Golden shiner

Golden shiner fish
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Cypriniformes
Family:	Cyprinidae
Genus:	Notemigonus Rafinesque, 1819
Species:	N. crysoleucas
Binomial name
Notemigonus crysoleucas (Mitchill, 1814)

The golden shiner (Notemigonus crysoleucas) is a cyprinid fish native to eastern North America. It is the sole member of its genus. Much used as a bait fish, it is probably the most widely pond-cultured fish in the United States.

Description

Though it has been known to reach lengths of 30 cm (12 in), in the wild the golden shiner is usually between 7.5 and 12.5 cm (3 to 5 inches) long. The body is laterally compressed (deep-bodied). The back is dark green or olive, and the belly is a silvery white. The sides are silver in smaller individuals, but golden in larger ones. There can be a faint dusky stripe along the sides. The anal fin is large and has 8-19 rays, while the dorsal fin comprises almost always 8 rays. Scales are relatively large and easily lost when the fish is handled. The mouth is small and upturned. Two characteristics can distinguish the golden shiner from all other minnows: (1) the lateral line has a pronounced downward curve, with its lowest point just above the pelvic fins; and (2) there is a fleshy keel lacking scales on the belly between the pelvic fins and the base of the anal fin.

Distribution

The golden shiner is found throughout the eastern half of North America, north to the St Lawrence River, Great Lakes, and Lake Winnipeg, and west to the Dakotas and Texas. Because of its use as bait, it has also been introduced in many places outside this native range.

Habitat

Golden shiners prefer quiet waters and are therefore found in lakes, ponds, sloughs, and ditches. They are sometimes found in the quietest parts of rivers. They do better in clear water with dense mats of vegetation, but can deal with pollution, turbidity, and low oxygen content. They can tolerate temperatures as high as 40 °C (104 °F) which is unusually high for a North American minnow.^[1]

Diet

Golden shiners are omnivorous. They eat zooplankton, insects, plants, and algae. They can feed at the surface, in mid-water, or at the bottom. They can locate prey visually, or filter-feed on high-density zooplankton without resorting to visual cues.^[2] They are themselves food for all manner of game fish such as trout and bass, hence their popularity as bait fish.

Reproduction

Golden shiners lay sticky eggs amid vegetation. There is no parental care. Occasionally, like a few other minnows, golden shiners can deposit their eggs in the occupied nests of pumpkinseed, largemouth bass or bowfin (the latter two, ironically, can be predators of shiners).^[3] This behaviour is called egg dumping and resembles the brood parasitism of birds such as cuckoos, inasmuch as the shiner eggs will benefit from the parental care that pumpkinseed, largemouth bass, and bowfin provide to the content of their nests. As opposed to parasitism by cuckoos, however, the parent's eggs do not suffer from the presence of parasitic eggs, and may actually benefit from a dilution effect when predators attack the brood.^[4]

Behaviour

Golden shiners live in large groups (shoals) that roam widely. Several laboratory studies have shown that the movements of a shoal can be determined by a minority of individuals at the front of it. For example, an individual that know when and where food is available within a large tank can lead many other fish to the right place at the right time of day.^[5] If all fish have similar knowledge, there is still a tendency for some individuals to be found always at the front of a moving shoal, possibly because they are intrinsically hungrier and more motivated to find food.^[6] Small fish are also found more often at the front of a shoal than larger fish, again possibly because they are more motivated to find food.^[7]

Like other minnows, golden shiners are sensitive to the release of an alarm substance, or Schreckstoff, contained within special skin cells. If a predator catches and bites into a minnow, the skin is broken, the substance is released, and other minnows in the vicinity can detect the substance and react to it by leaving the area. The substance can also survive intact in the feces of a predator, and minnows can thus detect the presence of a minnow-eating predator through the presence of its feces. In the laboratory, golden shiners were found to react strongly to water that contained feces from snakes that had eaten other golden shiners, but not nearly as much to water laden with feces from snakes that had eaten green swordtails, a fish that does not possess an alarm substance.^[8]

