Observation of Abundant Larval Arctic Shanny (Stichaeus punctatus) in the Western North Atlantic, Found in the Waters of the Isles of Shoals, Maine, USA
Information about the life history of larval fishes can be sparse, especially at the edges of typical geographic ranges and among fishes for which there is no commercial fishery. We report a new observation of larval Arctic Shanny (Stichaeus punctatus) far south of their typical geographic range in the western North Atlantic. Only two previous records of adult of S. punctatus have been documented in this region, and there has only been one previous report of larvae in US Atlantic waters. From May through July 2018, we observed large numbers of larval S. punctatus by night-lighting off a dock at Shoals Marine Laboratory on Appledore Island, Maine, in the Gulf of Maine. We include approximations of catch per unit effort (number of larvae per ten-minute sampling interval) throughout the sampling period and information regarding identifying features. The high number of larvae seen could indicate that the Isles of Shoals is a spawning locality for this species and could indicate a future increase in their abundance in the southern Gulf of Maine.

Microscopy photographs of larvae of Stichaeus punctatus. These photographs of live fishes demonstrate pigment patterns and vent position. The image of the whole body (A) shows the overall pigment pattern. The image of the anterior region of the fish (B) shows the melanophores on the head and along the dorsal surface of the gut to the vent. The image of the caudal region (C) shows the ventral hypaxial myomere pigment. Scale bars represent 1 mm.

Color illustration of larvae of Stichaeus punctatus. This illustration shows melanophores and color patterns. Scale bar represents 1 mm.

Approximate Catch Per Unit Effort (CPUE) of larval Stichaeus punctatus during the sampling period. We sampled larvae weekly by night-lighting from 23 May to 18 July 2018. We defined CPUE as number of larvae per ten-minute interval. Sampling periods ranged from 40–90 minutes, except on 18 June when sampling was shortened to 20 minutes due to rain and wind (denoted with an asterisk).
Contributor Notes
Associate Editor: D. Buth.