Oxossioniscus akoko, Campos-Filho & Teixeira Lisboa & Monticelli Cardoso, 2018

Campos-Filho, Ivanklin Soares, Teixeira Lisboa, Jonathas & Monticelli Cardoso, Giovanna, 2018, A new genus and two new species of Pudeoniscidae Lemos de Castro 1973 (Crustacea: Isopoda: Oniscidea) from Brazil, Journal of Natural History (J. Nat. Hist.) 52 (7 - 8), pp. 457-482 : 473-479

Oxossioniscus akoko sp. nov.

( Figures 10 – 13 , 14 (d))

Pudeoniscus obscurus ; Lisboa et al. 2013:394, figure 1D.

Type material

Holotype Bahia: 1 ♂ ( MZUSP 35006 ), Ituberá-Iguapiuna, 18 – 22/VIII/2010, leg. S. Varjão. Paratypes Bahia: 3 ♂♂, 10 ♀♀ ( MZUSP 35007 ), 2 ♂♂, 2 ♀♀ ( MZUF 9660 ), same data as holotype; 3 ♂♂, 1 ♀ ( MZUSP 35008 ), 2 ♂♂, 1 ♀ ( MZUF 9661 ), Ilhéus, UESC, 30/VII/2013, leg . J .T . Lisboa ; 3 ♂♂, 3 ♀♀ ( MNRJ 27686 ), Ilhéus, Campus do Centro de Pesquisas do Cacau ( CEPEC-CEPLAC), - 14.757777°S, - 39.237777°W, IX/2007, leg . P .P . Santos , in termite nest of Nasutitermes sp .

Aditional material

Bahia: 2 juveniles ( UFRGS 4545 ), Ilhéus, CEPLAC, 30 May 2008, leg . J .T . Lisboa , in leaf litter of Theobroma cacao ; 2 ♂♂, 4 ♀♀ ( UFRGS 5680 ), Ituberá, Reseva Michelin, Sep . 2009, leg . M .C.L . Peres ; 2 ♂♂, 4 ♀♀ ( UFRGS 5738 ), Ituberá, Reseva Michelin, May 2009, leg . M .C.L . Peres ; 1 ♀ ( UFRGS 5739 ), Ituberá, Reserva Michelin, 30 October 2009, leg . M .C.L . Peres; 1 ♀ ( UFRGS 5823 ), Travessão - 14.141944°S, - 39.291889°W, 18 September 2013, leg . I .S . Campos-Filho and J .T . Lisboa; 1 ♀ ( UFRGS 5819 ), Itabuna , - 14.718888°S, - 39.354166°W, 18 April 2013, leg . I .S . Campos-Filho and J .T. Lisboa.

