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The velvet belly lanternshark (Etmopterus spinax) is a small, bioluminescent shark that is caught as bycatch in many deep-sea fisheries in the Atlantic Ocean. Using data from 10,597 seasonal research survey tows spanning 11 years, the distribution, relative abundance, life history, and environmental preferences of E. spinax in Icelandic waters was examined for the first time. E. spinax (n = 8774) were only captured in relatively deep offshore waters to the south and west of Iceland. Females grew to larger sizes than males and reached 50% sexual maturity at a total length of 50 cm. Females at a late stage of maturity and very small juveniles (</div

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The velvet belly lanternshark (Etmopterus spinax) is a small, bioluminescent shark that is caught as bycatch in many deep-sea fisheries in the Atlantic Ocean. Using data from 10,597 seasonal research survey tows spanning 11 years, the distribution, relative abundance, life history, and environmental preferences of E. spinax in Icelandic waters was examined for the first time. E. spinax (n = 8774) were only captured in relatively deep offshore waters to the south and west of Iceland. Females grew to larger sizes than males and reached 50% sexual maturity at a total length of 50 cm. Females at a late stage of maturity and very small juveniles (</div

Histogram (top) and cumulative distribution function (CDF) (bottom) of tow depth during the 2010–2021 MFRI research surveys.

Stations where E. spinax was caught during the spring and autumn research surveys are shown in orange and green, respectively. The black dashed line shows the depth CDF for all stations in spring, while the dotted black line shows the depth for all stations in the autumn.</p

Distribution of mature female E. spinax caught during the 2010–2021 autumn research surveys.

Maturity stage 5 (n = 17) shown in blue, maturity stage 6 (n = 4) shown in orange, all mature stages (3–7; n = 111) shown in magenta, stations with no mature females shown in grey. Maturity stages 5 and 6 are both pregnant females, where stage 5 has small embryos and stage 6 has fully developed embryos.</p

Seasonal variation in distribution of E. spinax caught during the 2010–2021 MFRI spring (green) and autumn (orange) research surveys, whereby the size of the symbol is proportional to the number of E. spinax in the catch.

Grey circles represent null catches. A total of 3950 sharks were caught in the spring survey, and 4614 sharks in the autumn survey.</p

A histogram showing the differences in length distribution of caught E. spinax for males (blue) and females (red).

A histogram showing the differences in length distribution of caught E. spinax for males (blue) and females (red).</p

Annual catch number index of E. spinax (n = 8774) during the 2010–2021 MFRI spring and autumn research surveys.

Annual catch number index of E. spinax (n = 8774) during the 2010–2021 MFRI spring and autumn research surveys.</p

A female Etmopterus spinax (54 cm TL) caught during the autumn research survey in October 2021.

A female Etmopterus spinax (54 cm TL) caught during the autumn research survey in October 2021.</p

Histogram (top) and CDF (bottom) of bottom temperature during the 2010–2021 MFRI research surveys.

Stations where E. spinax was caught during the spring and autumn research surveys are shown in green and orange, respectively. The black dashed line shows the bottom temperature CDF for all stations in spring, while the dotted black line shows the bottom temperature for all stations in the autumn.</p

Distribution of juvenile E. spinax (measuring ≤ 20 cm in total length; n = 298) caught during the 2010–2021 MFRI research surveys.

Expanding symbol sizes are proportional to catch numbers.</p