In some published literature, this species is referred to as a subpopulation or subspecies of the European Cisco (Coregonus albula).

Whitefish subpopulations occupying lakes Stora Hålsjön (Viskan River drainage), Åsunden and Fegen (Ätran River drainage) in Sweden, lakes Änättijärvi, Kostonjärvi, Kokkamo, Pirttijärvi, Suomunjärvi, Sokojärvi, Kajoonjärvi, Luovijärvi and Siikajärvi in Finland, and Lake Tolvajärvi and others in the Republic of Karelia, Russian Federation, were previously considered to be conspecific with the Ören Cisco (e.g., Kottelat and Freyhof 2007).

With the exception of Lake Fegen, all of these subpopulations were extirpated during the 20^th century, and they may together have represented several distinct species.

At the regional scale, the systematics of European 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, all except a handful of Irish 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.

Conversely, 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.

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

The Ören Whitefish has not been observed in the wild since the mid-20^th century, and no ex situ subpopulations exist. This species is therefore assessed as Extinct.

This species was endemic to Lake Ören in the Motala ström River drainage, southern Sweden.

The species became extinct during the mid-20^th century.

This spring-spawning species inhabited deeper parts of the lake and the annual reproductive period extended from late April to early May. Its diet comprised zooplankton.

This species' decline has been attributed to the introduction of non-native predatory fish species such as Eurasian Pikeperch (Sander lucioperca) and pollution from acid rain.

This species was not used or traded.