Alboscia itapuensis, Araujo & Quadros, 2005

Araujo, Paula Beatriz & Quadros, Aline Ferreira, 2005, A new species of Alboscia Schultz, 1995 (Crustacea: Isopoda: Oniscidea: Philosciidae) from Brazil, Zootaxa 1018 (1), pp. 55-60: 56-57

publication ID

http://doi.org/ 10.11646/zootaxa.1018.1.4

publication LSID

lsid:zoobank.org:pub:3C1B4146-4E4B-405A-B2E4-2C4E1578ACE6

persistent identifier

http://treatment.plazi.org/id/351787EA-FF9B-FFC9-B71F-FCE903DDF88F

treatment provided by

Felipe

scientific name

Alboscia itapuensis
status

n. sp.

Alboscia itapuensis   n. sp. ( Figs. 1–20 View FIGURES 1–7 View FIGURES 8–12 View FIGURES 13–20 )

Material: Holotype: ♂, BRAZIL, Rio Grande do Sul, Viamão, 30°34’S, 51°05’W, Parque Estadual de Itapuã, Trilha da Onça , sifting soil, 23 June 2004 ( MZUSP 16252 View Materials ) GoogleMaps   . Paratypes, same locality as holotype, 24 August 2004, 2 ♀ ( UFRGS 3791 View Materials ) GoogleMaps   ; same locality, 21 August 2004, 1 ♂ and 1 ♀ ( UFRGS 3792 View Materials ) GoogleMaps   .

Description: Maximum dimensions: male 2.0 x 0.5 mm; ovigerous female 2.8 x 0.9 mm. Body lacking pigment; eyes absent. Body surface smooth with long setae. Conspicuous noduli laterales (coordinates b/c and d/c as in Fig. 2 View FIGURES 1–7 ; “d” shows similar distance in all pereonites). Pleon slightly retracted from pereon ( Fig. 1 View FIGURES 1–7 ). Epimera of pleonites not visible in dorsal view. Pleotelson with rounded apex and sinuous lateral margins, bordered by long setae, about 4 times as wide as long ( Fig. 8 View FIGURES 8–12 ).

Antennule slender with distal article bearing 1 sub­apical and 2 apical aesthetascs ( Fig. 3 View FIGURES 1–7 ). Antenna, when extended posteriorly reaches pereonite II; distal flagellar article longest, bearing 2 aesthetascs; apical organ as long as the first flagellar article ( Fig. 4 View FIGURES 1–7 ). Mandibles with 1 and 2 penicils on the right and left mandibles respectively. Inner lobe of the maxillule with rounded apical margin, bearing two penicils; outer lobe with 4+5 teeth (3 pectinate and 1 bifid) ( Fig. 5 View FIGURES 1–7 ). Maxilla covered with short hair­like setae on the internal lobe ( Fig. 6 View FIGURES 1–7 ). Palp of maxilliped conical, without apical setal tuft; medial tufts composed of 2 and 1 seta; endite with a medial seta and one spine on curved margin ( Fig. 7 View FIGURES 1–7 ). Pereopods with spoon­like dactylar organ and 2 ungual setae (except in pereopod 1, in both male and female); no sexual dimorphism on pereopods ( Figs. 9­12 View FIGURES 8–12 ). Exopod and endopod of the uropod with a single apical seta ( Fig. 8 View FIGURES 8–12 ).

Genital papilla with ventral shield pyriform and rectangular spatula ( Fig. 13 View FIGURES 13–20 ). Pleopod 1 exopod oval and without setae ( Fig.14 View FIGURES 13–20 ); endopod moderately curved apically with one small apical spine ( Fig. 15 View FIGURES 13–20 ). Pleopod 2 exopod subtriangular, with 3 setae on the external lateral margin ( Fig. 16 View FIGURES 13–20 ); endopod with slender distal half and small medial setae ( Fig. 17 View FIGURES 13–20 ). Pleopods 3–5 with exopods presenting posterolateral margin with long setae ( Figs. 18–20 View FIGURES 13–20 ).

Etymology: The specific name refers to the type locality: Itapuã.

Remarks: Alboscia itapuensis   n. sp. resembles A. silveirensis   with respect to the length of flagellar articles and apical organ of the antenna, maxillule with three pectinate teeth and one bifid, presence of two ungual setae as well as the shape of the exopod of pleopod 1 of the male. The new species can be readily distinguished from A. elongata   , A. silveirensis   and A. ornata   by the absence of eyes, the pattern of the aesthetascs on the antennule, the telson being posteriorly rounded and four times as wide as long and by the spoon­like dactylar organ. This is the first known eyeless species of Alboscia   .

Alboscia itapuensis   n. sp. is an endogean species found under the litter layer, in soft soil, at depth of about 2 cm.

All species of Alboscia   , including A. itapuensis   n. sp., have a depigmented body and either lack eyes or have a reduced number (1–3) of ommatidia.