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Study of the diet of squid is hampered by the fact that these animals masticate their prey prior to ingestion and do not necessarily ingest the hard parts that allow the identification of prey remains present in the stomach. The result is a large percentage of prey in stomach contents that can be identified only according to broad categories (e.g., "teleost fish"). This is widely described in the literature and has also been found in samples from the English Channel of the two loliginid squid fished in this area (Loligo forbesii and Loligo vulgaris). New biological samples of both species were collected at the Port-en-Bessin fish market during the 2019–2020 fishing season. Stomach contents were studied through DNA metabarcoding targeting a small fragment of the COI mitochondrial gene selected by PCR and sequenced using high-throughput next generation sequencing. The DNA metabarcoding results were compared with databases available online. These preliminary results validated a protocol based on commercial samples kept frozen (−20 °C) before analysis. Sequences allowed 34 different types of prey to be identified to the species level, including 17 teleost fish species. Results revealed the high occurrence of cuttlefish eaten by both species of squid. Food composition was analysed in order to make comparisons between species, between seasons (in L. vulgaris) and according to the size of the predator. Differences in diet of L. vulgaris between November and March samples were greater than the difference between L. vulgaris and L. forbesii, which is consistent with opportunistic behaviour in these squids. Differences in diet related to predator size do not suggest a change in trophic level during the growth of recruited stages. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Progress in the analysis of English Channel loliginid squid diets using DNA-metabarcoding techniques" published in Marine Biology. The correction states that the title of the article was incorrectly given as 'Progress in the analysis of english channel loliginid squid diets using DNA-metabarcoding techniques' and should have been 'Progress in the analysis of English Channel loliginid squid diets using DNA-metabarcoding techniques'. Additionally, the correction mentions that references with scientific names of species have been changed and italicized. The original article has been corrected. The correction notice does not provide any further information about the content of the article or its findings. [Extracted from the article]

Length–frequency analysis was employed to resolve multiple cohorts in the Loligo forbesi population from coastal waters to the west of Scotland. In both male and female squid two principal cohorts were identified, recruiting to the fished population in April and November. Both cohorts spawned during the winter months (November to April), producing a single extended spawning season, with the April recruits of larger size at spawning than the November recruits. In the males the April recruits appeared to separate into two cohorts of different growth rates, thus producing three rather than two sizes at maturity. The abundance of L. forbesi was low during the summer months, indicating that the squid had moved outside the range of the fishery, perhaps into deeper water. Abundance declined during the spawning season, which is interpreted as post-spawning mortality. Abundance declined earlier in the males than females, producing a female biased sex ratio during most of the spawning season. The two periods of recruitment are not compatible with a 1 year life cycle and single extended spawning season and explanations of this are discussed. [ABSTRACT FROM PUBLISHER]

Length-frequency data on squid (Loligo forbesi) collected during trawling surveys in Scottish waters from 1980 to 1994 were analysed to describe temporal and spatial patterns in abundance and to examine the prospects for using survey abundance to forecast fishery abundance. Loligo was patchily distributed in space and time. Distribution patterns in the North Sea in February appeared to be strongly related to bottom temperature (squid avoided waters <7°C) and, to a lesser extent, salinity (more squid in more saline water). For other areas and times, no temperature or salinity data were available, but there were trends for squid on the west coast to be more abundant in westerly areas and higher latitudes, and for squid at Rockall to be more abundant in shallow water. Inter-annual trends in abundance differed between the North Sea, west coast and Rockall, but average survey abundances for the North Sea and west coast tended to be positively correlated. For the North Sea and west coast, survey abundance was positively correlated with fishery abundance for the same month and area, and average abundance for the February North Sea survey was a reasonable predictor of commercial CPUE in the autumn of the same year (the peak of the fishery). Some of the observed trends were consistent with the existence of a stock-recruitment relationship but may indicate that abundance in a given calendar year is linked to climatic factors. [ABSTRACT FROM PUBLISHER]