Fundulus olivaceus

blackspotted topminnow

Type Locality

Florence, Lauderdale Co., AL (Storer 1845).

Etymology/Derivation of Scientific Name

Fundulus, from the Latin name Fundus, meaning “bottom,” the habitat; olivaceus Latin, meaning “olive-colored” (Pflieger 1997).

Synonymy

Paecilia olicacea Storer 1845b:51.

Zygonectes olivaceus Wailes 1854:335 (based on Agassiz 1584:353).

Fundulus olivaceus Cook 1959:153.

Characters

Maximum size: 97 mm TL (Braasch and Smith 1965).

Coloration: Spots on body distinct, color resembles lateral band. Distinct dark lateral band (Hubbs et al.1991). Pale brownish yellow to olive green dorsally with prominent black stripe on sides and black spots in dorsolateral area; breeding males develop dorsal and ventral projections from the black lateral band, and yellowish fins (Etnier and Starnes 1993).

Counts: 30-40 longitudinal scale rows (Hubbs et al 1991); 8-11 gill rakers; 8-9 (7-10) dorsal rays; 10-12 (10-13) anal rays, 12-14 pectoral rays, and 6 pelvic rays (Ross 2001).

Body shape: Elongate (Ross 2001).

Mouth position: Slightly supraterminal (Goldstein and Simon 1999).

External morphology: Gill slit extending dorsal to uppermost pectoral fin ray; distance from origin of dorsal fin to end of hypural plate less than distance from origin of dorsal fin to preopercle or occasionally about equal to that distance (Hubbs et al 1991). Dorsal and anal fins more elongate in males than in females (Ross 2001). Tubercles of nuptial males not prominent, occurring on the anal and dorsal fin rays, and as a row of about 5 setiform tubercles on body scales (Etnier and Starnes 1993).

Distribution (Native and Introduced)

U.S. distribution: Occurs in the central United States throughout the Mississippi and adjacent drainages (Hubbs et al 1991).

Texas distribution: Ranges from the San Jacinto Drainage north and eastward to the Red River Basin (Hubbs et al 1991).

Abundance/Conservation status (Federal, State, NGO)

Populations in Southern drainages are currently stable (Warren et al. 2000).

Habitat Associations

Macrohabitat: Prefers small to large fast-flowing, relatively clear, sand-gravel bottom streams (Shute 1980).

Mesohabitat: Often occurring along stream margins near thick stands of emergent vegetation (Shute 1980). In Village Creek (blackwater tributary of the Nueces River in Hardin County), Texas, Fundulus olivaceus 15-40 mm SL dominated both the summer and winter samples. F. olivaceus seemed to respond primarily to water depth; during summer and fall (lower discharge), species found primarily in sandbank habitats; during winter (increased discharge), species occupied backwaters, riffles and flooded riffles; during spring, species occupied sandbank and backwater habitats (Moriarty and Winemiller 1997). In the Upper Mississippi River Valley, species generally restricted to clear, fast, upland streams, which usually have some gravel or other hard bottom material and little vegetation (Braasch and Smith 1965). Laboratory experiments show species is able to tolerate salinities up to 24.8 ppt (Griffith 1974).

Biology

Spawning season: March - early September; peak spawning activity in May (Foster 1967; Thomerson and Wooldridge 1970; Blanchard 1996). In Village Creek, Hardin Co., Texas, Fundulus olivaceus 15-40 mm SL dominated both the summer and winter samples. Most ovaries from several adult females collected yielded two size classes of yolk-bearing eggs, large mature and smaller maturing eggs, indicative of a protractive reproductive season during which multiple egg cohorts are released (Moriarty and Winemiller 1997).

Spawning Habitat: Over gravel (Baugh 1981).

Spawning behavior: Baugh (1981) observed observed males chasing other males from spawning area by head-to-head or lateral displays, accompanied by flaring of the opercles or gular area. Males court females by active head-bobbing (Foster 1967). Baugh (1981) reported the male and female pair in close contact along their entire lengths while spawning over gravel. Based observations of a single pair in aquarium, the male swims parallel and slightly above the female, frequently making physical contact; the pair sometimes rotating horizontally; periodically, female flexes posterior half of body and sinks to substratum; male positions his flexed body alongside the female and both fish quiver strongly; an egg or eggs may be extruded and fertilized at this time; duration of pairing ranges 1-5 seconds and may be repeated many times in succession (Ross 2001).

Fecundity: Ripe eggs average 2.14 mm in diameter; outer egg membrane has filaments that tend to be restricted to one area, forming a tuft; eggs hatch in 10-14 days (Foster 1967; Blanchard 1996).

Age at maturation: 38-40 mm SL (Blanchard 1993; 1996).

Migration: NA

Growth and Population structure: Adult fish are usually 40-65 mm SL (Blanchard 1996). In Village Creek, Hardin Co., Texas, Fundulus olivaceus 15-40 mm SL dominated both the summer and winter samples.

Longevity: Etnier and Starnes (1993) suggest that life span is probably about 3 years (like F. notatus).

Food habits: Invertivore/herbivore (Goldstein and Simon 1999). Surface oriented predators that consume terrestrial arthropods including insects (mainly dipterans), spiders, isopods, and centipedes; all of which constitute about half of the diet; remainder of diet includes aquatic insects, microcrusteaceans (cladocerans), filamentous algae and other plant material (Thomerson and Wooldridge 1970; Petifils 1986).

