In this issue of my blog, I will introduce you to a fish that spends its entire life in an area approximately the size of the interior of your car. They are the model, “stay at home” fish. Meet the slimy sculpin. Perhaps an unfortunate name, as they are not slimy based on my personal experience. Most fish feel smooth to the touch because they produce mucus which protects their bodies and reduces friction with the water. Slimy sculpins also have no scales and no swim bladder. The swim bladder is a gas filled sac that assists in buoyancy. Without this organ fish eventually sink to the bottom unless they are swimming. So, if you deduced from this bit of information that the slimy sculpin lives on the bottom, you would be right! In addition, it really doesn’t swim but hops, supported by larger fan-like fins in the front. In the Petitcodiac River system, most slimy sculpin that I have seen are about 5 to 7 cm in length.
Slimy sculpin (Wikipedia)
The slimy sculpin can be found in the cool well oxygenated tributaries of the Petitcodiac River. They require high quality habitat. Considering this requirement and that they spend their lives in a very confined area, they are ideal as biological monitors of water quality. A reduction in their abundance can signal a decline in their environment. Unlike periodic tests for water quality which only reflect current conditions, the slimy sculpin is affected by conditions over a more prolonged period. Since the slimy sculpin does remain in a very limited area, we know that any change in its abundance or health is due to local exposure and not the result of a return migration from a contaminated site.
Mating season typically commences in April, extending into May. Males at this time have a band of orange on their first dorsal fin which plays a role in attracting females. The males establish a nest usually under a rock or a piece of wood. The female decides whether the male is suitable and if so deposits her adhesive eggs under the rock or log.
Yes, the female is upside down when she deposits her eggs. The male then fertilizes the eggs and defends them for several weeks and might even look after the young for a period of time. As soon as the female lays her eggs, the male chases her away and tries to convince another female to also lay her eggs in the same nest. Nests typically contain the eggs from two to three females.
https://dep.nj.gov/njfw/wp-content/uploads/njfw/Slimy-Sculpin.pdf
The slimy sculpin is a poor swimmer and hence finds itself on the dinner plate of other species of fish as well as birds such as kingfishers. Some fly fishing patterns are actually modelled after this species. Slimy sculpin live for about five years.
Learn to tie the low fat sculpin (above). Not our species but you can see the resemblance. The name is not a typo, I have no idea if they have less fat than other species. https://www.youtube.com/watch?v=UMxMbPgY90s