Blue jack mackerel Trachurus picturatus collected at six sampling locations of the north-east Atlantic Ocean (Azores, Madeira, Canaries, and Matosinhos, Peniche and Portimão, mainland Portugal) and one location in the Mediterranean (Sicily), were used to examine the genetic structure of this species. Three mitochondrial gene regions (cytochrome c oxidase subunit I, cytochrome b and control region) were used to study the genetic structure of the species in Macaronesia, as well as to compare the genetic diversity of this region with published results from its eastern distribution. All markers indicated the absence of genetic structure among populations, with high indices of genetic diversity. These results suggest that the species went through a bottleneck event, followed by a recent population expansion. Moreover, the comparison with previously published results from the T. picturatus Mediterranean distribution suggests the existence of a single panmictic population throughout the species´full range. This was, however, an unexpected result since other methodologies have shown the presence of, at least, three different population-units in the NE

A B S T R A C TThe species belonging to the genus Crangon Fabricius, 1798 only occur in the Northern Hemisphere both in Atlantic and Pacific waters. The higher number of species of Crangon in the Pacific suggests that they originated from this area. To date, a few studies have identified some common features between members of the genus, but the species have largely been ignored in taxonomic, phylogeographic, and ecological research efforts. Crangon are all carnivores or omnivores probably with a relevant ecological role; in some cases top-down control by the type species, C. crangon (Linnaeus, 1758), has been suggested. Several species live in shallow coastal waters and might represent abundant prey for fish including flatfish during their nursery period; the shrimp themselves prey upon the early life stages of flatfish. Because of their high abundance, some shrimp have commercial value not only for human consumption but also as bait. However, the taxonomic status within Crangon and genetic relationships among populations within species are still unsettled. Also, their geographic ranges and general life cycle features are poorly documented. Despite occurring only in the Northern Hemisphere, Crangon are originally temperate water species. Most have still a high upper tolerance limit but are also quite adapted to low temperatures. They might then have a high temperature tolerance range which will be beneficial in a climate change scenario. In this work we review previous investigations on the various species of Crangon across the spread of their geographic occurrence and highlight issues requiring further research.

The Atlantic chub mackerel (Scomber colias) is an important commercial fish species of the Northeast Atlantic. Two-year-old individuals collected between January and April of 2018 at six sampling locations (45 fish per site) of the Northeast Atlantic (Azores, Madeira, Canaries and mainland Portugal-Matosinhos, Sesimbra and Portimão) were used for body morphometrics and otolith-shape analyses. Data were analysed by univariate and multivariate statistics. Re-classification success using shape analyses and body morphometrics showed an overall rate of 51 and 74% respectively. Regional differences regarding the otolith-shape analyses suggested a single stock, not necessarily homogenous, with a discrete separation of two main groups (oceanic islands and mainland Portugal). However, body morphometrics showed a more detailed separation in two main groups (Canaries and the others, but with a slight differentiation between fish from Azores-Madeira and mainland Portugal). Moreover, joint analyses gave an overall re-classification success of 82% and allowed a more comprehensive scenario, showing the existence of three main groups (Canaries, Azores-Madeira and mainland Portugal). Regional differences are probably related with different oceanographic conditions influencing the feeding regime and fish growth. The hereby data suggest that S. colias caught in the Northeast Atlantic are different population units, and we recommend a fishery management at a finer regional scale.

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To study some early life history traits of Lipophrys pholis, 110 recruits (TL ≤ 30 mm) were collected in April and May 2013 during the low tide periods in four rocky beaches along the west (Cabo do Mundo, Peniche and Vale do Homem) and south (Olhos de Água) Portuguese coasts. Pelagic larval duration, size at settlement and age at coastal recruitment were back-calculated from the microstructure of otoliths. Pelagic larval duration estimated from micro-increment counts until the settlement marks ranged from 57 to 73 days and showed a latitudinal reduction trend from north to south. This variable seems to be related in 30% with the regional seawater temperatures probably through the direct effect on the somatic growth. Settlement sizes (~19 mm) did not show any regional differences suggesting that this is a more conservative character within species. The mean age at coastal recruitment varied between 69 and 93 days, but northern individuals were recruited at an older age. Back-calculated spawning, hatching and settlement dates appear to be unrelated to the lunar cycle for L. pholis.