Coryphella chriskaugei (Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, Saito, Lundin, Schrödl & Picton, 2017 )

Broms, Fredrik, 2024, Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway, Fauna norvegica 43, pp. 84-109 : 97-99

Coryphella chriskaugei (Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, Saito, Lundin, Schrödl & Picton, 2017)

Figure 4G

Material examined: One specimen, HIL, 18 October 2020, FB, photographic record ( Figure 4G ) ; One specimen, HIL, 27 November 2021, 22 mm, FB, NUIT-1072 ; Three specimens, HIL, 15 October 2022, 22, 31, 15 mm, FB, NUIT-1226, NUIT-1233, NTNU-VM-85704/ NUIT-1250 ; One specimen, HIL, 14 November 2023, 16 mm, FB, NUIT-1340 .

Localities: HIL, SFJ

Distribution and remarks: Coryphella chriskaugei was described as recently as in 2017 ( Korshunova et al. 2017a). While described under the name Fjordia chriskaugei it is currently placed under the genus Coryphella ( Ekimova et al. 2022; WoRMS 2024). Prior to 2017 it was included under the name Flabellina lineata Lovén, 1846 . However, following recent major revision and reclassification ( Korshunova et al. 2017a) animals previously recorded as Flabellina lineata may now refer to any of several different species. According to the review by Evertsen and Bakken (2005), Flabellina lineata was found to be distributed along the entire Norwegian coast, including the Tromsø region but as indicated above it is not known which species was recorded. In this study, C. chriskaugei was observed mainly during winter in association with Ectopleura larynx but was also found once during summer on Tubularia indivisa Linnaeus, 1758 . The present records are the first records from Tromsø and the northernmost known records of the species.

Coryphella gracilis (Alder & Hancock, 1844) Figure 4H

Material examined: One specimen, THA, 28 September 2020, FB, photographic record ; One specimen, TPR, 22 November 2021, 7 mm, FB, NTNU-VM-85715/NUIT-1066 ( Figure 4H ) ; Two specimens, TPO, 16 February 2022, 11, 10 mm, NTNU-VM-84568/NUIT-1134, NUIT-1135 ; One specimen; THA, 24 March 2022, 9 mm, FB, NTNU- VM-85682/NUIT-1151 ; One specimen; TPO, 07 October 2023, 10 mm, FB, NUIT-1328

Localities: ESU, HIH, HIL, THA, TPO, TPR

Distribution and remarks: Records of Coryphella gracilis are relatively few and the species has been categorized as having a southernly distribution in Norway ( Evertsen & Bakken 2005). Using DNA barcoding, larvae of C. gracilis have, however, recently been detected in the meroplankton in the Barents Sea ( Descôteaux et al. 2021, 2022). The present study found C. gracilis to be a commonly occurring nudibranch in the Tromsø region. Animals were observed all year around where they were mainly associated with Eudendrium sp. hydroids. Spawning was mainly observed during April – June but was also observed in the autumn. The present records are the first records from the Tromsø region and constitute a new northernmost distribution record of adult specimens of the species.

Coryphella lineata ( Lovén, 1846) Figure 4I

Material examined: One specimen, HIL, 15 October 2022, 36 mm, FB, NUIT-1232 ( Figure 4I ) .

Localities: HIL

Distribution and remarks: Coryphella lineata was, together with several other species, previously known under the name Flabellina lineata . Flabellina lineata has been recorded from the entire Norwegian coast including one record from Tromsøsundet in 1885 ( Sparre-Schneider 1885). All old records are, however in need of re-examination to be able to verify species identity. Following the characters given in the recent taxonomic reassessment of the family Flabellinidae ( Korshunova et al. 2017a) , the present record is the first published record of Coryphella lineata from the Tromsø region.

Figures

Figure 4. A. Aeolidia papillosa, NUIT-1257, B. Aeolidiella glauca, NUIT-1309, C. Facelina auriculata, NTNU VM-85680/NUIT-1175, D. Facelina bostoniensis, photo record, 18 October 2020, E. Favorinus branchialis, photo record, 18 October 2020, F. Coryphella browni, NTNU VM-84427/NUIT- 1104, G. Coryphella chriskaugei, NUIT-1233, H. Coryphella gracilis, NTNU VM-85715/NUIT-1066, I. Coryphella lineata, NUIT-1232, J. Coryphella cf. monicae, NUIT-1275, K. Coryphella cf. orjani, NTNU VM-85713/NUIT-1124, L. Coryphella verrucosa, rufibranchialis form, NTNU VM-85655/ NUIT-1263. Scale bar: 10 mm. All photos: Fredrik Broms.