A new species of Cerapopsis (Amphipoda: Corophiidea: Kamakidae) from the Strait of Messina, central Mediterranean Sea

A new species of Cerapopsis (Crustacea: Amphipoda: Kamakidae), C. alexandri sp. nov., is described from the Strait of Messina (central Mediterranean Sea). The specimens were collected in July 2011 and January 2012, in front of the village of Favazzina (Calabria Region, Southern Italy), from 40 to 50m depth. C. alexandri sp. nov. is characterized by head lateral cephalic lobe strongly extended forward, eyes completely enclosed within lobe and peduncolate, anteroventral margin strongly recessed and moderately excavate, male gnathopod 1 slender with carpus elongate, male gnathopod 2 grossly enlarged, and propodus enlarged with posterodistal margin complex. C. alexandri sp. nov. shows a strong sexual dimorphism, evident in gnathopods 1 and 2 morphology and size (smaller in females), and pereopods 3 and 4. The new species differs from described species of the genus (C. longipes and C. takamado) by morphological characteristics of mouth parts; male gnathopod 2, in which propodus shows posterodistal teeth long and slender; telson; epimeral plate 3; and uropod 1 and 2 marginal spinulation. Different male paratypes are also described, showing the morphological variability within the species. The main morphological difference between the holotype and paratypes occurred in gnathopod 2. The genus Cerapopsis is now known to contain three species.