Dendrocephalus aranai Rabet & Lacau & Bozelli 2018, sp. nov.
Creators: name: Rabet, Nicolas
name: Lacau, Sébastien
name: Bozelli, Reinaldo L.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Branchiopoda
Anostraca
Thamnocephalidae
Dendrocephalus
Dendrocephalus aranai

description: Dendrocephalus aranai Rabet & Lacau sp. nov.
urn:lsid:zoobank.org:act: 222FFFBE-BD26-4191-BC3E-A5D3864B07B4
Figs 1–3, 7H
Etymology
‘Aranã’ is the Portuguese (Brazil) name for an indigenous Brazilian tribe in the ‘Vale do Jequitinhonha’ region, which is near the type locality. Today, their population has been nearly extinguished, so the new species is named in honour of these people.
Material examined
Holotype
BRAZIL: mature Ƌ, total length 24.1 mm, cercopods 4.2 mm, Minas Gerais, Jequitinhonha, 16°25′10.47″ S, 40°57′4.46″ W, temporary pool no 4, 17 Jan. 2009, T. Chaves leg. (MNRJ 27970) (Fig. 7H).
Allotype
BRAZIL: mature ♀, total length 21.7 mm, brood pouch 5.5 mm reaching the 5 th abdominal segment, cercopods 4.1 mm, same collecting data as for holotype (MNRJ 27971).
Paratypes
BRAZIL: 8 ƋƋ, total length 14.5 to 25.1 mm, mean = 19.55 ± 2.95 mm, cercopods 2.5 to 4.2 mm, mean = 3.28 ± 0.5 mm, same collecting data as for holotype; 4 ♀♀, total length 17 to 20.6 mm, mean = 18.33 ± 1.58 mm, brood pouch 4 to 4.7 mm, mean = 4.43 ± 0.31 mm, cercopods 3.1 to 3.6 mm, mean = 3.25 ± 0.31 mm, same collecting data as for holotype (2 ƋƋ, 2 ♀♀ in MNHN (MNHN-IU-2016-3558); 2 ƋƋ, 1 ♀ in MNRJ (MNRJ 27972)). Other specimens kept in NR’s personal collection.
Type locality
The pool (Fig.7H) is in a well-lit location at a climatic crossroads with influences from the Atlantic Forest, Cerrado and lesser Caatinga. The other large branchiopods sampled in the same ponds are Eulimnadia colombiensis Roessler, 1989.
Description
Male
Eye pedunculate, ovoid in lateral view with a prominent spine. Length of the spine relative to the eye between 10 and 20% (Fig. 2A). Antenna-like outgrowth slender, lying between 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. 2B). Arms from the base to the terminal branches with spines (Fig. 2B). Frontal appendage complex with one ventral branch (1V) and three terminal branches (2V, 2D, 2A). The terminal appendage in the medial position, called branch 2A, with a podiform apex and one long cell pad present proximally, parallel to the main axis, and a more lateral structure resembling a ‘cell pad’ on a bulge. A long spiniform process is present basally (Fig. 2C). A ventral branch called branch 1V with two sub-branches. Sub-branch I (most proximal) with one row of spines on the medial side, a swollen extremity with five spines posteriorly oriented and three to five small cell pads anteriorly oriented. Branch 1V distally ramified in two sub-branches, both with a longitudinal row of medial spines (Fig. 2D). 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. 2D). Terminal and ventral branch called branch 2V cylindrical and ending in a cluster of five to seven cell-pads on a bulge, with two rows of cell pads and a long cell pad on the medial surface (Fig. 2E). Terminal branch in the dorsal position called branch 2D is subdivided into three sub-branches. Sub-branch I (most proximal) with a row of short spines on the medial side and with three long spines (length more than four times the diameter of the sub-branch) (Fig. 3A). Sub-branch II shorter than half of sub-branch I with three long spines (gradually decreasing in size towards the apical part from three times the length to twice the length of the diameter of the sub-branch) (Fig. 3A). Subbranch III ¾ shorter and five times wider than sub-branch I, bearing two large spiniform processes, and with a distally flattened portion with two spines on the posterolateral side (Fig. 3A). Endopodite of the first pair of thoracopods with a basolateral lobe ending in one to four smooth spines and a distolateral non-prominent border with two spines (Fig. 3B). Endopodites of limb 2 with a prominent distolateral border ornamented with 12–13 spines and a strong, small extension with two small spines (Fig. 3C). Endopodites of limb 3 with a prominent distolateral border ornamented with 12–13 spines (Fig. 3D). Endopodites of limb 4 with only eight small spines on the distolateral corner (Fig. 3E). No differentiation was observed in the fourth limbs (Fig. 3E). Abdominal segments smooth. Cercopods margined with plumose setae.
Female
Typical of the genus.
Resting egg
Subspherical with broad pentagonal or quadragonal facies. Diameter ranging from 222 to 247 mm, mean = 236.1 ± 7.79 mm (n = 8, diameter based on three measurements for each egg). Depression number ranging from 7 to 8, mean = 7.88 ± 0.35 (n = 8).
Distribution
This species is known from several pools in the area next to the locus typicus.
description: Published as part of Rabet, Nicolas, Lacau, Sébastien & Bozelli, Reinaldo L., 2018, Richness of Dendrocephalus (Branchiopoda, Anostraca) in Brazil with the description of two new species, pp. 1-20 in European Journal of Taxonomy 478 on pages 3-7, DOI: 10.5852/ejt.2018.478, http://zenodo.org/record/3825236