Brunarus, Bamber, Roger N. & Marshall, David J., 2015

Bamber, Roger N. & Marshall, David J., 2015, Tanaidaceans from Brunei, V. The Leptocheliidae (Crustacea: Peracarida: Tanaidacea), with four new species, Zootaxa 3948 (3), pp. 342-360 : 343

Genus Brunarus gen. nov.

Diagnosis: Female: Antennule distinct flagellar segment absent. Cephalothorax 1.5 times as long as wide, with demarcation of second thoracomere by a slight groove. Cheliped carpus with two setae along dorsal margin. Pereopod 1 basis dorsoproximal seta almost as long as basis width; ischium of with two setae; carpus longer distal seta shorter than carpus; dactylus proximal seta. Pereopods 2 and 3 with two setae on ischia. Pereopods 4–6 merus with tubercle-mounted setae (or setose tubercles); propodus dorsodistal setae. Uropod exopod two-segmented. Body length about 8.5 times width. Male: unknown.

Type species. Brunarus colekanus sp. nov. by original designation.

Etymology. Brunarus is a concatenation of Brunei and Konarus Bamber, 2006 , the type-genus of the Konariinae .

Gender. Masculine.

Remarks. The five genera previously described in the subfamily Konariinae are diagnosed and keyed in Bamber (2013b), wherein Brunarus gen. nov. keys out to Pseudoleptochelia Lang, 1973 . It differs from that genus, and indeed all other konariin genera, in the absence of an inner seta on the pleopod endopod and basis, and having pointed distal spines on the maxilliped endite adjacent to a blunt-tipped lateral seta.

Within the Leptocheliidae , pointed maxilliped endite spines are found in the presumed-plesiomorphic genus Catenarius Bamber, 2008 , although that genus has a normal adjacent lateral seta and is not a konariin. Other differences from Pseudoleptochelia include having the carpus of pereopod 1 as long as the merus (nearly twice as long in Pseudoleptochelia ), and the carpi of pereopods 4 to 6 attached slightly dorsally to the meri (synaxial in Pseudoleptochelia ). The elongate pereonites 4 and 5 in the female are unusual for the family (all pereonites wider than long in Pseudoleptochelia , although elongate pereonites are present in Parakonarus oregmus Bamber, 2013 ), and are presumably an adaptation to an interstitial mode of life in the fine sands in which the species was living.

The absence of an inner seta on the pleopod endopod and basis is a feature present in the new leptocheliin Nuberis areolaticola sp. nov. described below, suggesting the possibility that this may be somehow related to an interstitial mode of life, rather than being phylogenetically significant. Conversely, while that leptocheliin also has pointed distal spines on the maxilliped endite, this feature is found in Catenarius , which was not thought to be interstitial (but see below). A full resolution of the relationships of Brunarus would be enabled by the discovery of the male, as yet unknown.