Notropis oblitus, Pinion & Kim & Dolan & Portnoy & Voelker & Conway, 2025

Pinion, Amanda K., Kim, Daemin, Dolan, Elizabeth P., Portnoy, David S., Voelker, Gary & Conway, Kevin W., 2025, ? Revision of Notropis stramineus (Cope, 1865), descriptions of three new species and comments on the monophyly of Miniellus Jordan, 1882 (Pisces: Cypriniformes: Leuciscidae), Vertebrate Zoology 75, pp. 699-755 : 699-755

? Notropis oblitus sp. nov.

Figures 13 C – 13 , 14 , 15 , 16 C , 27 , 28

Holotype.

TCWC 16882.13 , male, 41.2 mm SL. United States of America, Texas: Uvalde County, Frio River at Texas State Highway 127 crossing in Concan , 29°29'44"N 99°42'42"W; 15 May, 2015, Conway, K. W., Kubicek, K. M., and Prestridge, H. L. (Fig. S 16) .

Paratypes.

TCWC 6221.03 , 2, 39–44 mm SL; Kerr: Mo Ranch , 30°03'10"N 099°28'24"W; 30 April, 1985 . – TCWC 6811.01 , 2, 32–50 mm SL; Comal: Guadalupe River on HWY 306, 0.2 miles north of HWY 2673 , 29°51'52"N 098°09'50"W; 16 July, 1983 . – TCWC 174.02 , 22, 28–44 mm SL; Blanco: Blanco River at Blanco , 30°05'52"N 098°24'57"W; 26 November, 1950 . – JFBM 18598 , 8, 21–33 mm SL; Hays: Blanco River, 6 miles W of Kyle (station 18) , 30°00'17"N 097°58'07"W; 14 November, 1955 . – TCWC 16802.06 , 28, 31–38 mm SL; Kerr: Guadalupe River at bridge crossing on FM 1340 , 30°03'08"N 099°27'04"W; 15 May 2015 . – TCWC 15549.06 , 11, 22–42 mm SL; Real: Kent Creek @ 336 , 30°40'09"N 100°32'57"W; 15 October, 2011 . – TCWC 16326.15 , 40, 20–44 mm SL; Uvalde: Nueces River at FM 55 , 29°37'03"N 100°00'33"W; 20 April 2013 . – TCWC 16328.08 , 69, 25–45 mm SL; Bandera: Sabinal River at RM 337 , 29°44'40"N 099°33'10"W; 21 April 2013 . – TCWC 16876.1 , 39, 18–39 mm SL; Uvalde: Frio River , 29°36'23"N 099°44'19"W; 18 January, 2014 .

Diagnosis.

Notropis oblitus sp. nov. is distinguished from all other members of the N. stramineus species group, except N. stramineus , by a relatively large eye (orbit diameter ca. 32 % of HL vs. 26–29 % HL) in combination with a low, rounded head (vs. a relatively steeply sloped head). It is further distinguished from N. stramineus by possessing fewer vertebrae (35 vs. 36–37), and from N. stramineus , N. multicorniculatus sp. nov. and N. missuriensis by a reduction in body pigmentation, with pigment on posterior half of body dorsal to lateral-line scale row reduced, cross-hatch pattern on scales sometimes absent posteriorly (vs. consistently pigmented posteriorly), as well as a lack of pigment ventral to the lateral-line scale row anteriorly, aside from cleithral streak (vs. first few scale rows with cross-hatch pattern ventral to lateral-line scale row in addition to cleithral streak). Notropis oblitus sp. nov. is further distinguished from N. lucifer sp. nov. by the presence of a typically well-developed cleithral streak (vs. cleithral streak absent or very weakly developed), the presence of pigmentation arranged in a cross-hatch pattern in all scale rows dorsal to lateral line (rarely reduced posteriorly) (vs. absent or reduced to sparse pigmentation on 2–3 scale rows dorsal to lateral-line scale row, including anteriorly), by cephalic pigmentation present in similarly-sized melanophores scattered evenly across most regions of the head (vs. restricted in distribution and consisting of a few clusters of melanophores), and by the presence of a peach-yellow pigmentation on the pectoral fins and pectoral-fin base in live males (vs. pectoral fins hyaline, and pectoral-fin base silvery or cream colored in life). Notropis oblitus sp. nov. is further distinguished from N. topeka and N. procne by the absence (vs. presence) of a dark lateral stripe along body side, from N. topeka and N. multicorniculatus sp. nov. by the presence of minute tubercles in reproductively active males (vs. large tubercles in reproductively active males), and further from N. topeka by an approximately even distribution of tubercles across the dorsal and lateral surfaces of the head (vs. densest in dorsal regions, largely absent from the lateral infraorbital, preopercular, opercular, and subopercular regions), and by a larger eye (orbit diameter 32.3 % HL vs. 26.3 % HL). Notropis oblitus sp. nov. is further distinguished from N. chihuahua by the presence of small, evenly distributed melanophores on all regions of the dorsal surface of the head (vs. melanophores restricted to fronto-occipital region, interorbital region, and in internarial, nasal, and rostral region present as irregularly scattered macromelanophores), as well as the presence of cross-hatching on scale rows dorsal to the lateral-line scale row anteriorly (vs. restricted to two to three scale rows ventral to dorsal midline anteriorly).

