endemic to a single nation
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: Atlantic and Gulf slope drainages from Edisto River, South Carolina, to Amite-Comite river system, Louisiana. Ranges south to upper St. Johns River system in peninsular Florida. Common.
Length: 8 cm
Habitat and Ecology
Habitat Type: Freshwater
Comments: Creeks and small to medium rivers, usually in moderate current in sand-gravel runs and rocky riffles, near vegetation (Page and Burr 1991).
Depth range (m): 0.505 - 0.505
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.
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.
Life History and Behavior
Single clutch of eggs laid in July-August. Some evidence of females spawning twice, but few survive to a 2nd spawning season.
Molecular Biology and Genetics
Barcode data: Noturus leptacanthus
Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
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Download FASTA File
Statistics of barcoding coverage: Noturus leptacanthus
Public Records: 8
Specimens with Barcodes: 8
Species With Barcodes: 1
IUCN Red List Assessment
Red List Category
Red List Criteria
National NatureServe Conservation Status
Rounded National Status Rank: N5 - Secure
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Total adult population size is unknown but relatively large.
Trend over the past 10 years or three generations is uncertain but likely relatively stable or slowly declining.
Comments: Localized threats may exist, but on a range-wide scale no major threats are known.
The Speckled Madtom (Noturus leptacanthus) is one of the 324 fish species found in Tennessee.
The speckled madtom (Noturus leptacanthus) is a North American fish that belongs to the Noturus genus of the Ictaluridae family. It is characterized by being a dark reddish brown color with a dusky or mottled caudal fin with a pale border, and also by the toxic sting from the pelvic and pectoral fins associated with the genus Noturus.The average size of this fish is between 39 and 50mm; however, the longest ever recorded specimen was 110mm. The average life span is 2.5 to 3 years. Because of having such a short life, they become mature by their second summer. Their diet consists mostly of midge larvae. The speckled madtom is found in the Southeastern United States from Tennessee to Florida and the states in between including South Carolina, Georgia, Alabama, and Mississippi. They tend to thrive in small to medium-sized moderately swift moving streams over gravel or boulder riffle. The study done in 1978 by Clark indicated that they spawn during the early summer in discarded cans or bottles that are free of debris due to the nest preparation activities of the males. Specialized management is not required for this species, which is why it has such a healthy population across its range. 
Geographic Distribution of Species
The speckled madtom has a wide range throughout the southeastern United States. In Tennessee it is found only in the Canasauga River system, where it is abundant.It is also found in Atlantic and Gulf slope drainages from the Edisto River in South Carolina to the Amite-Comite River system of Louisiana. The St. Johns River system in the Florida peninsula makes up the southernmost area of their range. In total they are found in abundant numbers throughout Louisiana, Mississippi, Alabama, Georgia, Florida, South Carolina and Tennessee. The natural distribution of this species has not declined much, if any.
The speckled madtom inhabits small to moderate sized streams and is normally a creek species. They often inhabit very shallow riffles with sand, rock or gravel bottoms. During the day speckled madtoms will rest in areas with aquatic vegetation such as pondweed or bur-weed. However, due to their nocturnal feeding patterns, they will leave these areas at night to go feed. Feeding begins at dusk and the amount of food in their stomach will increase until dawn when the feeding stops. Their diet is mostly insect larvae, especially midge larvae. They detect their food with their sensory barbels, and their vision undoubtedly plays little part in their feeding behavior. Major competition for the speckled madtom comes from other species from the Noturus genus. The only known predators of the speckled madtom are the rock bass, Ambloplites rupestris, and larger Noturus species. In order to protect themselves from predation, all Noturus species have developed a venomous sting from their pectoral spines. The level of toxicity varies among each species and it was found that the speckled madtom did not have a high level of toxicity. Human influences such as pollution that would kill aquatic vegetation would be detrimental to the population of this species.
