endemic to a single nation
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: Range includes the north-central coast of the Gulf of Mexico at sporadic sites between Galveston Bay, Texas, and Escambia Bay, Florida (Simpson and Gunter 1956, Hoese and Moore 1977, Thompson 1980, Gilbert 1992). Most records are between southeastern Louisiana and Florida. Lee et al. (1980) showed no collection sites between Galveston Bay and southeastern Louisiana. This may represent a sampling artifact, but Simpson and Gunter (1956) suggested that this distribution pattern is accurate (Gilbert and Relyea 1992).
- Robins, C.R. and G.C. Ray 1986 A field guide to Atlantic coast fishes of North America. Houghton Mifflin Company, Boston, U.S.A. 354 p. (Ref. 7251)
Length: 6 cm
Catalog Number: USNM 45562
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Fishes
Collector(s): B. Evermann
Year Collected: 1891
Locality: Galveston Bay, Texas., Texas, United States, Galveston Bay, Gulf of Mexico, Atlantic
Habitat Type: Freshwater
Comments: This species prefers cord grass (Spartina) marsh with a salinity below 20 parts per thousand and is most abundant at 1-4 parts per thousand (Lee et al. 1980, Robins et al 1986). It is characterized as a small, schooling fish that can occur in large numbers in quiet fresh waters, bays, saltwater marshes, tidal creeks, estuaries, and lagoons. It is not found on reefs or far away from shore (Robins et al. 1986). Exact habitat requirements are poorly known.
Depth range (m): 1 - 1
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Non-Migrant: No. All populations of this species make significant seasonal migrations.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 21 - 80
Comments: This species is known from about two dozen collection sites from eastern Texas to western Florida; exact number of occurrences is unknown..
Comments: About one-third of the 108 museum records tabulated to date contained between 10-99 individuals. This was the rarest cyprinodontid collected among sixty stations from the Rio Grande to the Sabine River (400 miles). Only 24 species were collected among six stations (Simpson and Gunter 1956). It is even rarer in Florida as evidenced by the presence of only seven specimens from Florida in the Florida Museum of Natural History collection (Gilbert and Relyea 1992). However, it may be locally more common in the Escambia River (Bailey et al. 1954).
Among the relatively early collections there are only two with more than 20 specimens. One was taken in two consecutive years (1950 and 1951) in and around Dickinson Bayou, near Dickinson, Texas (with a total of 24 specimens taken at six of 84 collections by Simpson and Gunter 1956). Another was made from in a stretch of the Escambia River (80 specimens reported by Bailey et al., 1954). Most records of greater than 20 specimens per lot are concentrated in eastern Louisiana, Mississippi, and Alabama, with Mississippi localities yielding as many as 270 specimens per lot (TU 138528) from a flood pool of the Biloxi River. Another very large lot (TU 130128) of 220 specimens was collected in St. Louis Bay at Bayou Portage, less than 45 km away. All but eight of the 21 lots with more than 25 specimens are from Mississippi, and all remaining large lots were collected either less than about 125 km to the west (Denis Pass and Ft. Jackson, Louisiana) or less than about 125 km to the east (Fish River, Alabama draining eastern Mobile Bay and the Escambia River in western Florida). Although the identification of specimens in these larger lots has not yet been checked, all were collected and identified by ichthyologists with considerable experience with coastal fishes and are presumed to be correctly identified. The species has recently been taken from a bayou of the Pascagoula River (Poss 1998). Peterson and Ross (1991) collected 240 individuals among three sites at Old Fort Bayou, Mississippi between 29 June 1995 and 20 September 1996. One individual was collected at the tidal freshwater site, 192 individuals were collected from the oligohaline site, and 47 individuals were collected from the mesohaline site.
National NatureServe Conservation Status
Rounded National Status Rank: N3 - Vulnerable
NatureServe Conservation Status
Rounded Global Status Rank: G3 - Vulnerable
Reasons: Patchy distribution within a small range along the coast of Gulf of Mexico; may be declining due to pollution and habitat destruction; local populations are relatively vulnerable to extirpation with a reduced capacity for re-colonization
Other Considerations: Nothing is known of reproductive biology. Data for other species in the genus suggest that fecundity is unlikely to exceed several hundred eggs/year and that individuals live their lives in a small area. Significant genetic mixing of geographically disparate populations resulting from movements of breeding individuals over significant distances would not be expected. Thus, local populations are relatively vulnerable to extirpation with a reduced capacity for re-colonization (Poss 1998). Listed by the state of Florida as a Threatened Species (Gilbert and Relyea 1992).