Description.

Body shape and general appearance as in Figures 27 and 28 . Morphometric and meristic data are listed in Tables 7 . As described for N. stramineus , except for the following. Eye very large, head low and round with rounded, blunt snout. Cephalic tuberculation weakly developed, inconspicuous and not visible without magnification, with small conical tubercles distributed sparsely across regions of head. Tubercles most densely concentrated in lacrimal, orbital, and preopercular regions, with tubercles scattered sparsely across internarial and fronto-occipital regions. Tubercles absent from rostral, opercular and subopercular regions, and in all ventral regions of head. Pectoral-fin tuberculation well developed, with four-five rows of large conical tubercles developed along pectoral-fin rays 1–7, and 1–2 rows of tubercles present on anteriormost margin of first pectoral-fin ray.

Coloration.

Coloration in preservative as in Notropis stramineus except for the following. Body background color in preservative a light yellow to whitish (Fig. 27 ). Melanophores below lateral-line canal sparse anteriorly, largely absent posteriorly until approximately vertical with insertion of anal fin, where melanophores ventral to lateral-line canal create weak, dusky band. Coloration in life silvery, pale, with straw or yellow-colored pigmentation restricted to uppermost part of body side, bluish sheen present but weak (Fig. 28 A ). Chromatophores on dorsal midline creating thick golden streak (Fig. 28 B ). Cleithral streak variable in intensity, often distinct, sometimes weak, in life and in preservation.

Distribution.

Notropis oblitus sp. nov. is distributed throughout several independent Gulf Slope streams in Texas, including the upper reaches of Nueces, San Antonio, and Guadalupe River basins (Fig. 29 ) in the Edwards Plateau ecoregion. It appears to be absent from the Colorado River basin.

Etymology.

The species name oblitus , forgotten, is the perfect participle of the Latin verb “ obliterare ”, to forget. The name alludes to Carl Hubbs’ recognition of the distinctiveness of southern populations of the sand shiner in the form of a third subspecies of Notropis deliciosa ( Girard) 1856 (= Notropis stramineus ), and the subsequent incidental loss of this recognition by other NA ichthyologists; oblitus , the perfect participle of the verb obliterare, also means “ smeared ” or “ blurred ”, a reference to the possible hybrid nature of the external morphological features with that of N. lucifer sp. nov. collected in the Colorado River basin of Texas. An adjective.

