Molecular analyses have demonstrated that this species is closely-related to the congeners Knipowitschia panizzae and K. radovici, leading to suggestions that they correspond to a single taxon (Geiger et al. 2014, Thacker et al. 2019).

However, K. radovici and K. mrakovcici are exclusively found in freshwater habitats, while K. panizzae is euryhaline, and the three taxa are diagnosable by morphological characters (Kovačić 2005, Miller 2009).

It is therefore possible that they diverged very recently, in which case powerful genetic markers such as microsatellies or next-generation sequencing would be required to detect any genetic variability (Milana et al. 2021).

In the absence of a definitive review, these three taxa continue to be assessed separately for the Red List.

Global and European regional assessment: Endangered (EN)
EU 27 regional assessment: Endangered (EN)

The Norin Goby has a restricted range (extent of occurrence (EOO) c. 536 km², EU 27 member states c. 180 km²), which meets the threshold for Endangered under Criterion B1 (EOO < 5,000 km²). It is present at three (EU 27 member states = two) locations where the extent and quality of habitat are estimated to be declining.

Therefore, this species is assessed as Endangered under Criterion B (B1ab(iii)), both globally and for the EU 27 member states.

This species is endemic to tributaries and wetlands of the lower Neretva River system in Croatia and Bosnia and Herzegovina.

It has been reported from Lake Modro oko and the Norin River on the right bank, and Hutovo Blato wetland on the left bank of the river.

This species' current population size and trend have not been quantified, and the number of subpopulations is unclear.

This small-bodied, benthic species inhabits oligotrophic streams and channels fed largely by karstic freshwater springs.

Juvenile individuals have been collected from shallow margins with dense submerged vegetation, and adults from deeper water. Substrata are composed of gravel, mud or silt, sometimes littered with woody debris.

Its life history has not been studied, but is presumable similar to that of congeners, whereby male individuals exhibit parental care, constructing a nest within a cavity and guarding the eggs until they hatch. The reproductive period extends from spring to summer.

The diet comprises small crustaceans and benthic invertebrates.

Knipowitschia species are short-lived, and the majority of individuals are believed to have a lifespan of no longer than 12-18 months.

This species is threatened by barrier construction, anthropogenic modification of river channels and pollution from agricultural and domestic sources.

In particular, construction of four large hydroelectric dams along the middle section of the Neretva River main stem since the 1950s has altered natural flow and sedimentation regimes and potentially blocked migration routes, fragmented subpopulations, and markedly reduced the extent of habitat for all life stages. The scale of annual flooding in the Hutovo Blato wetland has declined significantly due to reduced discharge of the Neretva and some affluent springs such as Čapljina, which is also exploited for hydropower generation. The southern part of the wetland was partially impounded in 1979, and a proposed plan to divert water from Hutovo Blato for domestic use may further reduce habitat quality. The proposed construction of around 70 additional hydroelectric projects in the upper reaches of the river, plus an ongoing water diversion scheme in the adjacent Trebišnjica River system together represent a plausible future threat to the entire Neretva ecosystem.

The extent and quality of habitat in the lower Neretva area has been further diminished by bank stabilisation, channelisation and other efforts to enhance flood protection or exploit water resources for irrigated agriculture. In the river's delta, only three of its original twelve branches remain and most former marshes and lakes have been reclaimed for agriculture since the 1960s. Diffuse and point source agricultural, domestic and industrial pollution has resulted in eutrophication or discharge of toxic substances at some locations.

In addition, a number of other non-native fish species that are documented to exert negative effects on native ichthyofauna through predation, resource competition or habitat degradation are established within its range, including Pumpkinseed (Lepomis gibbosus), Largemouth Bass (Micropterus salmoides), Eurasian Ruffe (Gymnocephalus cernua), Prussian Carp (Carassius gibelio), Common Carp (Cyprinus domestic strain), Topmouth Gudgeon (Pseudorasbora parva), Brown Bullhead (Ameiurus nebulosus), and Eastern Mosquitofish (Gambusia holbrooki).

The main spring feeding the Norin River is exploited for drinking water, although the site is otherwise in relatively good condition.

This species is not used or traded.

This species is included in Appendix III of the Bern Convention (as Padogobius panizzai).

It is nationally-protected in Croatia, where it is covered by the Nature Protection Act (OG 80/13) and Ordinance on Strictly Protected Taxa (OG 144/13, 73/16). It is currently assessed as Vulnerable for the National Red List of Croatia.

No specific conservation management plan exists, but parts of this species' range are located within protected areas. Among these, Hutovo Blato and the Neretva Delta are included in the Ramsar Convention on Wetlands and a few sites are listed in the European Union's Natura 2000 network. A new, ostensibly more sustainable, management policy was implemented in the Hutovo Blato basin following a European Union-funded LIFE project which ran from 2000-2002.

The proposed hydropower developments in the Neretva and Trebišnjica rivers have been opposed by local communities and several NGOs, leading to the publication of various news articles, reports, research projects and dissemination events, e.g., Neretva Science Week (July 2022).

It is recommended that the Norin Goby's taxonomic status should be resolved as a research priority, in order to facilitate effective management (see 'Taxonomic Notes').