Reproductive Ecology and Early Life History of a Lacustrine Sculpin, Cottus extensus (Teleostei, Cottidae)
Environmental Biology of Fishes
Using a variety of sampling techniques and observations we describe aspects of the reproductive ecology and early life-history of Bear Lake sculpin, Cottus extensus, a species endemic to Bear Lake, Utah-Idaho. Adult sculpin spawned in shallow water (0.5–6.0 m depths) in cavities beneath large cobbles and boulders. During 1993, egg mass densities were highest (> 4.0 m2) at 1.0–2.0 m depths. Electivity indices verified substrate selection and also indicated an avoidance of s and- and gravel-embedded materials. During years of low water elevation, suitable spawning substrates were restricted to one or two limited areas of the lake and comprised < 0.004% of the total benthic area. Disturbance from turbulence, as would be produced by storm-induced waves, appeared to initiate hatching. After hatching, embryos passed through a pelagic interval that lasted for approximately one week. Laboratory experiments confirmed the short duration of this surface-swimming behavior. The pelagic behavior of free embryos appears to aid in dispersal of fish via currents from limited spawning habitats to areas throughout the 282 km2 lake.
Ruzycki, J., W.A. Wurtsbaugh, and Clyde Lay. 1998. Reproductive ecology and early life history of a lacustrine sculpin, Cottus extensus (Teleostei, Cottidae). Environmental Biology of Fishes 53:117-127.