Nueces roundnose minnow

Nueces roundnose minnow
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Division: Teleostei
Order: Cypriniformes
Family: Leuciscidae
Subfamily: Pogonichthyinae
Genus: Dionda
Species:
D. serena
Binomial name
Dionda serena
Girard, 1856

The Nueces roundnose minnow (Dionda serena) is a species of freshwater ray-finned fish in the family Leuciscidae, the shiners, daces and minnows. It is endemic to the upper Nueces in Texas.

Taxonomy

The Nueces roundnose minnow was first described by Charles Girard in his 1856 publication Researches upon the cyprinoid species inhabiting the fresh waters of the United States west of the Mississippi valley. The etymology of the species name "serena" meaning fair, as in coloration, is thought to refer to a lighter complexion compared with the closely related and easily mistaken Roundnose minnow (Dionda episcopa).

Molecular DNA surveys have verified the species classification of the Nueces roundnose minnow from similar Dionda species, as well as delimiting its native range.

Description

Girard's original description of the refers to the fish as having a slender body. The coloration of the minnow is light brown dorsal region with silver flanks and belly, separated by black scales along the lateral line extending through the eye to the nose. The fish also has a black spot at the base of the caudal fin. The maximum size of the fish is 3 inches. Other features of the minnow include its subterminal mouth, 34-40 lateral line scales and 7 anal fin soft rays.

Diet

A gut content analysis conducted by Katerina Cohen analyzed the stomach contents of three individual Nueces roundnose minnows. Her analysis determined that the bulk of the diet of the individuals examined was amorphous detritus (53.7% ±27.4) followed by picoplankton (21.3% ± 12.6) and diatoms (18.7% ± 8.9), particularly Cymbelloids (14.5% ± 7.6).

Habitat

The minnow is endemic to the Nueces River drainage unit and in particular is restricted to spring-fed areas with minimal seasonal temperature variation. Furthermore, they favor rocky pools and areas with filamentous algae growth.

The photo shows a shoal Nueces roundnose minnows in their habitat within the Frio River.

Conservation

Listed as "Least concern" by the IUCN, the conservation status of D. serena is somewhat disputed. It is classified by the state of Texas as S2 imperiled.

References

  1. ↑ NatureServe (2013). "Dionda serena". IUCN Red List of Threatened Species. 2013 e.T202092A15364520. doi:10.2305/IUCN.UK.2013-1.RLTS.T202092A15364520.en. Retrieved 18 November 2021.
  2. ↑ Fricke, Ron; Eschmeyer, William N. & van der Laan, Richard (eds.). "Species in the genus Cyprinella". Catalog of Fishes. California Academy of Sciences. Retrieved 10 March 2025.
  3. 1 2 Froese, Rainer; Pauly, Daniel (eds.). "Dionda serena". FishBase. August 2011 version.
  4. ↑ Girard, Charles (1857). "Researches upon the cyprinoid species inhabiting the fresh waters of the United States west of the Mississippi valley, from specimens in the museum of the Smithsonian Institution". Proceedings of the Academy of Natural Sciences of Philadelphia. 8. Academy of Natural Sciences of Philadelphia: 177.
  5. 1 2 3 Hendrickson, Dean A.; Cohen, Adam E.; Urban, Tomislav (2026-03-23). "Fishes of Texas Project Database and Website (Version 3.10)". www.fishesoftexas.org. Retrieved 2026-06-23.
  6. ↑ Schönhuth, Susana (January 2012). "Phylogeny, diversity, and species delimitation of the North American Round-Nosed Minnows (Teleostei: Dionda), as inferred from mitochondrial and nuclear DNA sequences". Molecular Phylogenetics and Evolution. 62 (1): 427–446. Bibcode:2012MolPE..62..427S. doi:10.1016/j.ympev.2011.10.011. PMID 22056492 – via Science Direct.
  7. ↑ Cohen, Katrina (May 2008). GUT CONTENT AND STABLE ISOTOPE ANALYSIS OF EXOTIC SUCKERMOUTH CATFISHES (HYPOSTOMUS) IN THE SAN MARCOS, TX: A CONCERN FOR SPRING ENDEMICS?. Texas State University-San Marcos.
  8. ↑ "NatureServe Explorer 2.0". explorer.natureserve.org. Retrieved 2026-06-23.