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Dionda argentosa
manantial roundnose minnow
Type Locality
San Felipe Creek and Devils
River (tributaries of the Rio Grande del Norte; Girard 1856).
Etymology/Derivation of Scientific Name
Dionda – from the
Greek Dione, the mother of Venus (Edwards 1999); argentosa –
silvery, referring to the sides and abdomen (Scharpf 2005). Common name of
this species “manantial” is a Spanish word that translates as “spring-run”,
referring to the habitat necessary for survival of this species (Hubbs et
al. 1991).
Synonymy
Dionda argentosa
Girard 1856:178; Hubbs et al. 1991:18; Gold et al. (1992); Mayden et al.
(1992).
Dionda episcopa Hubbs
and Brown (1956); Robinson (1959).
Characters
Maximum size: 75.9 mm
SL (Cantu and Winemiller 1997).
Coloration: A black
band through eye to snout; black caudal spot (Hubbs and Brown 1956; Hubbs et
al. 1991). Gilbert (1856) described coloration of the dorsal region as
reddish brown; sides and abdomen “as if painted over with silver or
quicksilver”; fins olivaceous.
Counts: Pharyngeal
teeth 0,4-4,0; 8 anal fin rays; 36-41 lateral line scales; fewer than 10
soft rays on dorsal fin (Hubbs and Brown 1956; Edwards 1999; Hubbs et al.
1991).
Mouth postion:
Subterminal (Schonhuth et al. 2008).
Body shape: Caudal
peduncle depth narrow; short postorbital; eye as long as snout; distance
from origin of anal fin to end of caudal peduncle contained two and one-half
or fewer times from tip of snout to origin of anal fin (Hubbs et al. 1991).
Girard (1856) described the species as having a small head and obtuse snout,
a rather slender and compressed body; the head constituting about 18%
(two-elevenths) of the total length.
External morphology:
Caudal spot rounded; first obvious dorsal
fin ray a thin splint, closely attached to the following well developed but
unbranched ray, especially at tip; lower lip thin, without a fleshy lobe;
lateral line usually not decurved, either straight or with a broad arch;
premaxillaries protractile; upper lip separated from the skin of snout by a
deep groove continuous across the midline; cartilaginous ridge of lower jaw
hardly evident and not separated by a definite groove from the lower lip
(Hubbs et al. 1991).
Internal morphology:
Intestinal canal long, more than twice the length of the body (Hubbs et al.
1991).
Distribution (Native and Introduced)
U.S. distribution:
Texas distribution:
Devils River, San Felipe and Sycamore creeks in Val Verde County (Hubbs et
al. 1991; Garrett et al. 1992). Schonhuth et al. (2008) reported collection
of this species from the lower Pecos River at Pandale, Val Verde Co. and
from San Felipe Spring, in Moore Park, Val Verde County.
Abundance/Conservation status (Federal, State, NGO)
Species is abundant in the
Devils River, San Felipe Creek, and Sycamore Creek and is not federally
protected (Cantu and Winemiller 1997; Garrett et al. 1992; Edwards et al.
2004). However, Edwards et al. (2004) stated that reductions in water
quality and/or quality could easily alter their status. Scharpf (2005)
listed species as imperiled.
Habitat Associations
Macrohabitat:
Spring-influenced waters headwaters and spring runs (Hubbs and Brown 1956;
Hubbs and Garrett 1990; Hubbs et al. 1991).
Mesohabitat: Adapted
to flood-prone environment (Harrell 1978); species primarily occupied
riffles prior to flooding in the Devils River, but shifted toward channel
habitat post-flooding. Cantu and Winemiller (1997) reported that species
occurred in most mesohabitats of the Devils River, but was not found in
isolated pools or a deep pool site which may indicate avoidance of large
predators. Hubbs and Brown (1956) reported that the species is restricted to
clear, spring-fed waters having little temperature variation.
Biology
Spawning season:
Collection of small individuals (< 15 mm SL) from fall – spring, with
highest incidence in winter, suggests that reproduction may peak during the
fall in the Devils River, Texas (Cantu and Winemiller 1997).
