Fish species exhibit a wide range of adaptations and forms, some of which arise from natural processes, while others are a result of human intervention. Among these diverse aquatic inhabitants, certain unique types emerge when two distinct species interbreed, creating a hybrid. These crosses often possess a blend of characteristics from their parent species, leading to novel traits and ecological roles.
Hybrid Origins
A splake is a hybrid fish, specifically a cross between a male brook trout (Salvelinus fontinalis) and a female lake trout (Salvelinus namaycush). Both parent species belong to the Salvelinus genus, which includes char, allowing for their successful interbreeding. While natural hybridization between these two species is extremely rare due to differences in spawning habits and preferred habitats, it can occasionally occur in areas where their ranges overlap. The vast majority of splake are produced artificially in fish hatcheries through controlled breeding programs.
Hatchery production involves fertilizing lake trout eggs with brook trout milt. This artificial propagation allows for the consistent creation of splake in significant numbers for various management purposes. The genetic combination results in offspring inheriting traits from both its cold-water adapted parents. This hybrid vigor can lead to characteristics that are advantageous in specific environments.
Identifying Features
Splake exhibit physical characteristics that are intermediate between their two parent species, making their identification a blend of familiar traits. Their body shape often resembles that of a brook trout, being more streamlined than the deeper-bodied lake trout. Coloration can vary but includes a mix of the dark, mottled patterns (vermiculations) found on brook trout and the lighter spots characteristic of lake trout. These spots are often pale yellow or cream-colored and are present on a darker background.
A distinguishing feature lies in their tail fin, which is forked, though less deeply than the prominent fork of a pure lake trout. This intermediate tail shape provides a visual cue for differentiation from the square or slightly emarginate tail of a brook trout. Splake also possess the white leading edges on their lower fins, similar to brook trout, but may have a more silvery sheen on their flanks, reflecting the lake trout influence.
Purpose and Habitat
Splake were initially developed to combine the desirable traits of both brook and lake trout, particularly for sport fishing and fisheries management. They are known for their relatively fast growth rate and aggressive feeding habits, which make them a popular target for anglers. Their hardiness allows them to tolerate a wider range of environmental conditions than either parent species alone.
These hybrids are primarily found in cold, deep lakes and ponds, often stocked in environments mimicking their parent species’ typical habitats. While lake trout prefer deeper, colder waters, and brook trout inhabit shallower streams and lakes, splake can utilize a broader vertical range. They may occupy deeper waters during warmer periods but also venture into shallower areas during cooler seasons, reflecting their mixed lineage. Their distribution is largely dictated by stocking programs in various regions.