“New records of rare species in the Mediterranean Sea” (October 2021)

“New records of rare species in the Mediterranean Sea” (October 2021

Working group on cephalopod fisheries and life history (Wgceph; outputs from 2022 meeting)

Rapports Scientifiques du CIEM. Volume 5, nº 1WGCEPH worked on six Terms of Reference. These involved reporting on the status of stocks; reviewing advances in stock identification, assessment for fisheries management and for the Ma- rine Strategy Framework Directive (MSFD), including some exploratory stock assessments; re- viewing impacts of human activities on cephalopods; developing identification guides and rec- ommendations for fishery data collection; describing the value chain and evaluating market driv- ers; and reviewing advances in research on environmental tolerance of cephalopods. ToR A is supported by an annual data call for fishery and survey data. During 2019–2021, com- pared to 1990–2020, cuttlefish remained the most important cephalopod group in terms of weight landed along the European North Atlantic coast, while loliginid squid overtook octopus as the second most important group. Short-finned squid remained the least important group in land- ings although their relative importance was almost double in 2019–2022 compared to 1992–2020. Total cephalopod landings have been fairly stable since 1992. Cuttlefish landings are towards the low end of the recent range, part of a general downward trend since 2004. Loliginid squid landings in 2019 were close to the maximum seen during the last 20 years but totals for 2020 and 2021 were lower. Annual ommastrephid squid landings are more variable than those of the other two groups and close to the maximum seen during 1992– 2021. Octopod landings have generally declined since 2002 but the amount landed in 2021 was higher than in the previous four years. Under ToR B we illustrate that the combination of genetic analysis and statolith shape analysis is a promising method to provide some stock structure information for L. forbsii. With the sum- mary of cephalopod assessments, we could illustrate that many cephalopod species could al- ready be included into the MSFD. We further provide material from two reviews in preparation, covering stock assessment methods and challenges faced for cephalopod fisheries management. Finally, we summarise trends in abundance indices, noting evidence of recent declines in cuttle- fish and some octopuses of the genus Eledone. Under ToR C, we describe progress on the reviews of (i) anthropogenic impacts on cephalopods and (ii) life history and ecology. In relation to life history, new information on Eledone cirrhosa from Portugal is included. Under ToR D we provide an update on identification guides, discuss best practice in fishery data collection in relation to maturity determination and sampling intensity for fishery monitoring. Among others, we recommend i) to include the sampling of cephalopods in any fishery that (a) targets cephalopods, (b) targets both cephalopods and demersal fishes or (c) takes cephalopods as an important bycatch, ii) Size-distribution sampling, iii) the use of standardized sampling pro- tocols, iv) an increased sampling effort in cephalopod. Work under ToR E on value chains and market drivers, in conjunction with the Cephs & Chefs INTERREG project, has resulted in two papers being submitted. Abstracts of these are in the report. Finally, progress under ToR F on environmental tolerance limits of cephalopods and climate en- velope models is discussed, noting the need to continue this work during the next cycle.info:eu-repo/semantics/publishedVersio

Length–weight relations of 16 mesopelagic fishes (Actinopterygii: Myctophiformes and Stomiiformes) from the eastern Mediterranean Sea

For many mesopelagic fishes, even basic knowledge regarding their biology is missing, greatly impeding their effective management. Here we present length–weight relations for 16 mesopelagic fishes sampled during research surveys in the Greek seas (eastern Mediterranean). The following species were studied: Benthosema glaciale (Reinhardt, 1837); Ceratoscopelus maderensis (Lowe, 1839); Diaphus holti Tåning, 1918; Diaphus metopoclampus (Cocco, 1829); Diaphus rafinesquii (Cocco, 1838); Hygophum benoiti (Cocco, 1838); Hygophum hygomii (Lütken, 1892); Lampanyctus crocodilus (Risso, 1810); Lobianchia dofleini (Zugmayer, 1911); Myctophum punctatum Rafinesque, 1810; Notoscopelus elongatus (Costa, 1844); Symbolophorus veranyi (Moreau, 1888) [Myctophidae]; Argyropelecus hemigymnus Cocco, 1829; Maurolicus muelleri (Gmelin, 1789) [Sternoptychidae]; Stomias boa (Risso, 1810); Chauliodus sloani Bloch et Schneider, 1801 [Stomiidae].With the exception of Diaphus holti and Symbolophorus veranyi, parameter b diverged significantly from isometry. Only two species (Benthosema glaciale and Chauliodus sloani) displayed negative allometry, while for the remaining 12 species a positive allometry was found, with the highest parameter b values estimated for Stomias boa and Diaphus rafinesquii. The median value of parameter b for all species was 3.236 and 50% of its values ranged from 3.173 to 3.323. Some variations of the parameter b were observed between our findings and other studies from the Atlantic and the western Mediterranean

New records of rare species in the Mediterranean Sea (October 2021)

This Collective Article presents information about 27 taxa belonging to five Phyla (one Ochrophyta, one Cnidaria, three Arthropoda, two Mollusca and twenty Chordata) and extending from the Western Mediterranean Sea to the Levantine Sea and the Black Sea (Sea of Marmara). The new records were reported from 11 countries as follows: Algeria: occurrence of the African striped grunt Parapristipoma octolineatum; Spain: new records of eight uncommon fish species (Gadella maraldi, Hypleurochilus bananensis, Lobotes surinamensis, Parapristipoma octolineatum, Selene dorsalis, Sphoeroides marmoratus, Tetragonurus cuvieri, and Trachyrincus scabrus) from the Spanish Mediterranean; Italy: new record of the football octopus Ocythoe tuberculata from the Southern Tyrrhenian Sea; a rare sighting of a juvenile phase of a moray eel of the genus Gymnothorax, tentatively identified as Gymnothorax cf. unicolor in the Ligurian Sea; first record of adult Facciola's sorcerer Facciolella oxyrhynchus in the Adriatic Sea; occurrence of the tope shark Galeorhinus galeus in the Northern Adriatic Sea; Libya: first confirmed record of the pen shell Pinna rudis; first documented record of the palaemonid shrimp Brachycarpus biunguiculatus; first record of the fish Sudis hyalina; Malta: new records of Grant's rockling, Gaidropsarus granti; multiple concomitant reports of the rare hydromedusan species Aequorea forskalea; Croatia: a record of the skipjack tuna Katsuwonus pelamis in the Southern Adriatic Sea; Albania: new record of the bigeye thresher shark Alopias superciliosus; Greece: confirmation of the rare brown alga Sargassum flavifolium occurrence in the Eastern Mediterranean Sea; first record of the scaleless dragonfish Bathophilus nigerrimus; Turkey: first occurrence of the calanoid copepod Pteriacartia josephinae in the Aegean Sea; first documented record of the Cremona's sea slug Placida cremoniana for the easternmost Mediterranean Sea; new record of the yellow-headed goby Gobius xanthocephalus in the Sea of Marmara; Cyprus: first record of the Liechtenstein's goby Corcyrogobius liechtensteini; an individual of the Yellow fin tuna Thunnus albacares captured with handline by an artisanal fisher; Lebanon: an individual of the Black marlin Istiompax indica captured in a gill net