The taxonomy of roaches inhabiting northern Italy, the Western Balkans and southern Greece has not been definitively resolved.

At the generic level, they were included in the genus Rutilus prior to the mid-2010s, before being transferred to the resurrected genus Leucos based on a series of molecular and morphological characters (Bianco and Ketmaier 2014).

However, a number of authors have opted against support of this split, and there is a further lack of consensus regarding the validity of nominal taxa inhabiting the Western Balkans. Subpopulations occurring in this region are either treated as distinct, locally-endemic Rutilus species, i.e., R. basak from the Neretva River system, R. albus from the Lake Skadar basin, R. ohridanus from Lake Ohrid and R. prepsensis from the Prespa Lakes basin (Marić 2010, 2019, Perea et al. 2010, Milošević et al. 2011, Tsoumani et al. 2014, Barbieri et al. 2015, Tutman et al. 2018, Ćaleta et al. 2015, 2019, Freyhof et al. 2020), or lumped together under Leucos basak (Bianco and Ketmaier 2014, Pietrock et al. 2022).

In addition, molecular analyses have demonstrated a close relationship between the Skadar, Ohrid and Prespa subpopulations, and that this subgroup is somewhat divergent from the Neretva River subpopulation (Geiger et al. 2014, Petrosino et al. 2022).

Global and European regional assessment: Endangered (EN)
EU 27 regional assessment: Not Recorded

The White Roach has a restricted range (extent of occurrence (EOO) c. 981 km²), which meets the threshold for the Endangered category under Criterion B1 (EOO < 5,000 km²). It is present at three locations where the extent and quality of habitat are estimated to be declining.

This species is therefore assessed as Endangered under Criterion B (B1ab(iii)).

This species is endemic to the Lake Skadar (sq. Liqeni i Shkodrës; cnr. Skadarsko jezero) basin in Albania and Montenegro, including the Crnojevića River and the lowermost reaches of the Morača River.

Records from the Zeta River, the principal tributary of the Morača, have not been confirmed during recent field surveys.

This species' current population size and trend have not been quantified. It is generally considered to be of low abundance compared with most other native fish species inhabiting Lake Skadar, including the sympatric and congeneric Dalmatian Roach (Leucos basak). There is evidence to suggest that it might be more abundant in the western part of the lake.

Lake Skadar is the most extensive freshwater wetland in the Balkan region, with a surface area that seasonally fluctuates between c. 370 km² and c. 530 km². It is situated in a tectonic karstic cryptodepression and is rather shallow, with an average depth of c. 5 metres and maximum depth of c. 60 metres. The lake is fed by numerous sub-lacustrine karstic springs which are distributed around its periphery, and a series of affluent rivers of which the largest is the Morača. It drains to the Adriatic Sea via the short Bojana (sq. Bunë) River, which also receives water from the Drin (sq. Drini) River and thus connects the system to Lake Ohrid (sq. Liqeni i Ohrit). The precise origin of the lake remains unclear to an extent, but it is understood to have comprised a much larger wetland until c. 1,200 years ago.

This species is most abundant in the lake itself, and during the winter aggregates in areas influenced by sub-lacustrine springs, where the water temperature remains relatively constant throughout the year.

It is a generalist omnivore feeding on a range of algae, plankton and small invertebrates.

The maximum recorded lifespan is c. 6 years and sexual maturity is attained at age 2+. The annual reproductive period extends from late winter to spring, and thus begins earlier than in Dalmatian Roach.

An observed decline in the abundance of native fishes in Lake Skadar since the mid-20^th century has been attributed to a series of factors. In particular, the construction of large hydropower dams on the Drin River has interfered with seasonal fluctuations in the lake's water level and reduced the extent of spawning and nursery habitat. Future plans include the installation of several dams on the inflowing Morača River, which supplies c. 62% of the lake's water. Furthermore, the lower Morača is polluted due to discharge of agricultural, domestic and industrial contaminants, the majority of which originate from Nikšić Polje, the Bjelopavlići Valley and city of Podgorica. The lake has thus become increasingly eutrophic since the 1970s, and this process has driven structural changes in the resident planktonic and zoobenthic communities. The development of tourist facilities, increased boat traffic, and ongoing capture and pollution of karstic springs are also of concern. Plastics and other solid wastes are regularly washed into the lake because effective landfill sites are limited or do not meet modern standards.

A number of non-native fish species have been introduced, including Goldfish (Carassius auratus), Common Carp (Cyprinus domestic strain), Grass Carp (Ctenopharyngodon idella), Eurasian Tench (Tinca tinca), Eurasian Perch (Perca fluviatilis), Eurasian Pikeperch (Sander lucioperca), Northern Pike (Esox lucius), Pumpkinseed (Lepomis gibbosus), Topmouth Gudgeon (Pseudorasbora parva), Eastern Mosquitofish (Gambusia holbrooki), Brown Bullhead (Ameiurus nebulosus) and Rainbow Trout (Oncorhynchus mykiss). All of these taxa are considered to be invasive throughout the Mediterranean region, and can exert detrimental pressures on native freshwater fauna through increased competition, predation, habitat degradation, or transmission of pathogens.

Overfishing may constitute an additional threat, but this has not been extensively-studied.

This species comprises a relatively minor component of the Lake Skadar commercial fishery. It is typically landed as bycatch by fishers targeting Skadar Bleak (Alburnus scoranza) during the winter, when both species aggregate at known sites (see 'Habitats and Ecology'). It is not typically exported, but is regarded as a delicacy by local communities.

This species is listed in Appendix III of the Bern Convention (as Rutilus rubilio).

No conservation management actions are in place, but the Montenegrin part of Lake Skadar was declared a National Park in 1983 and designated a Ramsar Wetland of International Importance (site no. 784) in 1995, while the Albanian portion was nationally-protected and added to the Ramsar Convention in 2006 (site no. 1598).

It is strongly recommended that clarification of this species' taxonomic status is treated as a research priority, while a deeper understanding of its present distribution, abundance, population dynamics, life history and response to the ongoing threats would likely prove beneficial in the design of any structured management plan.