Flabellinidae (Bergh, 1889)

Broms, Fredrik, 2024, Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway, Fauna norvegica 43, pp. 84-109 : 100

Family Flabellinidae (Bergh, 1889)

Carronella (Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, Saito, Lundin, Schrödl & Picton, 2017) Carronella sp.

Figure 5B

Material examined: One specimen, HIL, 09 January 2021, FB, photographic record ; One specimen, HIL, 27 November 2021, 17 mm, FB, NTNU-VM-84536/NUIT-1070 ; Two specimens, HIL, 09 January 2022, 27, 20 mm, FB, NUIT-1114, NTNU-VM-84537/NUIT-1115 ; One specimen, THA, 08 February 2022, 35 mm, FB, NTNU-VM-84466/ NUIT-1121 ( Figure 5B ) ; One specimen, HIL, 12 February 2022, 25 mm, FB, NTNU-VM-84507/NUIT-1129 ; One specimen, HIL, 03 December 2022, 34 mm, FB, NUIT-1256 .

Localities: HIL, THA, TPO

Distribution and remarks: There are two known species within the genus Carronella ; Carronella pellucida Alder and Hancock, 1843 and Carronella enne Korshunova et al. 2017 . It is currently not possible to identify the two Carronella species based on external morphology ( Korshunova et al. 2017a). Both species have, however, been recorded from Norway based on DNA barcoding ( Bakken et al. 2024a). Prior to 2017, the two species were treated as one under the name Flabellina pellucida . F. pellucida has been recorded north to Trøndelag in mid-Norway ( Evertsen & Bakken 2005). Recently, F. pellucida was also reported from Russian waters for the first time ( Ekimova et al. 2019). The present study found Carronella to be commonly occurring in the Tromsø region, thus bridging the gap in distribution between mid-Norway and Russia. Animals were found all year round except during summer. Spawning was observed in spring. True identity of the specimens collected in the present study (here reported as Carronella sp. ) as well as from other regions remains to be ascertained. The records in the present study are the first of Carronella from the Tromsø region.

Edmundsella pedata (Montagu, 1816) Figure 5C

Material examined: One specimen, SFJ, 04 July 2021, FB, NUIT-1035 ( Figure 5C ) .

Localities: SFJ

Distribution and remarks: Edmundsella pedata has, under the name Flabellina pedata , previously been recorded in southern Norway ( Evertsen & Bakken 2005; Lundin et al. 2020). Moen and Svensen (2020) also mention observations north to Nordland. The present record is the first record from the Tromsø region and represents a significant range extension in distribution.

Figures

Figure 5. A. Coryphella verrucosa, verrucosa form, NTNU-VM-85676/NUIT-1261, B. Carronella sp., NTNU VM-84466/NUIT-1121, C. Edmundsella pedata, NUIT-1035, D. Cuthonella concinna, NUIT-1011, E. Cuthona nana, NTNU VM-85646/NUIT-1242, F. Amphorina andra, yellow form, NTNU-VM-85702/NUIT-1236, G. Amphorina andra, white form, NTNU-VM-84468/NUIT-1032, H. Amphorina andra, white-orange form, NTNU- VM-84496/NUIT-1006-1, I. Amphorina pallida, strongly pigmented form, photo record, 12 December 2020, J. Amphorina pallida, pale form, photo record, 01 February 2022, K. Eubranchus exiguus, NUIT-1334, L. Eubranchus rupium, photo record, 17 August 2021. Scale bar: 10 mm. All photos: Fredrik Broms.