Zeuxo exsargasso Sieg

Larsen, Kim, Nagaoka, Ryoko & Froufe, Elsa, 2012, Tanaidacea (Crustacea) from Macaronesia III. The shallow-water Tanaidomorpha from the Cape Verde archipelago, Zootaxa 3498, pp. 24-44 : 42-43

Zeuxo exsargasso Sieg

Material examined. Mindelo marina (sandy bottom algae) and Mindelo beach (hard bottom algae), St. Vicente Island, Cape Verde, Ten non-ovigerous females, 18 ovigerous females, nine males, 30+ manca. Collected by K. Larsen by snorkeling, 0.5 to 1.5 meters.

Remarks. Zeuxo exsargasso will be redescribed in another paper (Larsen et al, research in progress) for the purpose of having a description to accompany gene sequences lodged in Genbank but in summary, we observed the following differences in our specimens relative to those described by Sieg (1980): Antenna article 2 with dorsal serration. Labium with outer spines. Maxilliped palp article 1 with outer serration; endites with two small inner distal setae. Cheliped dactylus with inner spines and medial seta. Zeuxo exsargasso was described by Sieg (1980) as having two inner setae on the pleopodal endopod, while this is in conflict with the diagnosis of the subgenus Parazeuxo , also by Sieg (1980). In this study the pleopod 1 endopod had only one inner seta. Uropodal article number varies between five and six (even within individuals).

Zeuxo exsargasso was initially recorded from floating Sargassum natans off Bermuda (Sieg 1980) but was later reported from benthic intertidal algae off the Canary Islands by Bamber & Costa (2009; this study), and now from benthic intertidal algae off the Cape Verde archipelago ( Bamber, 2012; this study). Recently Bamber (2012) described Zeuxo coturnix from Cape Verde and separates this from Z. exsargasso on the basis of cheliped- and maxillular setation as well as on differences in pigmentation pattern and uropod article number. While we do accept Z. coturnix as a valid species on the basis of the cheliped- and maxillular setation, we would like to point out that the pigmentation and uropod characters are subject to variation within Z. exsargasso , the latter even within the individual specimen (Larsen et al, research in progress). The unique pigmentation pattern described for Z. coturnix ( Bamber 2012:13) was also found in specimens genetically identical to Z. exsargasso (Larsen et al, research in progress).