Three new species of snapping shrimps of the genus Alpheus are described from the Persian Gulf. These belong to the Alpheus edwardsii species-group, which is mainly characterized by unarmed orbital hoods and the presence of dorsal and ventral notches on the palm of the major chela. Alphus ankeri sp. nov. shows a close affinity to A. pacificus Dana, 1852 and A. heronicus Banner & Banner, 1982 bearing no balaeniceps crests in both sexes on the dactylus of the minor chela, and the merus of the major chela of both sexes are unarmed. This species differs from the closely related species by the absence of an overhanging proximal shoulder in the major chela. The other rock crevice inhabiting species, A. mohammadpouri sp. nov. is diagnosed by exhibiting sexual dimorphism in its balaeniceps crests and the armed merus of the major chela. These two characters are similar to those recorded for three sandy/rubble dwelling species: A. inopinatus Holthuis & Gottlieb, 1958, A. lobidens De Haan, 1849 and A. australiensis Banner & Banner, 1982. This new species is distinguishable from these latter species by the shape of the minor chela and colour pattern. A coral inhabiting species A. abumusa sp. nov. appears to be closely related to A. maindroni Coutière, 1898, showing an armed merus of the major chela and the absence of spine-like seta on the ischia of the third legs. This last new species is easily discriminated from A. maindroni by longer antennular segments, a markedly concave frontal margin between the rostrum and orbital hood, and a different colour pattern.

Here we present a comparison of saddle and eye patch patterns of killer whales from Norwegian, Icelandic, British, Spanish and Greenlandic waters. We found only a small amount of variation in saddle patch shapes, which may reflect a recent phylogenetic divergence from the most recent common ancestor. Eye patch shapes were more variable than saddle patches in small details. Most individuals had eye patches with parallel orientation, with the exception of a small group of killer whales from the Hebrides, which, as previously reported, had sloping eye patches that sloped downward at the posterior end. This differentiation in pigmentation patterns of the Hebridean killer whales from neighbouring populations could reflect one or more of several evolutionary processes, including a deeper phylogenetic divergence, low gene flow with other local populations and drift.

Studies on differences in external morphology and pigmentation patterns were historically carried out using stranded individuals or opportunistic sightings; few studies have involved sampling systematically free-ranging individuals. In order to investigate and describe main pigmentation characteristics, outlining ‘typical’ regional pigmentations, this work analysed systematic photographic information taken on free-ranging striped dolphins, Stenella coeruleoalba. Photographs of dolphins in the Ligurian Sea were collected between May 2004 and December 2006. All individuals were described by the presence/absence of pigmentation variables and by differences in colour shades. The frequency of all the pigmentation variables analysed is stable in the population (10 ‘gene’ variables, 19 ‘allele’ variables), and remains similar between each different group of dolphins. But population presents widespread pigmentation variability between specimens, allowing identification even at single individual level. Cluster analysis also found that the majority of the pigmentations derive from two main colour patterns, called ‘mat’ and ‘pale’ patterns (fmat = 0.68; fpale = 0.12). The Bray–Curtis index showed a high variability of the intra-group pigmentation distance between groups. This resulted in a positive correlation between group size and ‘intra-group’ pigmentation distance: the distance increases rapidly up to a group size of 40 individuals. According to the results obtained, the striped dolphins seem to be concentrated in small groups in which there is a large phenotypic similarity among individuals. These small units could be associated between them to form temporary large groups observed only in pelagic waters.

The taxonomy of the snapping shrimp Alpheus cristulifrons Rathbun, 1900, previously reported from the eastern Pacific and western and eastern Atlantic, is reviewed based on molecular data (COI), morphology and colour patterns. Three species are recognized in the A. cristulifrons species complex. Alpheus cristulifrons sensu stricto is restricted to the western Atlantic, ranging from Florida and the Caribbean Sea to southern Brazil. The eastern Pacific A. cristulifrons sensu Kim & Abele, 1988 corresponds to A. utriensis Ramos & Von Prahl, 1989, ranging from the Gulf of California to Colombia; this species can be separated from A. cristulifrons by the absence of balaeniceps setae on the male minor chela and the presence of bands on the antennular and antennal flagella. The eastern Atlantic A. cristulifronssensu Crosnier & Forest, 1966 is described as A. xanthocarpus sp. nov. based on recently collected material from the island of São Tomé in the Gulf of Guinea; this species differs from A. cristulifrons by the posteriorly more extending rostral carina and the presence of conspicuous yellow spots on the carpus and chela of the second pereiopod. Molecular data suggest that A. utriensis is the eastern Pacific sister clade to the amphi-Atlntic clade that includes A. cristulifrons and A. xanthocarpus sp. nov.