Figures

Figure 13. Lateral view of heads of males of each member of Notropis stramineus species group; A Notropis stramineus sensu stricto (Clade 1), ROM 11967, 46.6 mm SL; B N. multicorniculatus sp. nov. (Clade 2), TCWC 15789.07, 43.2 mm SL; C N. oblitus sp. nov. (Clade 3), TCWC 16802.06, 41.2 mm SL; D N. missuriensis (Clade 4), KU 4186, 48.4 mm SL; E N. lucifer sp. nov., Devils River (Clade 5), TCWC 15689.04, 43.2 mm SL; F N. lucifer sp. nov., Col. drainage (Clade 6), TCWC 19721.01, 42.3 mm SL; G Notropis topeka, KU 40725, 46.1 mm SL; H Notropis procne, NCSM 12688, 51.1 mm SL; I Notropis chihuahua, UMMZ 211231, 41.8 mm SL. Scale bars = 2 mm.

Figure 14. Dorsal view of heads of males of each member of Notropis stramineus species group; A Notropis stramineus sensu stricto (Clade 1), ROM 11967, 46.6 mm SL; B N. multicorniculatus sp. nov. (Clade 2), TCWC 15789.07, 43.2 mm SL; C N. oblitus sp. nov. (Clade 3), TCWC 16802.06, 41.2 mm SL; D N. missuriensis (Clade 4), KU 4186, 48.4 mm SL; E N. lucifer sp. nov., Devils River (Clade 5), TCWC 15689.04, 43.2 mm SL; F N. lucifer sp. nov., Col. drainage (Clade 6), TCWC 19721.01, 42.3 mm SL; G Notropis topeka, KU 40725, 46.1 mm SL; H Notropis procne, NCSM 12688, 51.1 mm SL; I Notropis chihuahua, UMMZ 211231, 41.8 mm SL. Scale bars = 2 mm.

Figure 15. Ventral view of heads of males of each member of Notropis stramineus species group; A Notropis stramineus sensu stricto (Clade 1), ROM 11967, 46.6 mm SL; B N. multicorniculatus sp. nov. (Clade 2), TCWC 15789.07, 43.2 mm SL; C N. oblitus sp. nov. (Clade 3), TCWC 16802.06, 41.2 mm SL; D N. missuriensis (Clade 4), KU 4186, 48.4 mm SL; E N. lucifer sp. nov., Devils River (Clade 5), TCWC 15689.04, 43.2 mm SL; F N. lucifer, Col. drainage (Clade 6), TCWC 19721.01, 42.3 mm SL; G Notropis topeka, KU 40725, 46.1 mm SL; H Notropis procne, NCSM 12688, 51.1 mm SL; I Notropis chihuahua, UMMZ 211231, 41.8 mm SL. Scale bars = 2 mm.

Figure 16. Caudal peduncles of males of each member of Notropis stramineus species group; A Notropis stramineus sensu stricto (Clade 1), ROM 11967, 46.6 mm SL; B N. multicorniculatus sp. nov. (Clade 2), TCWC 15789.07, 43.2 mm SL; C N. oblitus sp. nov. (Clade 3), TCWC 16802.06, 41.2 mm SL; D N. missuriensis (Clade 4), KU 4186, 48.4 mm SL; E N. lucifer sp. nov., Devils River (Clade 5), TCWC 15689.04, 43.2 mm SL; F N. lucifer sp. nov., Col. drainage (Clade 6), TCWC 19721.01, 42.3 mm SL; G Notropis topeka, KU 40725, 46.1 mm SL; H Notropis procne, NCSM 12688, 51.1 mm SL; I Notropis chihuahua, UMMZ 211231, 41.8 mm SL. Scale bars = 2 mm.

Figure 27. Notropis oblitus sp. nov., USA, Texas: Uvalde County, Frio River; A TCWC 16882.13, holotype, male, 41.2 mm SL; B TCWC 16882.06, paratype, female, 43.1 mm SL. Scale bars = 5 mm.

Figure 28. Notropis oblitus sp. nov., TCWC 20319.09, male, photographed alive, in two views; USA, Texas, Bandera County, Sabinal River. A lateral view; B dorsal view. Scale bar = 5 mm.

Figure 29. Map of southern Texas and Northern Mexico, depicting distribution of samples of Notropis oblitus sp. nov. and N. lucifer sp. nov. used in 3 - gene dataset. Type localities of each new species indicated by a star.