Amphorina andra ( Korshunova, Malmberg, Prkić, Petani, Fletcher, Lundin & Martynov, 2020 )

Broms, Fredrik, 2024, Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway, Fauna norvegica 43, pp. 84-109 : 102

publication ID	https://doi.org/10.5324/fn.v43i0.5840
persistent identifier	https://treatment.plazi.org/id/03D0903A-C52F-B808-EF8A-18B90C5DF80A
treatment provided by	Felipe
scientific name	Amphorina andra ( Korshunova, Malmberg, Prkić, Petani, Fletcher, Lundin & Martynov, 2020 )
status

Treatment

Amphorina andra ( Korshunova, Malmberg, Prkić, Petani, Fletcher, Lundin & Martynov, 2020) View in CoL

Figure 5F View Figure 5 /5G/5H

Material examined: Two specimens, KVA, 19 February 2021, FB, NTNU-VM-84496/NUIT-1006-1 ( Figure 5H View Figure 5 ), NTNU-VM-84496/ NUIT-1006-2 ; One specimen, ESU, 29 September 2021, FB, NTNU- VM-84468/NUIT-1032 ( Figure 5G View Figure 5 ) , One specimen, ESU, 08 January 2022, 12 mm, FB, NTNU-VM-84558/NUIT-1102 ; One specimen, UTE, 26 August 2022, FB, photographic record ; Two specimens, UTE, 24 October 2022, 20, 26 mm, FB, NTNU-VM-85702/NUIT-1236 ( Figure 5F View Figure 5 ); NTNU-VM-85672/NUIT-1237 . One specimen, UTE, 24 September 2023, 18 mm, FB, NUIT-1322 .

Localities: ESU, KVA, UTE

Distribution and remarks: Amphorina andra was described as recently as 2020 ( Korshunova et al. 2020b). Records of the species are therefore sparse but include findings north to Trondheimsfjorden ( Moen & Svensen 2020) and Bodø in Nordland ( Lundin et al. 2020). The species occurs in several different colour forms and subdivisions ( Korshunova et al. 2020b). In Tromsø, three different colour forms were observed; a uniformly bright golden yellow form ( Figure 5F View Figure 5 ), a uniformly transparent-white form with a completely pale body and cerata ( Figure 5G View Figure 5 ) and a moderately transparent white form with orange-yellow pigment on the tips of the cerata ( Figure 5H View Figure 5 ). In the literature, a strict water depth differentiation between A. andra and the closely related Amphorina viriola has been described. While A. viriola has been found associated with low salinity above the halocline, A. andra is associated with higher salinity below the halocline ( Korshunova et al. 2020b). In the present study, A. andra was found to be commonly occurring in the Ascophyllum nodosum belt in the intertidal where animals and spawn were occasionally even found emersed above water between tides. The species may thus inhabit more shallow waters than previously known. The present observations are the first records from the Tromsø region and represent a new northerly distribution record for the species.

Amphorina pallida (Alder and Hancock, 1842) Figure 5I View Figure 5 /5J

Material examined: One specimen, EKJ, 12 December 2020, FB, photographic record ( Figure 5I View Figure 5 ) ; One specimen, KVA, 23 October 2021, FB, NTNU-VM-85730/NUIT-1062 ; Three specimens, KVA, 14 November 2021, 9, 8, 7 mm, FB, NTNU-VM-84556/NUIT-1051, NTNU-VM-85668/NUIT-1052, NTNU-VM-84588/NUIT-1053 ; One specimen, THA, 19 December 2021, 7 mm, FB, NTNU-VM-84567/ NUIT-1091 ; One specimen, KVA, 01 February 2022, FB, photographic record ( Figure 5J View Figure 5 ) .

Localities: EKJ, ESU, HIL, KFH, KVA, THA, TVK, UTE

Distribution and remarks: Amphorina pallida has been reported from most of the Norwegian coast ( Evertsen & Bakken 2005; Lundin et al. 2020). The species exists in different colour variations ( Korshunova et al. 2020b). In the present study, two different colour forms were observed. The most common form included specimens with extensive red-brown pigment ( Figure 5I View Figure 5 ). A less frequent form included pale specimens with white pigment on the head and cerata but with none or few small reddish pigment dots on the body ( Figure 5J View Figure 5 ). The species has been described as sparse and occurring mainly on hard bottom at 20-50 m depth ( Moen & Svensen 2020; Lundin et al. 2020). In the present study, A. pallida was, however, found to be common in shallow waters, both at fouling communities and in the intertidal. The species was recorded during all months of the year. The present records are the first records from the Tromsø region.

Eubranchus exiguus (Alder & Hancock, 1848) Figure 5K View Figure 5

Material examined: One specimen, THA, 17 February 2021, FB, photographic record ; One specimen, HIL, 14 November 2023, 4 mm, FB, NUIT-1334 ( Figure 5K View Figure 5 ) .

Localities: HIL, THA

Distribution and remarks: Eubranchus exiguus has previously been reported from most of Norway ( Evertsen & Bakken 2005) and also from the Murman coast in Russia ( Martynov et al. 2006). However, recent revision of the genus demonstrated the existence of a pseudocryptic new species hidden under the name E. exiguus ( Grishina et al. 2022) . The new species, Eubranchus scintillans , was previously considered a colour form of E. exiguus . As both species are found sympatrically in the Barents and the North Seas ( Grishina et al. 2022) earlier published records of E. exiguus may refer to either of the two species and are in need of re-examination to verify identity. Only two specimens of “true” E. exiguus were recorded by this study. The present observations are the first published records of “true” E. exiguus from the Tromsø region. The distributional status of “true” E. exiguus in Norway remains to be investigated.

Eubranchus rupium (Møller, 1842) Figure 5L View Figure 5

Material examined: One specimen, THA, 17 August 2021, 11 mm, FB, photographic record ( Figure 5L View Figure 5 ) ; One specimen, UTE, 17 November 2021, 9, 5 mm, FB, NTNU-VM-84438/NUIT-1016 ; Two specimens, EKJ, 05 May 2022, 12, 11 mm, FB, NTNU-VM-85703/ NUIT-1161, NTNU-VM-85650/NUIT-1162 ; One specimen, HIL, 12 June 2022, 13 mm, FB, NUIT-1179 ; One specimen, TPO, 16 March 2023, 11 mm, FB, NUIT-1274 ; One specimen, EKJ, 29 July 2023, 10.5 mm, FB, NUIT-1305 .

Localities: EKJ, HIH, HIL, SKI, THA, TPO, UTE

Distribution and remarks: Eubranchus rupium was reported as a new species for the Norwegian fauna in 2013 ( Evertsen & Bakken 2013). In Russia, E. rupium has been reported from the Barents and White Sea ( Martynov et al. 2006). Using DNA barcoding Descôteaux and co-workers also recently found E. rupium larvae north of the polar front ( Descôteaux et al. 2021). The present study found E. rupium to be a commonly occurring nudibranch both at fouling communities and in the intertidal. Animals were found all year round, mainly in association with Obelia hydroids growing on Saccharina latissima . Spawning was mainly observed in May – August but was also recorded during October - November. These observations together with recent information on the species in Norway ( Evertsen & Bakken 2013, Bakken et al. 2024a) strongly indicate that the distribution of E. rupium in Norway is much wider than previously known. The records from the present study are however the first known records of E. rupium from the Tromsø region.