stickleback) · G. pungitius (Nine-Spined Stickleback) · G. quadracus (Four-Spined Stickleback) · G. saltatrix (Santa Ana Stickleback) · G. sinensis (Amur Nine-Spined Stickleback) · G. spinachia (Fifteen-Spined Stickleback) · G. trachurus (Sakhalin Nine-Spined Stickleback) · G. volitans (Ornate Butterfly-Cod) · G. wheatlandi (Black-Spotted Stickleback) · G. williamsoni (Unarmoured Threespine Stickleback)
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- 1994 IUCN red list of threatened animals Gland, Switzerland: IUCN, 1993 url p. 230.
- Bulletin of the Southern California Academy of Sciences Los Angeles, Calif.: The Academy, 1971- url , p. 125, p. 126, p. 154, p. 157, p. 160, p. 75, p. 93, p. 96.
- California fish and game. [San Francisco, etc.]: State of California, Resources Agency, Dept. of Fish and Game. url p. 166, p. 169, p. 173, p. 175.
- Current bibliography for aquatic sciences and fisheries. London, Taylor & Francis ltd. url p. 52.
- Syllogeus. Ottawa, National Museum of Natural Sciences, 1972-1995. url p. 88.
- The Great Basin naturalist. 47 1987 Provo, Utah: M.L. Bean Life Science Museum, Brigham Young University, 1939-1999. url p. 546.
- Threatened wildlife of the United States. Washington, Bureau of Sport Fisheries and Wildlife [for sale by the Supt. of Docs., U.S. Govt. Print. Off.]1973. url p. 53.
- Aquarium of the Pacific
- Brands, S.J. (comp.) 1989-present. The Taxonomicon. Universal Taxonomic Services, Zwaag, The Netherlands. Accessed January 14, 2012.
- Global Biodiversity Information Facility. Accessed March 14, 2008. http://www.gbif.org Mediated distribution data from 2 providers.
- Kottelat, Maurice (from FishBase).
- Biodiversity Heritage Library NamebankID: 2492816
- Catalogue of Life Accepted Name Code: Fis-46970
- Fishbase Species ID: 6302
- Global Biodiversity Information Facility Taxonkey: 2481042
- Integrated Taxonomic Information System (ITIS) Taxonomic Serial Number (TSN): 201979
- U.S. Fish and Wildlife Service Species Identifier: E00X
- Zipcode Zoo Species Identifier: 111042