 |
The Peace/Williston Fish and Wildlife Compensation Program (PWFWCP) |
||||
            
   |
Prickly Sculpin
What do they look like? A chunky sculpin with a single chin pore and, in profile, a pointed snout. The lateral line is complete, and the dorsal fins are usually connected for about a third of the first element of the second dorsal fin. The anal fin has 15 to 19 rays with the anterior anal rays scarcely incised. The anal fin base is longer than the head and the palatine teeth are well developed. In breeding males, the entire body is black except for an orange trim on the first dorsal fin. Breeding females retain their normal colour and have noticeably swollen abdomens. Where do they live? Prickly sculpins occur in both flowing and standing waters. In rivers, adults are generally found in quiet water (in deep pools, under cutbanks, or associated with woody debris). In lakes, adults are again associated with cover, especially areas where cobbles or woody debris are interspersed among sandy patches. During the day they remain in, or close to, cover but at night forage in the open. Although adults are commonly observed in littoral areas, baited traps catch them at depths down to at least 100 m. Smaller individuals occupy similar areas but in shallower water. In inland rivers, the young-of-the-year are found in quiet edge sites and are commonly associated with vegetation or small woody debris. What is their life like? In B.C., prickly sculpins spawn in the spring (April to late-June) when water temperatures rise above 6 °C. They continue to spawn until temperatures reach about 16 °C. In March and April there is a pronounced downstream migration of adults into estuaries of short coastal streams. Apparently, inland populations do not perform extensive spawning migrations and, even in short coastal streams, some adults spawn in situ rather than migrating to estuaries. Regardless of where they spawn, males excavate a nesting site - usually under a flat rock or solidly embedded woody debris - and defend the site against intrusions by other males. Once in the nest, the female deposits her eggs on the roof of the nest. The yellow-orange eggs are adhesive. Normally, males spawn with more than one female and the single egg mass commonly contain different coloured eggs. Like most fish, fecundity in prickly sculpins is a function of female body size, and ranges from approximately 300 eggs to over 10,000. Males use their pectoral fins to fan the eggs. They guard the nest until the entire egg mass is hatched, this takes 15-16 days at 12 °C. The transparent larvae are about 5-6 mm in length and are active immediately upon hatching. The transparent larvae remain planktonic for 30-35 days before they transform into small sculpins (about 12 mm in length). Growth in prickly sculpins varies among populations but in their first summer they reach about 30-40 mm by September, and 50-60 mm by the end of their second growing season. Adult size varies among populations but often exceeds 200 mm in total length. Sexual maturity is reached in two or three years and the maximum age recorded in B.C. is 8+ years old. What do they eat? Larval prickly sculpins feed on microplankton, but on transformation they become benthic and their diet shifts towards benthic prey. In lakes, fry feed on both plankton and aquatic insect larvae. In flowing water and lakes, juveniles and adults less than 70 mm long forage primarily on the nymphs and larvae of aquatic insects (especially chironomids, mayflies, and stoneflies). Individuals over 70 mm begin to add fish to their diet, and large adults (over 120 mm long) can be significant predators on salmonid fry.
|
||||
  |
|||||
| A joint initiative of BC Hydro, the BC Ministry of Environment, and Fisheries and Oceans Canada |
