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COSEWIC Assessment and Update Status Report on the Carmine Shiner in Canada

Update
COSEWIC Status Report
on the
Carmine Shiner
Notropis percobromus
in Canada
2006

Species Information

The taxon was first reviewed by COSEWIC as rosyface shiner (Notropis rubellus) (Houston 1996), but the Manitoba populations are now believed to be the carmine shiner (N. percobromus) (Wood et al. 2002; Stewart and Watkinson 2004; Nelson et al. 2004). The initial review by Houston (1996) summarized knowledge of both shiners, without differentiating between them. This update addresses only the carmine shiner.

Name and Classification

Class:
Actinopterygii
Order:
Cypriniformes
Family:
Cyprinidae
Genus:
Notropis
Species*:
Notropis percobromus (Cope, 1871)
Common name:
English* -- carmine shiner
French -- tête carminée

*Nelson et al. (2004).

The carmine shiner is a small minnow (F. Cyprinidae) of the genus Notropis, the second largest genus of freshwater fishes in North America. Many species in this genus are difficult to distinguish from one another and phylogenetic relationships1 among them are largely unresolved (Dowling and Brown 1989). Recent allozyme2 studies support the existence of at least five species that had hitherto been recognized only as “rosyface shiners”, including the rosyface shiner, highland shiner (N. micropteryx), rocky shiner (N. suttkusi), carmine shiner, and a species that has not yet been described (Wood et al. 2002).

Stewart and Watkinson (2004) accepted the carmine shiner as the identity of the Manitoba population(s) on the basis of the biogeographic information in Wood et al. (2002) and in conformity with Nelson et al. (2004). Ongoing morphometric (K.W. Stewart and D. Watkinson) and genetic studies (DNA; C. Wilson) have confirmed that Manitoba representatives of this “species complex” are carmine shiners, and that rosyface and carmine shiners are distinct species (W. Franzin, pers. comm. 2005).


Morphological Description

Carmine shiners are slender, elongate minnows that can be distinguished from other minnows in Manitoba by the following features: 1) the origin of the dorsal fin is located behind a line drawn vertically from the insertion of the pelvic fins, 2) absence of a fleshy keel on the abdomen and of a strongly decurved lateral line, and 3) a narrowly conical snout that is equal in length, or nearly so, to their eye diameter, 4) 5-7 short gill rakers on the lower limb of the first gill arch, 5) the longest being about as long as the width of its base, and 6) 4 slender, hooked, main row pharyngeal teeth (Stewart and Watkinson 2004; K.W. Stewart, pers. comm. 2005) (Figure 1). The last four characters distinguish the carmine shiner from the emerald shiner (N. atherinoides), with which it is often confused. The emerald shiner has a more blunt, rounded snout, usually only about 3/4 the length of the eye diameter; 8-12 gill rakers on the lower limb of the first arch, the length of longest being twice the width of its base; and four stouter, and only slightly hooked, pharyngeal teeth in the main row on each side (K.W. Stewart, pers. comm. 2005).


Figure 1: Carmine Shiner from the Whitemouth River Watershed in Manitoba

Figure 1: Carmine shiner from the Whitemouth River watershed in Manitoba.

Photo courtesy of D. Watkinson, DFO, Winnipeg.

Outside of the breeding season, carmine shiners are olive green dorsally, silvery on the sides and silvery white on the belly (Scott and Crossman 1973). They have black pigment outlining the scale pockets dorsally, and freshly caught adult specimens often retain pinkish or rosy pigment on the opercula and cheek, which becomes more vivid and extensive during spawning. Fins are transparent. Breeding males develop fine, sandpaper-like nuptial tubercles on the head, on some predorsal scales, and on the upper surface of the pectoral fin rays.

Full development of spawning colour in the carmine shiner is ephemeral, and the colours also fade quickly after death and preservation. Males and females are both brilliantly marked when they are actively spawning. The following description is based on the spawning female in the photograph of Figure 2. Spawning fish of both sexes are olive dorsally and silvery laterally, with reddish colour on the snout, brilliant crimson on the upper portions of the operculum and the cheek, along all of the pectoral girdle and sides around the base of the pectoral fins, the lateral line back to the anal fin, and the bases of the pectoral, pelvic and caudal fins.


Figure 2: Spawning Female Carmine Shiner Collected 7 July 2005 from Below Old Pinawa Dam, Pinawa Channel, Winnipeg River, Manitoba

Figure 2: Spawning female carmine shiner collected 7 July 2005 from below Old Pinawa Dam, Pinawa Channel, Winnipeg River, Manitoba.

Collection and photo by D.A. Watkinson.


Genetic Description

The phylogeny of the rosyface shiner species complex, which includes the carmine shiner, is unresolved. Mayden and Matson (1988) and Dowling and Brown (1989) argued, on the basis of allozyme and mitochondrial DNA variation, respectively, for monophyly of the N. rubellus species group. Woods et al. (2002), who studied the population genetics and phylogenetics of 37 presumptive gene loci in 33 populations throughout the range of the N. rubellus species complex, disagreed. They still recognized a monophyletic N. rubellus species complex but analysis of their data suggested that the taxonomy then employed for N. rubellus did not reflect the patterns of genetic divergence, cladogenesis and phylogenetic affinity within the species group, or between members of this group and other closely related species. Instead, it supported the existence of at least five species that had hitherto been recognized under N. rubellus, including a species that has not yet been described, recently described N. suttkusi (rocky shiner), and three allopatrically distributed species. The latter include N. rubellus (rosyface shiner), N. micropteryx (highland shiner), and N. percobromus (carmine shiner). 

Ongoing studies have confirmed that the carmine and rosyface shiners are separate taxa, as is the emerald shiner, based on both mitochondrial (ATPase 6 and 8 genes) and nuclear (rRNA ITS-1) DNA sequences (C. Wilson, pers. comm. 2005). Research is continuing to identify sequence differences that can be easily detected with restriction enzymes. These studies show that the fish in Manitoba are carmine shiners, like those to the south, and not rosyface shiners like those in eastern Canada.


Designatable Units

Populations of carmine shiner described herein represent the only known occurrence of this taxon in Canada, they occupy a single ecoregion as recognized by COSEWIC, and there is no evidence of relevant differentiation below the species level. Thus, there are no designatable units within this species in Canada.




Footnotes

1 Phylogenetic relationships describe the evolutionary or genealogical history of species relative to one another.
2 Allozymes are forms of an enzyme that differ in their chemistry.