The number of salmonid taxa within some genera (e.g. Salmo, Salvelinus, and Coregonus) listed in various taxonomic databases (e.g. Fishbase or Eschmeyer's Catalog of Fishes) has increased very rapidly over the past 15-20 years. Many of these taxa are not widely accepted across the international community and are associated with very sparse data, leading to significant difficulty in accurately carrying out Red List assessments. The SSG strongly recommends a rigorous evaluation of the validity of these species designations, which can have real implications where legal protection is reflected by the use of these binomial taxonomic names.

The systematics of Eurasian ciscoes and whitefishes (Coregonus spp.) has been the subject of considerable debate since the turn of the 21^st century, with little indication of a definitive outcome.

It is widely accepted that non-anadromous members of this group have repeatedly undergone adaptive radiations in boreal, subarctic and perialpine lakes (Douglas et al. 1999, Østbye et al. 2005, Kahilainen and Østbye 2006, Harrod et al. 2010, Hudson et al. 2011).

Subpopulations inhabiting these systems largely diversified in the wake of the most recent glacial period 10,000-15,000 years ago. They are typified by parallel patterns of divergence in traits associated with foraging (i.e., gill raker counts, benthic vs. pelagic feeding ecology), physiology (i.e., growth rate, habitat depth partitioning) and reproductive ecology (i.e., reproductive timing and spawning habitat).

Up to six different sympatric forms sometimes referred to as “morphs”, "ecomorphs" or "ecotypes" have been recorded in perialpine lakes, and these radiations might be even more diverse in some large systems of northeastern Europe (Præbel et al. 2013, Doenz et al. 2018, Bitz‐Thorsen et al. 2020, Öhlund et al. 2020).

However, there exist significant differences in opinion regarding the taxonomic status of these forms.

In Northern Europe, including the United Kingdom, the majority of subpopulations are usually regarded as belonging to two widely-distributed species; Coregonus albula (ciscoes) and C. lavaretus (whitefishes), with the latter also frequently referred to as the "Coregonus lavaretus species complex” (Etheridge et al. 2012, Wanke et al. 2017, Häkli et al. 2018, Crotti et al. 2020). Within this comparatively uniform taxonomic concept, the catch-all English vernacular name “Vendace” is typically used for C. albula while "Common Whitefish" or "European Whitefish" are applied to C. lavaretus. Irish subpopulations are included within the pan-Arctic Coregonus autumnalis (Arctic Cisco).

In contrast, researchers and fisheries authorities based in Central Europe have tended to treat the different forms as distinct taxa, leading to the recognition of more than 60 species across the European region (Kottelat and Freyhof 2007, Selz et al. 2020, De-Kayne et al. 2022, Selz and Seehausen 2023). Under this diverse taxonomic concept, the name “Vendace” is restricted to its original usage for the United Kingdom endemic Coregonus vandesius and the native range of C. lavaretus is limited to its type locality of Lake Bourget in France. Irish subpopulations are regarded to comprise the endemic species C. pollan.

In the absence of a region-wide consensus, the Red List continues to follow the taxonomy provided by Fricke et al. (2024).

The humpback whitefish species might be in decline at the local scale within some parts of its range, but it remains widespread and its global population size is extremely large. It is therefore assessed as Least Concern.

This species is native to the Arctic and northeastern Bering basins, where it enters rivers along the coastlines of northern Eurasia, the United States (Alaska) and northwestern Canada.

It occurs in rivers draining into the Arctic Ocean from Finland to northeastern Russia, with its range extending eastwards from the Barents Sea to the Chukchi Peninsula.

In North America, its range extends from the Copper River system in Alaska (United States) to the Anderson River in the Northwest Territories (Canada).

Little information is available, but there is anecdotal evidence to suggest the species is declining slowly in some parts of its range.

This species is common in lakes and also occurs in large rivers and brackish estuaries. Both amphidromous and potamodromous individuals can co-occur within the same subpopulation, and spawning sometimes takes place under ice. The species' lifespan can exceed 25 years.

Some North American subpopulations are known to have crashed due to over-harvesting. All members of the family Coregonidae are considered to be vulnerable to the effects of altered temperature and flow regimes driven by climate change.

An important species in subsistence fisheries over much of its range, where it is primarily used for human and animal consumption.

This species is not officially protected, but overharvesting led to the closing of a spear fishery on the Chatanika River, Alaska, during the 1990s. This population has subsequently recovered to an extent and the fishery was reopened with restrictions in 2007.