Lost in the North: The first record of Diretmichthys parini (Post and Quéro, 1981) in the northern North Sea

Abstract

In June 2015, an individual of Diretmichthys parini (Post and Quero, 1981) was trawled at 530m depth, in the North Sea off Norway and donated to research. This capture, the first for this species in the North Sea was the northernmost recorded so far, and provided an opportunity to document some aspects of the biology and ecology of this data-poor species. This individual was a female, 331mm total length of 33years old, with low mercury content in muscle and liver (~0.2μgg wet mass). Stable isotope ratios (C and N) in muscle and liver were consistent with the planktonic diet expected for this species. The capture of this fish at the northern latitude known so far would be consistent with the extension of the home range and the latitudinal shift hypothesized for this species in the 1990's.

Approaching the Arctic: the occurrence of Parin’s spinyfin Diretmichthys parini (Beryciformes: Diretmidae) in the Nordic Seas

“…This could indicate that it is more common than previously thought or, that a northeastward extension of its distribution is about to take place. A northward expansion in the northeastern Atlantic seems to be indicated by catches north to the British Isles in the last decades, as summed up by Cresson et al (2017). The present climate change bringing warmer waters into the Northeast Atlantic (Perry et al 2005, and similar to 'Havbryn', trawling duration and frequency is far higher than scientific surveys.…”

“…The trawler 'Tønsnes' is regularly operating in the Nordic Seas, two specimens reported here represent the second and third records of the Parin's spinyfin off Norway (Figure 1), and the northernmost of these (ZMUB 23826, Figure 2) is close to Arctic waters as delimited by Mecklenburg et al (2018). The first record was reported by Cresson et al (2017) from 62°15'N, 1° 03'E, 277 mm SL, caught in June 2015, at the same time and not far from where the second specimen (ZMUB 23827) was caught. Although the species is undoubtedly rare in the North Atlantic, it has been found frequently in eastern, southern and western parts of Icelandic waters since 1992 (Jónsson & Pálsson 2013).…”

“…The Parin's spinyfin is usually found at depths from 250 to 2000 m (Moore et al 2003, Cresson et al 2017, OBIS database 2019. The western parts of the Nordic Seas are strongly influenced by the East Greenland Current which carries cold water from the Polar Basin and creates subzero water temperatures.…”

“…Little is known about the ecology of D. parini, but small teeth and filtering gill rakers seem to indicate a planktivorous diet (Moore 2016), and stable isotope ratios have recently confirmed this view (Cresson et al 2017). Judged from the fact that a 33 cm TL Parin's spinyfin was estimated from otoliths to be 33 years, the life history might, according to Cresson et al (2017), be similar to that of the slow growing and long-living orange roughy Hoplostethus atlanticus Collett, 1889(see e.g. Minto & Nolan 2006.…”

“…Further north, two specimens have been recorded from Rockall Bank and the Faroe-Scotland Ridge at about 60°N (Quero et al 1998). A specimen caught in the North Sea at 62°15'N, for which also biological parameters were investigated (Cresson et al 2017), was claimed to represent the northernmost record. However, Parin's spinyfin is caught almost annually off the eastern, southern and western coast of Iceland, close to 66°N (Jónsson & Pálsson 2013).…”