Pelagic-Intermediate Whitefish

description

Description. Shape: Only slightly deep bodied with greatest body depth anterior of dorsal fin. Dorsal profile from the tip of snout to anterior origin of dorsal fin and ventral profile from interorbital area to pelvic fin origin is straight and only rarely is dorsal profile from tip of snout to interorbital area slightly convex. Head moderately short. Mouth moderately long and subtly sub-terminal. Lower jaw moderately wide. Rostral plate equally wide as deep, not strongly pronounced with tip of snout often more pointed than blunt. Eye-socket moderately thick and sickle cell-shaped. Pectoral fin moderately tapered and moderately short. Dorsal fin rather short with anterior unbranched ray of erected dorsal fin mostly 60 - 70 ° angle to body axis and slightly bent posteriorly. Dorsal fin longest anteriorly and progressively shortening posteriorly with outer margin of dorsal fin mostly concave and rarely straight. Caudal peduncle moderately stout with caudal fin moderately forked. Unbranched rays of anal fin moderately bent posteriorly. Anal fin is longest anteriorly and progressively shortening posteriorly with outer margin of anal fin mostly concave and only rarely straight. Meristic

A taxonomic revision of ten whitefish species from the lakes Lucerne, Sarnen, Sempach and Zug, Switzerland, with descriptions of seven new species (Teleostei, Coregonidae)

diagnosis

Diagnosis. Coregonus suspensus is a medium-sized whitefish (standard length at 3 years of age: range = 266 - 315 mm, mean = 289 mm) with weak pigmentation of the pectoral fin and moderate pigmentation of all other fins and body; greenish blue colour on the flanks above the lateral line; none to a few pigmented small dots on the scales on the flanks; tip of the snout pointy; triangular eye socket; many and moderately long gill rakers (longest gill raker: 13.2 - 16.4 % HL; total gill rakers number = 33 - 37).

A taxonomic revision of ten whitefish species from the lakes Lucerne, Sarnen, Sempach and Zug, Switzerland, with descriptions of seven new species (Teleostei, Coregonidae)

distribution

Distribution and notes on biology. Coregonus suspensus occurs in all basins of Lake Lucerne (Fig. 2) except possibly in Lake Alpnach. It has been caught during the spawning season in all basins except for Lake Alpnach, where no nets were set by Hudson et al. (2016). There is no isotopic or stomach content data available for C. suspensus to infer the prey spectrum of this species. Coregonus suspensus is a medium-sized whitefish species and the size (i. e., standard length) at 3 years of age of C. suspensus is smaller than that of C. litoralis, considerably larger than that of C. muelleri and almost equal to that of C. intermundia (Suppl. material 1: table S 3). We cannot compare its size to C. nobilis since only older individuals of the latter species have been caught (Hudson et al. 2016). Coregonus suspensus shows genetic ancestry contributions from whitefish of Lake Constance, besides its Lake Lucerne ancestry (Hudson et al. 2011, 2016). We therefore also compared it to the four described species from Lake Constance, namely C. wartmanni Bloch, 1784, C. macrophthalmus Nuesslin, 1882, C. arenicolus Kottelat, 1997, and the extinct C. gutturosus Gmelin, 1818. Early indications that C.

A taxonomic revision of ten whitefish species from the lakes Lucerne, Sarnen, Sempach and Zug, Switzerland, with descriptions of seven new species (Teleostei, Coregonidae)

etymology

Etymology. The specific name suspensus in Latin means being ' suspended' or ' levitating'. The name refers to the fact that this species has only been caught during the spawning season in the pelagic water column. An adjective.

A taxonomic revision of ten whitefish species from the lakes Lucerne, Sarnen, Sempach and Zug, Switzerland, with descriptions of seven new species (Teleostei, Coregonidae)