Shore Whitefish

description

Description. Shape: Generally deep bodied with greatest body depth anterior of the dorsal fin. Dorsal profile from tip of snout to anterior origin of dorsal fin is strongly convex and ventral profile moderately convex from interorbital area to pelvic fin origin. Head short. Mouth short and sub-terminal. Rostral plate pronounced and a bit wider than deep resulting in a slightly rectangular shape. Tip of snout often blunt. Small eye with a thick and sickle cell-shaped eye-socket. Pectoral fin moderately tapered and moderately short. Dorsal fin long with anterior unbranched ray of the erected dorsal fin mostly 60 - 70 ° angle to body axis and slightly bent posteriorly at the end of the ray. Dorsal fin longest anteriorly and progressively shortening posteriorly with the outer margin of dorsal fin straight. Caudal peduncle stout and short with caudal fin moderately forked. Unbranched rays of anal fin slightly bent posteriorly. Anal fin longest anteriorly and progressively shortening posteriorly with the outer margin of anal fin mostly straight and only rarely slightly concave. Meristics: Few and short gill rakers. Colour: Pigmentation of fins and body overall strong in live specimens. P

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 litoralis is a large whitefish (standard length at 3 years of age: range = 325 - 392 mm, mean = 353 mm) with strong pigmentation of all fins and body; greenish blue colour that sometimes has a pale mustard yellow undertone on the flanks above the lateral line; moderate to many pigmented small dots on the scales along the flank and the dorsum; deep bodied (23.4 - 30 % SL, mean = 26.9); blunt snout; short head (19.2 - 20.9 % SL, mean = 19.9); sub-terminal mouth; small eye (eye diameter: 18.2 - 21.4 % HL, mean = 20.2) with a thick and triangular-shaped eye socket; short and stout caudal peduncle (caudal peduncle depth: 7.5 - 8.4 % SL, mean = 8.1; caudal peduncle length: 11.5 - 14.3 % SL, mean = 12.6); few and short gill rakers (longest gill raker: 9.2 - 13.1 % HL, mean = 11; total gill raker number: 24 - 32).

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 litoralis occurs in all basins of Lake Lucerne (Fig. 2). Based on genetic assignments it has been identified to be present in Lake Sarnen (Suppl. material 1: figs S 2, S 3). It is unclear if C. litoralis occurs naturally in Lake Sarnen or has been introduced (this is discussed in more detail in the Suppl. material 1: paragraph 1). Coregonus litoralis feeds predominantly on benthic prey (e. g., chironimid, pisidium) and parts of the year on zooplankton (e. g., bythotrephes, daphnia) (stomach content: Cysat 1661; Birrer and Schweizer 1938; isotopic signature: Selz 2008; Hudson 2011; Ingram et al. 2012). Feeding experiments with individuals of this species and other whitefish species from lakes Thun and Lucerne (Lundsgaard-Hansen et al. 2013; Roesch et al. 2013) suggest - based on the functional properties of the number of gill rakers - that the low-rakered C. litoralis feeds predominantly on benthic prey. Coregonus litoralis has a fast growth rate (Svarvar and Mueller 1982; Mueller et al. 2007) and is a large whitefish species. The size (i. e., standard length) at 3 years of age of C. litoralis is larger than that of C. suspensus and C. in

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 in Latin means ' coming from the shore'. The name refers to the specific spawning habitat of this species, spawning in very shallow water of a few metres close to or directly at the lake shore. 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)