Dendrocephalus xikrini Rabet & Bozelli, 2018

Rabet, Nicolas, Lacau, Sébastien & Bozelli, Reinaldo L., 2018, Richness of Dendrocephalus (Branchiopoda, Anostraca) in Brazil with the description of two new species, European Journal of Taxonomy 478, pp. 1-20 : 7-12

publication ID	https://doi.org/ 10.5852/ejt.2018.478
publication LSID	lsid:zoobank.org:pub:644EB0C5-C63E-4F52-A663-64CCF3A48AFF
DOI	https://doi.org/10.5281/zenodo.3846035
persistent identifier	https://treatment.plazi.org/id/D01C2A1B-75C2-4297-B1D3-B8B2564EB672
taxon LSID	lsid:zoobank.org:act:D01C2A1B-75C2-4297-B1D3-B8B2564EB672
treatment provided by	Valdenar
scientific name	Dendrocephalus xikrini Rabet & Bozelli
status	sp. nov.

Treatment

Dendrocephalus xikrini Rabet & Bozelli View in CoL sp. nov.

urn:lsid:zoobank.org:act:D01C2A1B-75C2-4297-B1D3-B8B2564EB672

Figs 1 View Fig , 5–6 View Fig View Fig , 7I View Fig

Etymology

Named in honour of the Xikrin, a subgroup of indigenous people from the Kayapó tribes living in the area of the Serra dos Carajás.

Material examined

Holotype

BRAZIL: mature Ƌ, total length 15.0 mm, cercopods 2.8 mm, Serra dos Carajás, Pará, 6°21′06.27″ S, 50°23′43.66″ W, pool S11-BC in an Amazonian savannah (Canga deposits), 25 Nov. 2013, R. Bozelli

GoogleMaps

leg. ( MNRJ 2973). In the same study period, approximately 30 phytoplankton species, 30 zooplankton species and 15 aquatic macrophyte species were recorded in the pool, but no fish were observed.

Allotype

BRAZIL: mature ♀, total length 12.8 mm, brood pouch 2.9 mm reaching the extremity of the 6 th abdominal segment (including genital segments), cercopods 2.7 mm, same collecting data as for holotype ( MNRJ 2974 View Materials ). GoogleMaps

Paratypes

BRAZIL: 8 ƋƋ, same collecting data as for holotype, total length 15.1 to 16.5 mm, mean = 15.75 ± 0.58 mm, cercopods 2.3 to 2.7 mm, mean = 2.56 ± 0.15 mm; 1 ♀, same collecting data as for holotype, length 13.5 mm, brood pouch 3 mm, cercopods 3 mm (2 ƋƋ, 1 ♀ MNHN (MNHN-IU-2016-3559); 2 ƋƋ in MNRJ ( MNRJ 2975)). Other specimens are kept in personal collections of NR and RLB.

Type locality ( Figs 1 View Fig , 7I View Fig )

Pool S11-BC is the smallest (average area of 0.13 ha) among the previously studied lentic aquatic environments in the Serra dos Carajás inside the Carajás National Forest. Although very shallow (0.10 to 0.25 m) during our sporadic explorations from 2005–2013, the pool was never found completely dry, and during this period, its volume ranged from 56 to 140 m 3. Nevertheless, it is a temporary pool because it was possible to verify that the pool dried up in Google Earth images from August 2006. The electrical conductivity of the water varies between 4 and 64 μS/cm and pH varied between 4.89 and 5.63. The recorded turbidity values were between 1 and 64 NTU, but the water was always completely transparent.

Description

Male

Eye pedunculate, ovoid in lateral view with a prominent spine. Length of the spine relative to that of the eye between 10 and 20% ( Fig. 5A View Fig ). Antenna-like outgrowth slender, lying between the first antennae and second antennae. Second antennae with proximal antennomeres fused basally on the anterior of the head. Proximal antennomere mediodistally bearing a stout digitiform process ornamented with setae. Distal antennomere weakly sclerotized, evenly curved medially, and ornamented on the medial surface with scaliform transverse ridges; terminus acute. Frontal appendages with anterior margin of the base of the arms with three or four spines ( Fig. 5B View Fig ). Arms from the base to the terminal branches with spines ( Fig. 5B View Fig ). Frontal appendage complex with one ventral branch (1V) and three terminal branches (2V, 2D, and 2A). The terminal appendage in the medial position called branch 2A with a podiform apex and one well-developed cell-pad on the first third of the branch. A long spiniform process is present basally ( Fig. 5C View Fig ). Ventral branch called branch 1V with two sub-branches. Sub-branch I (most proximal) with one row of spines on the medial side with an acute extremity ( Fig. 5D View Fig ). Sub-branch II ¾ of the length of sub-branch I and with a row of short spines on the medial side with an acute extremity ( Fig. 5D View Fig ). Terminal ventral branch called branch 2V cylindrical and ending in a cluster of four to five cell-pads on a bulge and four rows of cell pads on the medial surface ( Fig. 5E View Fig ). Terminal branch in the dorsal position called branch 2D subdivided into three sub-branches. Sub-branch I (most proximal) with a row of short spines on the medial side and with three or four long spines (length of which is more than twice the diameter of the sub-branch) in the first half of the sub-branch ( Fig. 6A View Fig ). Sub-branch II longer than half of sub-branch I, with a row of small spines on the medial side and with two long spines (the length of which is greater than or equal to the diameter of the sub-branch) in the first half and half the length of the sub-branch ( Fig. 6A View Fig ). Sub-branch III slightly shorter than sub-branch I (80%) with twice the average diameter, proximally cylindrical and distally flattened and bearing a large spiniform process; distal flattened portion with two or three long spines (equalling the width of the sub-branch) on the posterolateral side ( Fig. 6A View Fig ). Endopodite of the first pair of limbs with a reduced basolateral lobe sharing small spines that form a row extending to the distal corner ( Fig. 6B View Fig ). Endopodite of the second pair of limbs with a border sharing large spines ( Fig. 6C View Fig ). Endopodite of the third pair of limbs similar to the second with slightly larger spines ( Fig. 6D View Fig ). No differentiation was observed in the fourth pair of limbs ( Fig. 6E View Fig ). Abdominal segments smooth. Cercopods margined with plumose setae.