Global Short Term Trend: Relatively stable to decline of 30%
Comments: Populations may be declining due to pollution and habitat loss. The rate of decline in unknown but probably less than 30 percent over 10 years or three generations.
Degree of Threat: B : Moderately threatened throughout its range, communities provide natural resources that when exploited alter the composition and structure of the community over the long-term, but are apparently recoverable
Comments: Pollution and habitat destruction are major threats. Habitat alteration is the most serious threat. In areas associated with the Lower Mississippi River delta system, land loss from coastal erosion is rapidly destroying the marsh surface that is part of the necessary habitat of this species. Conversion of marsh to deeper, open water eliminates the marsh surface that, when flooded, provides important feeding, shelter, and possible breeding areas for saltmarsh topminnows. Erosion of marsh areas on several of Louisiana's barrier islands has completely eliminated several locations where this species has been collected in the past. Conversion of marsh surface associated with estuarine streams and meanders to nonflooded "fast-lands" also threatens this species. Disposal of dredged materials also will interrupt or destroy habitat in that flooding is reduced or eliminated, thus restricting its use by this species. [source: http://www.nmfs.noaa.gov/prot_res/species/fish/saltmarsh_topminnow.html]
In general, killifishes are commonly used for bait; important as experimental animals; also popular as aquarium fishes.
Management Requirements: Construction of new habitat for this species could be part of a management solution for enhancing this species' population stability. Coastal restoration construction projects are being implemented to reverse habitat alteration and destructive loss of marsh along the coast of the Gulf of Mexico, particularly in Louisiana. Whether programs designed to restore coastal marsh will be successful in providing habitat for the saltmarsh topminnow has not yet been demonstrated (http://www.nmfs.noaa.gov/prot_res/species/fish/saltmarsh_topminnow.html).
Biological Research Needs: Studies of the life history and population ecology of this species should be undertaken, with voucher materials in limited numbers taken to ensure accurate identification. Efforts are required to educate field workers in numerous disciplines and occupations to be aware of the species' potential presence and to ensure correct identification, without significantly depleting local populations (Gilbert and Relyea 1992, Poss 1998).
Global Protection: Few (1-3) occurrences appropriately protected and managed
Comments: Known to occur within at least one managed area, but no other protected occurrences are known.
Needs: As a more complete understanding of the microhabitat requirements of this species becomes available, activities that adversely affect marsh grasses should be restricted, especially during the most critical stages of the life cycle (Poss 1998).
The saltmarsh topminnow is a U.S. National Marine Fisheries Service Species of Concern. Species of Concern are those species about which the U.S. Government’s National Oceanic and Atmospheric Administration, National Marine Fisheries Service, has some concerns regarding status and threats, but for which insufficient information is available to indicate a need to list the species under the U.S. Endangered Species Act (ESA).
Saltmarsh topiminnows have little color in life; there is cross-hatching on the back and sides that may be gray-green or fainter and 12 to 30 dark round spots are often arranged in rows along the midside of the body from above the pectoral fin to the base of the caudal fin.
Saltmarsh topminnows live in estuaries, coastal salt marshes and back water sloughs including shallow tidal meanders of Spartina marshes. They are endemic to brackish water areas from Galveston Bay, Texas to Escambia Bay in the western panhandle of Florida.
Habitat alteration, dredging, and marsh erosion are the most serious threats to the saltmarsh topminnow.
IUCN: Not Evaluated
American Fisheries Society: Threatened in Florida, Vulnerable elsewhere
Species of Greatest Conservation Need: FL, LA, MS.
In 2006 the Species of Concern Grant program funded the Mississippi Department of Marine Resources for the study: “Fundulus jenkinsi, Saltmarsh Topminnow: Conservation Planning and Implementation”.
NMFS. Species of Concern Fact Sheet. 2008
Names and Taxonomy
Comments: Included in the subgenus Zygonedes by Brown (1957), Rosen (1973), and Wiley (1986), but allozyme data indicate that jenkinsi is more closely related to members of the subgenus heteroclitus and macrolepidotus (Cashner et al. 1992; see also Lee et al. 1980 and Gilbert and Relyea 1992).
The genus heteroclitus and macrolepidotus was removed from Atheriniformes:Cyprinodontidae and placed in Cyprinodontiformes:Fundulidae by Parenti (1981); pending confirmation based on other character suites, this change was not accepted in the 1991 AFS checklist (Robins et al. 1991).
See Wiley (1986) for a study of the evolutionary relationships of heteroclitus and macrolepidotus topminnows based on morphological characters. See Cashner et al. (1992) for an allozyme-based phylogenetic analysis of the genus heteroclitus and macrolepidotus.
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