Almost 50 years have passed since a group of reputed carcinologists (viz. Lipke B. Holthuis, Isabella Gordon and Jacques Forest) finished the posthumous work of Ricardo Zariquiey Álvarez (1968) on decapod crustaceans of the Iberian Peninsula. No lists of decapod fauna specifically covering this area have been published since then, and an update is needed. The current list of brachyuran crabs of the Iberian Peninsula comprises 140 species, which is 35 species more than the 105 valid species listed in Zariquiey Álvarez (1968). Systematic changes have affected the original classification, so now there are 20 superfamilies, 36 families and 77 genera. Additional species have been recorded in Iberian waters due to natural range expansions from nearby areas (Mediterranean and Atlantic), introductions by anthropogenic activities, and description of new taxa. Also, two species were synonymized. Several of these changes, based on evidence from larval morphology and/ or molecular data, are detailed in this review. Although descriptions of crab species new to science are not expected to occur at a significant rate, an increase in the number of species in the Iberian Peninsula is expected to result from the introduction of alien species.

The scientific exploration of Mallorca Channel seamounts (western Mediterranean) is improving the knowledge of the Ses Olives (SO), Ausias March (AM), and Emile Baudot (EB) seamounts for their inclusion in the Natura 2000 network. The aims are to map and characterize benthic species and habitats by means of a geological and biological multidisciplinary approach: high-resolution acoustics, sediment and rock dredges, beam trawl, bottom trawl, and underwater imagery. Among the seamounts, 15 different morphological features were differentiated, highlighting the presence of 4000 pockmarks, which are seafloor rounded depressions indicators of focused fluid flow escapes, usually gas and/or water, from beneath the seabed sediments. So far, a total of 547 species or taxa have been inventoried, with sponges, fishes, mollusks, and crustaceans the most diverse groups including new taxa and new geographical records. Up to 29 categories of benthic habitats have been found, highlighting those included in the Habitats Directive: maërl beds on the summits of AM and EB, pockmarks around the seamounts and coral reefs in their rocky escarpments as well as fields of Isidella elongata on sedimentary bathyal bottoms. Trawling is the main demersal fishery developed around SO and AM, which are targeted to deep water crustaceans: Parapenaeus longirostris, Nephrops norvegicus, and Aristeus antennatus. This study provides scientific information for the proposal of the Mallorca Channel seamounts as a Site of Community Importance and for its final declaration as a Special Area of Conservation.

The successful settlement of the African pea crab Afropinnotheres monodi in the Bay of Cadiz was analysed to gain new insights into the evolution of pea crab parasite life history traits. The pea crab lives symbiotically and with high prevalence in the bivalves Cerastoderma glaucum and Mytilus galloprovincialis, and with low prevalence in Scrobicularia plana. A remarkable monopolisation of the host (1 crab per bivalve) occurred irrespective of host species and crab demographic categories (males, hard females, soft females), probably as an optimisation of resources in small hosts. However, there was a clear asymmetry in host use by the different crab categories. A 1:1 sex ratio was found in crabs harboured by C. glaucum and S. plana, with most of the female crabs being small and hard specimens, whereas crabs inhabiting M. galloprovincialis were primarily large reproductive females. Ovigerous females were found throughout the year in M. galloprovincialis, and there was a strong correlation between female size and fecundity, suggesting that the females harboured by this host were the major contributors to the reproductive effort of the studied population. Conversely, most of the new crabs recruiting to the population were harboured by the remaining 2 host species. We hypothesise that such a generalist but asymmetrical usage of bivalve hosts by pea crabs may have clear benefits for species such as A. monodi, that are undergoing geographical expansion, facilitating their dispersal to new locations and their successful settlement in sheltered systems, such as the Bay of Cadiz. © Inter-Research 2014.Peer Reviewe

One of the objectives of the LIFE IP INTEMARES project is to assess the impact of bottom trawling on the vulnerable benthic habitats of the circalittoral bottoms of the Menorca Channel (western Mediterranean), designated a Site of Community Importance (SCI) within the Natura 2000 network. The present study compares the epibenthic communities of four areas, subjected to different bottom trawl fishing intensity levels. The assignment of fishing effort levels was based on the fishing effort distribution in the area calculated from Vessel Monitoring System (VMS) data and the existence of two Fishing Protected Zones in the Menorca Channel. Biological samples were collected from 39 beam trawl stations, sampled during a scientific survey on April 2019. We compare the diversity, composition, and density of the epibenthic flora and fauna, together with the rhodoliths coverage and the morphology of the main species of rhodoliths of four areas subjected to different levels of bottom trawl fishing effort, including one that has never been impacted by trawling. Our results have shown negative impacts of bottom trawling on rhodoliths beds and the first signals of their recovery in areas recently closed to this fishery, which indicate that this is an effective measure for the conservation of this habitat of special interest and must be included in the management plan required to declare the Menorca Channel as a Special Area of Conservation.