Like other fishes, golden shiners have a good daily time sense and can anticipate the arrival of food when this food is made available at the same time of the day or night.^[9] They can also do this when there is more than one mealtime a day.^[10] This anticipation is expressed as swimming and positioning towards the food source, and other naive individuals can perceive this and join the anticipating fish in the hope of sharing its food.^[11]

Golden shiners are also capable of time-place learning (associating different places with different times of day). They can be taught to feed in one part of an aquarium in the morning and a different part in the afternoon; or to feed in one part in the morning, a different part at mid-day, and back to the first part in the afternoon.^[12]

References

1. ^ Coad, B.W., Waszczuk, H., and Labignan, I., 1995, Encyclopedia of Canadian fishes, Canadian Museum of Nature.
2. ^ Reebs, S.G., 2002, Plasticity of diel and circadian activity rhythms in fishes, Reviews in Fish Biology and Fisheries 12: 349-371.
3. ^ Shao, B., 1997, Nest association of pumpkinseed, Lepomis gibbosus, and golden shiner, Notemigonus crysoleucas, Environmental Biology of Fishes 50: 41-48; Katula, R.S., and Page, L.M., 1998, Nest association between a large predator, the bowfin (Amia calva), and its prey, the golden shiner (Notemigonus crysoleucas), Copeia 1998, 220-221; Kramer, R.H., and Smith, L.L. Jr., 1960, Utilization of nests of largemouth bass, Micropterus salmoides, by golden shiners, Notemigonus crysoleucas, Copeia 1960, 73-74.
4. ^ Shao, B., 1997, Effects of golden shiner (Notemigonus crysoleucas) nest association on host pumpkinseeds (Lepomis gibbosus): evidence for a non-parasitic relationship, Behavioral Ecology and Sociobiology 41, 399-406.
5. ^ Reebs, S.G., 2000, Can a minority of informed leaders determine the foraging movements of a fish shoal? Animal Behaviour 59: 403-409.
6. ^ Leblond, C., and S.G. Reebs, 2006, Individual leadership and boldness in shoals of golden shiners (Notemigonus crysoleucas), Behaviour 143: 1263-1280.
7. ^ Reebs, S.G., 2001, Influence of body size on leadership in shoals of golden shiners, Notemigonus crysoleucas, Behaviour 138: 797-809.
8. ^ Godard, R.D., Bowers, B.B., and Wannamaker, C., 1998, Responses of golden shiner minnows to chemical cues from snake predators, Behaviour 135: 1213-1228.
9. ^ Reebs, S.G., and M. Laguë, 2000, Daily food-anticipatory activity in golden shiners: a test of endogenous timing mechanisms, Physiology and Behavior 70: 35-43; Laguë, M., and S.G. Reebs. 2000, Phase-shifting the light-dark cycle influences food-anticipatory activity in golden shiners, Physiology and Behavior 70: 55-59.
10. ^ Laguë, M., and S.G. Reebs, 2000, Food-anticipatory activity of groups of golden shiners during both day and night, Canadian Journal of Zoology 78: 886-889.
11. ^ Reebs, S.G., and B.Y. Gallant, 1997, Food-anticipatory activity as a cue for local enhancement in golden shiners (Pisces: Cyprinidae, Notemigonus crysoleucas), Ethology 103: 1060-1069.
12. ^ Reebs, S.G, 1996, Time-place learning in golden shiners (Pisces: Notemigonus crysoleucas), Behavioral Processes 36: 253-262.

• "Notemigonus crysoleucas". Integrated Taxonomic Information System. http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=163368. Retrieved 18 April 2006. 
• William F. Sigler and John W. Sigler, Fishes of the Great Basin (Reno: University of Nevada Press, 1987), pp. 188-191.
• Froese, Rainer, and Daniel Pauly, eds. (2006). "Notemigonus crysoleucas" in FishBase. April 2006 version.