Phylogeny and morphologically similar fishes

Subgenus Zygonectes (Shute 1980). Fundulus olivaceus hybridizes with F. notatus (Thomerson 1967). The distinct lateral stripe of F. olivaceus separates it from all other species of topminnow except the closely related F. notatus, the blackstripe topminnow, from which it differs in having more spots on the body (with the intensity of the spots equal to those of the lateral line), in lacking a predorsal stripe, and in having more distinct spots on the dorsal fin (with the spots usually extending to the fin margin; Ross 2001). In Texas, where the range of F. olivaceus overlaps with that of F. notatus the two species are usually ecologically separated, F. olivaceus being typically a quiet water form; F. olivaceus inhabits swifter waters near the coastal plain (Knapp 1953).

Host Records

Calyptospora funduli (Fournie and Overstreet 1993). Posthodiplostomum minimum (Mayberry et al. 2000).

Commercial or Environmental Importance

[Additional literature noting collection of this species from Texas locations includes, but is not limited to the following: Hubbs (1957); Setzer (1970).]

References

Agassiz, L. 1854. Notice on a collection of fishes from the southern bend of the Tennessee River, in the state of Alabama. Amer. J. Sci. Arts, ser. 2, 17:297-308, 353-369.

Baugh, T. M. 1981. Notes on the reproductive behavior of five species of the genus Fundulus in aquaria. Journal of Aquariculture. 2(4):86-89.

Braasch, M. E. and P. W. Smith. 1965. Relationships of the topminnows Fundulus notatus and Fundulus olivaceus in the Upper Mississippi River Valley. Copeia, 1965:46-53

Blanchard, T. A. 1993. Spawning cycles and microhabitat use of Fundulus olivaceus and Fundulus euryzonus (Cyprinodontidae). Master's thesis, S.E. Louisiana Univ., Hammond.

Blanchard, T. A. 1996. Ovarian cycles and microhabitat use in two species of topminnow, Fundulus olivaceus and F. euryzonus, from the southeastern United States. Environmental Biology of Fishes. 47:155-163.

Cook, F.A. 1959. Freshwater Fishes in Mississippi. Mississippi Game and Fish Commission, Jackson. 239 pp.

Etnier, D.A., and W.C. Starnes. 1993. The Fishes of Tennessee. The University of Tennessee, Knoxville. 681 pp.

Foster, N. R. 1967. Comparative studies on the biology of killifishes (Pisces, Cyprinodontidae). PhD. diss., Cornell Univ., Ithaca, N.Y.

Fournie, J.W., and R. M. Overstreet. 1993. Host specificity of Calyptospora funduli (Apicomplxa: Calyptosporidae) in Atheriniform fishes. J. Parisitol. 79(5):720-727.

Goldstein, R.M., and T.P. Simon. 1999. Toward a united definition of guild structure for feeding ecology of North American freshwater fishes. pp. 123-202 in T.P. Simon, editor. Assessing the sustainability and biological integrity of water resources using fish communities. CRC Press, Boca Raton, Florida.

Griffith, R.W. 1974. Environment and salinity tolerance in the genus Fundulus. Copeia 1974(2):319-331.

Hubbs, C. 1957. Distributional patterns of Texas fresh-water fishes. The Southwestern Naturalist 2(2-3):89-104.

Hubbs, C., R. J. Edwards, and G. P. Garrett. 1991. An annotated checklist of the freshwater fishes of Texas, with keys to identification of species. The Texas Journal of Science, Supplement 43(4):1-56.

Knapp, F.T. 1953. Fishes Found in the Freshwater of Texas. Ragland Studio and Litho Printing Co., Brunswick. 166 pp.

Mayberry, L. F., A. G. Canaris, and J. R. Bristol. 2000. Bibliography of parasites and vertebrate host in Arizona, New Mexico, and Texas (1893-1984). University of Nebraska Harold W. Manter Laboratory of Parasitology Web Server pp. 1-100.

Moriarty, L.J., and K.O. Winemiller. 1997. Spatial and temporal variation in fish assemblage structure in Village Creek, Hardin County, Texas. Texas Journal of Science, Supplement 49(3):85-110.

Petifils, L. E. 1986. Ecological relationships among members of the F. notatus species complex. Master's thesis, Univ. New Orleans, New Orleans, LA.

Pflieger, W. L. 1997. The Fishes of Missouri. Missouri Department of Conservation, Jefferson City. 372 pp.

Ross, S. T. 2001. The Inland Fishes of Mississippi. University Press of Mississippi, Jackson. 624 pp.

Setzer, P.Y. 1970. An analysis of a natural hybrid swarm by means chromosome morphology. Trans. Amer. Fish. Soc. 99(1):139-146.

Shute, J. R. 1980. Fundulas olivaceus (Storer), Blackspotted topminnow. pp. 523 in D. S. Lee, et al. Atlas of North American Freshwater Fishes. N. C. State Mus. Nat. Hist., Raleigh, i-r+854 pp.

Storer, D.H. 1845. [Description of a fish from Alabama River]. Proc. Boston Soc. Nat. Hist. 2:51-52.

Thomerson, J. E. 1967. Hybrids between the cyprinodontid fishes, Fundulus notatus and Fundulus olivaceus in southern Illinois. Ill. St. Acad. Sci. 60(4):375-379.

Thomerson, J. E. and D. P. Wooldridge. 1970. Food habits of allotopic and syntopic populations of the topminnows Fundulus olivaceus and Fundulus notatus. American Midland Naturalist. 84(2):573-576.

Wailes, B.L.C. 1854. Report on the Agriculture and Geology of Mississippi. E. Barksdale, State Printer, Jackson.

Warren, M.L. Jr., B.M. Burr, S. J. Walsh, H.L. Bart Jr., R. C. Cashner, D.A. Etnier, B. J. Freeman, B.R. Kuhajda, R.L. Mayden, H. W. Robison, S.T. Ross, and W. C. Starnes. 2000. Diversity, distribution and conservation status of the native freshwater fishes of the southern United States. Fisheries 25(10):7-29.