Description, systematics and ecology of a new tanaidacean (Crustacea, Peracarida) species from mediterranean fish farms

Abstract

An undescribed species of tanaidacean belonging to the genus Hexapleomera, tribe Pancolini, Hexapleomera bultidactyla sp. nov. was found in fouling community samples from off-coast fish farms cages in the western Mediterranean Sea. The species can be distinguished from other Hexapleomera species by the presence of a ventral apophysis on the dactylus of the chela in males. Other diagnostic characters (in combination) include a male antennule with five aesthetascs, the female with three, the maxillule palp with four terminal setae and maxilliped basis and coxa each with two setae; the male fixed finger with four ventral setae and proximal apophysis, the female chela fixed finger with a proximal triangular apophysis, an apophysis on the coxa of pereopod 1, a pleopod 3 basis with three outer setae, and an uropod of four segments. Although several substrata were investigated, the species was most abundant where the turf formed by Ceramiaceae algae and the hydroid Aglaophenia sp. was dominant. An updated identification key to all the species of Hexapleomera is provided.

Tanaididae (Crustacea, Tanaidacea, Tanaidomorpha, Tanaidoidea) on a Floating Dock, West Beach, Adelaide, South Australia: Introduced or Indigenous?

“…Detailed morphological studies and molecular data have provided evidence refuting earlier suggestions of cosmopolitan distributions of several Tanaidacea (Sieg 1980;Bamber 2012a;Błażewicz-Paszkowycz et al 2012;Larsen et al 2014;Larsen 2014). However, Tanaidacea of the genus Hexapleomera Dudich, 1931(Family Tanaididae Nobili, 1906 were found on the hulls of yachts (Bamber 2012a) and in fouling communities from harbours (Tanabe & Kakui 2019) and fish farms (Esquete & Fernandez-Gonzalez 2016). They are also epibionts on loggerhead sea turtles (Moore 1894;Sieg 1980;Edgar 2008;Tanabe et al 2017;Tanabe & Kakui 2019) and the Caribbean manatee (Morales-Vela et al 2008).…”

“…Sexual dimorphism in cheliped pronounced; chela in sexually dimorphic males about 1.5 times wider than chelipedal carpus." Tanabe et al (2017) excluded the character "pereonites 1 to 3 together being wider than long" from the previous diagnosis of Bamber (2012a), with justification based on non-conformity with this character by H. bultidactyla Esquete &Fernandez-Gonzalez, 2016 andH. wombat Bamber, 2012.…”