*5.2. Conservation Status*

Compared to *K. pannizae*, *N. canestrinii* distribution is geographically more restricted (Table 3), abundant only in the Northern part of the Adriatic Sea, but it can reach a similar or higher density. In the Venice lagoon, in fact, its annual mean in the saltmarsh creek was found to be 1137 ± 2780 ind/ha (*K. pannizae* was 1374 ± 3167 ind/ha), while it resulted more abundant than *K. panizzae* in other saltmarsh zones, less sheltered but with lower salinity: *N. canestrinii* 239 ± 247 ind/ha compared to *K. pannizae* 58 ± 86 ind/ha [69]. Despite the fact that *N. canestrinii* shows a preference for saltmarsh creeks, it can be found also in more open areas, with biomass one order of magnitude higher than that of *K. pannizae* (*N. canestrinii* 115 ± 159 g/ha compared to *K. pannizae* 11 ± 16 g/ha) [69]. Considering the seasonal distribution, *N. canestrinii* was found to have similar density in both saltmarsh creeks (5.60 ± 15.61 ind/100 m<sup>2</sup> in summer and 3.26 ± 9.81 ind/100 m<sup>2</sup> in winter) and mudflats (3.32 ± 5.94 ind/100 m<sup>2</sup> in summer and 4.87 ± 11.58 ind/100 m<sup>2</sup> in winter) [80].

As an oligohaline species, *N. canestrinii* can be common also in freshwater habitats, where other factors could threat its local population survival. For Trasimeno Lake, for example, it has been hypothesized that the Eurasian copepod *Lernaea cyprinacea* could infest the host, generally belonging to the Gobionellidae family, causing its death [95]. At present, there is no evidence of parasitism on *N. canestrinii* and it is established that in brackish waters this risk is remote because *L. cyprinacea* does not tolerate even low salinity [95].

According to IUCN assessments, the threat level for *N. canestrinii* is least concern and the status is favourable [96]. Its presence is reported in 26 Natura 2000 sites, 20 of which are priority habitats 1150\* (Table 3). The restricted range can determine limited gene flow, reducing the intraspecific genetic biodiversity, but no data are available in the literature describing the di fference among populations. Although not considered to be an endangered species, its distribution and density should be carefully monitored, because it represents a good indicator of the conservation status of coastal lagoon habitats in its structural and morphological complexity (salts, small canals, shallow bottoms, etc.) and is important for nekton community biodiversity.