The spawning period for the speckled madtom is from May through August with water temperatures ranging from 20-24°C. The speckled madtom is one of the least fecund species of freshwater North American fishes. They normally spawn two clutches per year with each clutch consisting of 14-45 eggs. Their eggs are very large relative to their body size, with the average size being 5.5mm in diameter. It is believed that the large egg size compensates for the extremely small clutch size. The large egg size allows for the larvae to be very large and well developed upon hatching. The average size of 1 year old is 39mm, and the average size of a 2 year old is 50mm. They reach sexual maturity by their second summer and have a maximum lifespan of just over 2 years. The speckled madtom is known to nest inside of discarded cans and bottles that are cleared of debris and silt by the male. The male then guards the eggs without feeding for around 2.5 weeks. This species is unique in that pollution of cans and bottles actually provides more nesting opportunity, which could increase the populations.
Currently, there is no widespread management in effect for the speckled madtom. The population of this species is steady throughout its range and shows no signs of major decline. While there may be localized threats to this species, there is no widespread threat that is known.Localized threats could include things such as habitat destruction, which takes place everywhere on some scale. It is not known as a sport fish, so overfishing is not an issue. However, it has been noted that many fisherman like to use this species as bait. Also, hybridization has not been found to be an issue due to the unique spawning patterns and habits of the speckled madtom. Due to their toxic and sharp spines, over predation is not a huge issue for this species either. The largest threat for this species would be habitat destruction or loss of flow in streams. In order to make sure this population stays at a healthy size, we must make sure we don’t destroy loads of habitat and/or use our water resources irresponsibly. Also, it was shown in the Chattahoochee River system that agricultural land use increases the number of speckled madtoms in the streams. Agriculture has been known to hurt many species because of runoff, but the speckled madtom is more abundant in areas with agricultural land use. There are no agencies or non-governmental groups that are actively protecting this species, so the management and protection of this species will largely be the responsibility of individual people and the decisions they make.
In order to manage this species, it would be necessary to have a good idea of how many fish there are in different areas of its range. I would start by taking samples from multiple streams in each watershed. I would conduct these samples by using seines in shallow riffle areas with dense aquatic vegetation. This method would be used during the day and anytime between late August and late June. I would not want to do this during the mating season due to the fact that the males not readily leave the nest, and it really isn’t known how they respond after being taken from their nest. Also, at night I would use different types of traps to try to trap these fish while they are foraging for food. Once there was a definitive result on the number of these fish in each watershed, we could determine the areas that need management. One of the best ways to manage this species is to increase aquatic vegetation that they rely on for foraging and protection from the few predators they have. The only area I would consider setting aside as a protected watershed would be the Conasauga River system in Tennessee. The reason is because this is the only area where this species is found in Tennessee, and it is much more common in every other state within its range.
- Williams, James D., National Audubon Society Field Guide to Fishes. 2nd ed. New York: Alfred A. Knopf, 2011. 181. Print.
- Clark, K. E., Reproduction of the Speckled Madtom, Noturus leptacanthus. Journal of the Mississippi Academy of Sciences 22 (1977). 108pp.
- Etnier, David A., and Wayne C. Starnes., The Fishes of Tennessee. Knoxville, Tennessee: The University of Tennessee Press, 2001. 321-22. Web. 20 Nov. 2013.
- Noturus leptacanthus. Encyclopedia of Life, n.d. Web. 21 Nov. 2013. .
- Speckled Madtom. Florida Museum of Natural History, n.d. Web. 21 Nov. 2013. .
- Ross, Stephen T., Inland Fishes of Mississippi. Jackson, Mississippi: Mississippi Department of Wildlife, Fisheries, and Parks, 2001. 323-24. Web. 20 Nov. 2013.
- Clark, Kathleen E., Ecology and Life History of the Speckled Madtom, Noturus leptacanthus [Ictaluridae]. 1978
- Reed, Hugh D., The Poison Glands of Notorus and Schilbeodes. The American Naturalist 41(1907): 553-566.
- Walser, C A., H. L. Bart., Influence of Agriculture on In-Stream Habitat and Fish Community Structure in Piedmont Watersheds of the Chattahoochee River System. Ecology of Freshwater Fish 8.4 (1999): 237-246
- Bulger, Angela G., Edds, David R., Population Structure and Habitat Use in Neosho Madtom (Noturus placidus). The Southwestern Naturalist 46 (2001): 8-15
Names and Taxonomy
Comments: See Grady and LeGrande (1992) for a study of phylogenetic relationships, modes of speciation, and historical biogeography of Noturus madtom catfishes. See Lundberg (1992) for a synthesis of recent work on the systematic relationships of ictalurid catfishes.