Common nase | European Tracking Network

Common nase

Chondrostoma nasus

Species description and status: Common nase is a potamodromous widespread reophilic cyprinid species, inhabiting large to medium sized and moderate to fast-flowing rivers with rock or gravel bottoms (Juchno et al. 2019). It is distributed in the Black Sea drainage (Danube, Dniestr, South Bug and Dniepr and their tributaries), southern Baltic (Nieman, Odra, Vistula) and southern North Seas drainage (westward to Meuse). Later it was introduced as well to Rhône, Loire, Hérault, Seine (France) and Soča (Italy, Slovenia) drainages.

The common nase is a long-lived species (up to 20 years) that matures relatively late (3-7 years; Lepič et al. 2019) and can grow 20-40 cm (maximum 63 cm; Povž et al. 2015). It can migrate for 200 km and more to spawning and feeding habitats upstream or downstream (Povž et al. 2015). There is not much information on the species behaviour, even though it is quite numerous and can be easily seen grazing on benthic algae on a light-flooded, shallow habitats, using a characteristic horny layer on the lower lip (Zingraff-Hamed et al. 2018). It spawns in big schools on shallow gravel bed (up to 0,5 m; Povž et al. 2015) with relatively strong current and mean daily temperature from 7,5-15,5°C (Ovidio et al. 2008). During longer migrations, adults form singe-species shoals, while juveniles and immature fish form multiple-species schools (Ovidio et al. 2008). Males arrive to the spawning grounds weeks earlier than females and compete among each other, showing territorial behavior (Ahnelt et al. 1994). Outside the spawning season, they are non-territorial and aggregate at the most favorable habitats within the river (Huber & Kirchhofer 1998).

Populations of nase were assessed in 1996 at the IUCN Red List of Threatened Species as Lower risk/Least Concern. The species was reassessed in 2008 and evaluated as Least Concern with unknown population trend (Freyhof 2011). Reasons for decline in their populations can be found in construction of dams for hydropower plant, artificialization of the river banks, changes in hydrobiological regimes, changes in riverbed morphology at spawning times, persisting water pollution and reduction in food resources due to the eutrophication and change of algal periphyton composition (Peňáz 1996; Zbinden & Maier 1996; Ovidio et al. 2008). For nase spawning grounds in Switzerland, Zbinden & Maier (1996) stated that in the past, there used to be spawning schools, made of a few thousand individuals, sometimes up to 10 000, but after 1993 substantially smaller schools were recorded, often less than 50 individuals. Growth of the early onthogenetic stages cannot be fully completed in regulated rivers, which makes the common nase highy sensitive species, thus a good indicator for structural conditions of the river (Peňáz 1996; Zbinden & Maier 1996).

Figure 1. Map of extant (purple) and extant & introduced (orange) distribution of the common nase.  

(Kottelat, M. & Freyhof, J. (2008) 2013. Chondrostoma nasus. The IUCN Red List of Threatened Species. Version 2020-2)

 

Knowledge gaps: Ahnelt et al. (1994) noticed different behaviour among Danube populations when migrating to spawning grounds, which should be further assessed. There is not much known on the effects of minimum flow conditions on the spawning ecology of the nase (Ovidio et al. 2008). There could be more research done on the species-specific biological characteristics (such as autoecological requirements, life history traits, feeding biology, behavioural ecology) that make C. nasus so vulnerable to environmental, man-induced stress (Peňáz 1996).  Translocation programmes still have gaps of knowledge on the mechanisms behind immediate behaviour responses, therefore the success rates of such actions are still largely unknown (Ovidio et al. 2016). Determining the most efficient measures to ensure long term conservation of C. nasus and its populations is still needed (Peňáz 1996).

Regions of interestBlack, southern Baltic and southern North Seas Basins – ecological information and differences in behaviour of different nase population in these ecologically diverse environments is needed.

Telemetry ToolsRadio telemetry was used on the nase for studying habitat use (Huber & Kirchhofer 1998), movement patterns (Ovidio et al. 2008) and evaluating success of translocation programmes (Ovidio et al. 2016).

BenefitsGathered data from tagging will provide us additional information on the continuity of rivers and the functionality of different fish passages. Radio telemetry can be a useful tool for determining the best practices and evaluating the success rates of future translocation programmes. With better knowledge about the population areal (on a local scale) and their genetic structure, sustainable conservation and angling stocking actions can take place where populations have already decreased or new revitalized river stretches can be repopulated with nase.

ContactsPolona Pengal (polona.pengal@ozivimo.si)

 

References:

Ahnelt, H. & Keckeis H. (1994). Breeding tubercles and spawning behavior in Chondrostoma nasus (Teleostei: Cyprinidae): a correlation? Ichthyological Exploration of Freshwaters 5(4), 321-330.

Freyhof, J. (2011). Chondrostoma nasus (errata version published in 2016). The IUCN Red List of Threatened Species 2011

Huber, M. & Kirchhofer, A. (1998). Radio telemetry as a tool to study habitat use of nase (Chondrostoma nasus L.) in medium sized rivers. Hydrobiologia 372, 309-319.

Lepič, P., Blecha, M. & Kozák P. (2019). Intensive Winter Culture of Chondrostoma nasus (Linnaeus, 1758) and Vimba vimba (Linnaeus, 1758) for Spring Restocking. Turkish Journal of Fisheries and Aquatic Sciences 20(2), 97-102.

Juchno, D., Jagusztyn, B. & Boron A. (2019). Reproduction biology of common nase Chondrostoma nasus (Pisces, Cyprinidae). Frontiers in Marine Science Conference Abstract: XVI European Congress of Ichthyology. doi: 10.3389/conf.fmars.2019.07.00015.

Peňáz, M. (1996). Chondrostoma nasus - its reproduction strategy and possible reasons for a widely observed population decline - a review. In: Conservation of Endangered Freshwater Fish in Europe. Kirchhofer, A. & Hefti, D. (Eds.), Birkhäuser, Verlag, Basel, Switzerland, pp. 279-285.

Povž, M., Gregori, A. & Gregori, M. (2015). Sladkovodne ribe in piškurji v Sloveniji. Ljubljana, Zavod UMBRA.

Ovidio, M. & Philippart J. C. (2008). Movement patterns and spawning activity of individual nase Chondrostoma nasus (L.) in flow-regulated and weir-fragmented rivers. Journal of Applied Ichthyology 24, 256–262.

Ovidio, M., Hanzen, C., Gennotte, V., Michaux, J., Benitez, J. P. & Dierckx, A. (2016). Is adult translocation a credible way to accelerate the recolonization process of Chondrostoma nasus in a rehabilitated river? Cybium 4(1), 43-49.

Zbinden, S. & Maier, K. J. (1996). Contribution to the knowledge of the distribution and spawning grounds of Chondrostoma nasus (Pisces, Cyprinidae) in Switzerland. In: Conservation of Endangered Freshwater Fish in Europe. Kirchhofer, A. & Hefti, D. (Eds.), Birkhäuser, Verlag, Basel, Switzerland, pp. 287-297.