Early prey intake of a short-finned pilot whale (Globicephala macrorhynchus Gray, 1846, Cetacea: Delphinidae) in the Canary Islands.

This study reveals early prey eating by a short-finned pilot whale (Globicephala macrorhynchus Gray, 1846, Cetacea: Delphinidae) in the Canary Islands. Stomach contents, trophic markers, skin isotopic ratios of nitrogen (δ15N:15N/14N) and carbon (δ13C:13C/12C), and fatty acid profiles of the blubber of a short-finned pilot whale of 213 cm size euthanized in free-ranging conditions were analyzed. A total of 15 species of oegopsid squids, mostly diel vertical mesopelagic migrant species of the families Enoploteuthidae, Ommastrephidae, and Histioteuthidae, as well as mother's milk, were identified in the stomach contents. Asperoteuthis acanthoderma (Lu, 1977, Cephalopoda: Chiroteuthidae) was found as first time in this area, suggesting the possibility of its presence on both sides of the subtropical Atlantic, extending its current known distribution. The δ15N value (11.55‰) was higher than expected based on the size range of squid ingested, but lower than that of adult pilot whales, suggesting that mother's milk intake has a significant effect on these values in calves. Similarly, the δ13C values (-17.99‰) were shifted to those of adult pilot whales rather than the ingested squids, also due to the ingestion of high-fat breast milk. The fatty acid (FA) composition of blubber showed a clear stratification. Long-chain polyunsaturated fatty acids (LC-PUFA) were mainly present in the inner layer, while most relevant ≤C20 monounsaturated fatty acids (MUFA) were more abundant in the outer layer.

Assessments of metallic contents in rare cephalopods from the Canary Islands: relationships with depth habitat and body size.

This study investigated 20 elements in the muscle of 11 cephalopod species caught in the Canary Islands inhabiting from coastal to meso-bathypelagic habitats. Among them, trace element contents from large and elusive cephalopods such as Architeuthis dux, Taningia danae, Lepidoteuthis grimaldii, and Haliphron atlanticus were determined. Statistically significant differences in element concentration were found among class sizes and habitat. Large species that are inhabiting in deepest waters such as Loligo forbesii, A. dux, T. danae, H. atlanticus, and L. grimaldii showed a high load and variability in Fe and Al, while coastal species were characterized by a homogeneous element composition, being the Zn loads highest than other elements. Metal contents in large and elusive cephalopod species were dominated by Fe, Ni, Al, Zn, and Sr, with these species being able to carry important amounts of these elements to predators such as deep-diving odontocetes that reside around the Canary waters.

New Data on the Systematics of Comb-fin Squids Chtenopteryx spp. (Cephalopoda: Chtenopterygidae) from the Canary Islands.

Alejandro Escánez, Álvaro Roura, Rodrigo Riera, Ángel Francisco González, and Ángel Guerra (2018) The systematics of the comb-fin squid species is problematic and poorly resolved. In total, 53 specimens of comb-fin squids (Chtenopteryx spp.) were caught at depths ranging from 30 to 800 m off the Canary Islands (NE Atlantic Ocean). Mantle lengths of the individuals ranged from 18 to 43 mm and the sample included immature, mature male and mature female specimens. Two species of comb-fin squids, Chtenopteryx canariensis and C. sicula, were identified by combining traditional morphological characters with a molecular analysis of a fragment of the cytochrome c oxidase subunit I (COI) gene. Intra- and interspecific genetic distances and maximum likelihood tree analyses based on COI sequences available from GenBank suggest the existence of at least four species, two from the Pacific and two from the Atlantic Ocean. Our data expand the current geographic range of C. canariensis from the NE to NW Atlantic. In the GenBank database, several sequences of comb-fin squid in different species-specific clades have been attributed only to C. sicula, indicating the possible existence of cryptic species and the need to re-analyse these data.

Influence of the submarine volcanic eruption off El Hierro (Canary Islands) on the mesopelagic cephalopod's metal content.

This work investigates whether a submarine volcanic eruption off El Hierro (Canary Islands) in October 2011 influenced the metal contents of two deep water cephalopod species: Abraliopsis morisii and Pyroteuthis margaritifera. This was assessed by comparing metal contents in specimens collected off the island of El Hierro and in the neighbouring islands of La Palma and Tenerife during an experimental deep water fishing trip. The concentration of 20 heavy metals was analyzed in 180 specimens of A. morisii and P. margaritifera collected around the three islands to test for inter-island differences for each species and metal. While both species showed geographical differences in metal concentrations, the main finding was that A. morisii could be a bioindicator species for metals such as Li, Sr and Ca.