Spawning habitat:
Spawning Behavior:
Fecundity:
Age at maturation:
Migration:
Growth and Population
structure:
Longevity:
Food habits:
Phylogeny and morphologically similar fishes
D. argentosa and the
Devils River minnow (D. diaboli) are sympatric species in the Devils
River, Sycamore Creek and San Felipe Creek, Texas: adults of the former
species are much longer and stouter than those of D. diaboli; D.
argentosa has 36-41 lateral line scales versus 32-36 in D. diaboli;
and D. argentosa lacks the cross-hatched scales and double dashes
along the lateral line which are characteristic of D. diaboli
(Edwards 1999); the caudal spot is rounded in D. argentosa and is
wedge-shaped in D. diaboli (Hubbs et al. 1991). Dionda argentosa
and the roundnose minnow (D. episcopa) are very similar,
but the latter species is restricted to streams in the Pecos River were
D. argentosa is not found (Edwards 1999). The Nueces roundnose minnow (D.
serena) occurs only in the Nueces River system and has 7 anal fin rays
versus 8 anal fin rays in D. argentosa (Edwards 1999). The Guadalupe
roundnose minnow (D. nigrotaeniata) is found only in the Colorado and
Guadalupe river basins (Edwards et al. 2004).
Host Records
Commercial or Environmental Importance
D. argentosa is a
sympatric congener of the Devils River minnow (D. diaboli; Garrett et
al. 1992), and as such its status may be aided by current efforts to recover
D. diaboli (Edwards et al. 2004).
The D. argentosa and
D. diaboli sympatric species pair apparently evolved allopatrically
and their current sympatry resulted from the often complex paleohydrology of
the region (Hubbs and Miller 1977; Mayden et al. 1992; Edwards 1999; Edwards
2001).
References
Cantu, N.E.V., and K.O. Winemiller. 1997. Structure and habitat associations
of Devils River fish assemblages. Southwestern Naturalist
42(3):265-278.
Edwards, R.J. 1999. Ecological profiles for selected stream-dwelling Texas
freshwater fishes II. Report to the Texas Water Development Board. 69 pp.
Edwards,
R.J. 2001. Ecological Profiles for selected stream-dwelling Texas freshwater
fishes III. Report to the Texas Water Development Board. 59 pp.
Edwards,
R.J., G.P. Garrett, and N.L. Allan. 2004. Aquifer-dependent fishes of the
Edwards Plateau region. Chapter 13, pp. 253-268 in: Mace, R.E., E.S.
Angle, and W.F. Mullican, III (eds.). Aquifers of the Edwards Plateau. Texas
Water Development Board. 360 pp.
Garrett, G.P., R.J. Edwards, and A.H. Price. 1992. Distribution and status
of the Devils River minnow, Dionda diaboli. The Southwestern
Naturalist 37(3):259-267.
Girard, C.F. 1856. Researches upon the Cyprinoid fishes inhabiting the fresh
waters of the United States of America, west of the Mississippi Valley, from
specimens in the Museum of the Smithsonian Institution. Proceedings of the
Academy of Natural Sciences of Philadelphia 8(5):165-213.
Gold, J.R., Y. Li, M. C. Birkner, and J.D. Jenkin. 1992. Chromosomal nor
karyotypes and genome sizes in Dionda (Osteichthyes: Cyprinidae) from
Texas and New Mexico. The Southwestern Naturalist 37(3): 217-222.
Harrell,
H.L. 1978. Response of the Devil’s River (Texas) fish community to flooding.
Copeia 1978(1):60-68.
Hubbs, C., and G.P. Garrett. 1990. Reestablishment of Cyprinodon eximius
(Cyprinodontidae) and status of Dionda diaboli (Cyprinidae) in the
vicinity of Dolan Creek, Val Verde Co., Texas. The Southwestern Naturalist
35(4):446-448.
Hubbs, C. and
W.H. Brown. 1956. Dionda diaboli (Cyprinidae), a new minnow from
Texas." The Southwestern Naturalist 1(2): 69-77.
Hubbs, C.L., and R.R. Miller. 1977. Six
distinctive cyprinid fish species referred to Dionda inhabiting
segments of the Tampico Embayment drainage of Mexico. Trans. San Diego Soc.
Nat. Hist. 18(17):265-335.
Mayden, R.L.,
R.M. Matson, and D.M. Hillis. 1992. Speciation in the North American genus
Dionda (Teleostei: Cypriniformes). Pp. 710-746 In: Mayden, R.L.
(ed.), Systematics, Historical Ecology, and North American freshwater
fishes. Stanford Univ. Press, Palo Alto, California. 969 pp.
Robinson, D.T. 1959. The Ichthyofauna of the
lower Rio Grande, Texas and Mexico. Copeia 1959(3):253-256.
Scharpf, C. 2005. Annotated checklist of North American freshwater fishes,
including subspecies and undescribed forms, Part 1: Petromyzontidae through
Cyprinidae. American Currents, Special Publication 31(4):1-44.
Schonhuth,
S., I. Doadrio, O. Dominguez-Donminguez, D.M. Hillis, and R.L. Mayden. 2008.
Molecular evolution of southern North American cyprinidae (Actinopterygii),
with the description of the new genus Tampichthys from central Mexico.
Molecular Phylogenetics and Evolution 47(2008):729-756.
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