Description

Maximum body length: ♂ 13 mm, ♀ 14 mm. Habitus in lateral view as in Figure 10 (a). Colour brown, cephalon with irregular unpigmented spots; antenna with fifth article of peduncle and first article of flagellum unpigmented; pereonites 1 – 7 with one large unpigmented spot on median portion and large unpigmented spots on paramedian areas, epimera slightly pigmented; pleon and telson strongly pigmented, pleonites 1 – 5 with three slightly unpigmented spots; uropods slightly pigmented. Pereonites 1 – 7 with longitudinal dorsal grooves from noduli laterales to posterior margins, gradually decreasing in length, with verruca-like cuticle ( Figures 10 (a), 13(b)). Dorsum smooth covered with triangular scale-setae ( Figures 10 (b), 13 (b)). Cephalon ( Figures 10 (c, d), 13(a)) with lateral lobes bent upwards, triangular frontal shield straight on upper margin and concave at lateral sides; eyes consisting of 20 ommatidia. Noduli laterales short inserted on anterior portion of dorsal furrow ( Figures 10 (a), 13(b)). Pereonite 1 with dorsolateral furrow reduced with verruca-like cuticle, and with transverse sinuous depression ( Figures 10 (a, c, d), 13(b)); pereonites 1 – 3 with ventral lobes slightly developed ( Figure 10 (e)). Pleon ( Figure 10 (f, g)) with neopleura 5 not surpassing distal margin of telson; telson with dorsal depression twice as long as wide, proximal portion almost three times as wide as distal portion, lateral sides concave. Antennula ( Figure 10 (h)) with proximal and distal articles subequal in length, distal article with four aesthetascs inserted in one set plus apical pair. Antenna ( Figures 10 (i), 13(c)) when extended posteriorly reaching anterior margin of pereonite 2, distal article of peduncle about twice as long as flagellum; second article of flagellum twice as long as distal article, distal article bearing two lateral sets of aesthetascs. Mandible with molar penicil of about five branches, left mandible ( Figure 11 (a)) with 2 + 1 penicils, right mandible ( Figure 11 (b)) with 1 + 1 penicils. Maxillula ( Figure 11 (c)) inner endite bearing two penicils, distal margin with small lateral tip; outer endite of 4 + 6 teeth, outer set with accessory tooth and inner set with five cleft teeth at apex. Maxilla ( Figure 11 (d)) inner lobe rounded covered with thick setae, outer lobe slightly rounded, three times as wide as inner lobe covered with thin setae. Maxilliped ( Figure 11 (e)) palp with two distinct setae on proximal article; endite subrectangular, densely covered with thin setae on distal portion, median seta not surpassing distal margin, distal outer margin with one short hook-like seta. Pereopods 1 – 7 stout, carpus 1 with antennal grooming brush longitudinal and distal seta serrate at apex; dactylus of two claws, inner claw reaching distal margin of outer claw; ungual seta not surpassing distal margin of outer claw, dactylar seta stout with apex bifid bearing many thin setae. Uropod ( Figure 12 (a)) endopod as long as exopod, exopod grooved on outer margin. Respiratory structures ( Figure 13 (d, e)) as in diagnosis.

Male: Pereopods 1 ( Figure 12 (b)) merus and carpus with sparse setae on sternal margins, carpus more setose; pereopod 7 ( Figure 12 (c)) ischium triangular without any apparent dimorphism. Genital papilla as in Figure 12 (d). Pleopod 1 – 5 exopods bearing many thin setae along inner and outer margins. Pleopod 1 ( Figure 12 (e)) exopod triangular, wider than long, inner margin slightly rounded, distal margin rounded, outer margin almost straight; endopod about three times as long as exopod, inner distal portion bearing three setae. Pleopod 2 ( Figure 12 (f)) exopod triangular, outer margin concave; endopod stout and longer than exopod. Pleopod 3 and 4 exopods as Figure 12 (g) and (h), respectively. Pleopod 5 exopod ( Figure 12 (i)) rhomboid, inner margin slightly rounded and distal margin straight.

Etymology

The new species is named after the Akoko leaves ( Newbouldia laevis ), which represent Oxóssi. The word has its origins in the Ióruba language, in which akòko means money and child prosperity.

Remarks

Oxossioniscus akoko sp. nov. is included in the new genus based on the presence of polyspiracular pleopodal lungs. The reduced dorsolateral furrow and the presence of longitudinal dorsal grooves on pereonites 1 – 7 may be autapomorphic characters of the species. Oxossioniscus akoko sp. nov. can also differ from O. pataxo sp. nov. by the dactylar seta bifid at apex, the shape of male pleopod 1 exopod, and the presence of pleopodal lung on pleopod 5 exopod.

Figures

Figure 10. Oxossioniscus akoko sp. nov., ♂ paratype MZUF 9660: (a) Habitus, lateral view; (b) Scaleseta; (c) Cephalon, antennae and pereonites 1 and 2, frontal view; (d) Cephalon, antenna and pereonite 1, dorsal view; (e) Pereonites 1–3, ventral view; (f) Pleonites 4 and 5, telson and uropods, dorsal view; (g) Pleonites 4 and 5, telson and uropods, ventral view; (h) Antennula; (i) Antenna.

Figure 11. Oxossioniscus akoko sp. nov., ♂ paratype MZUF 9660: (a) Left mandible; (b) Right mandible; (c) Maxillula; (d) Maxilla; (e) Maxilliped.

Figure 12. Oxossioniscus akoko sp. nov., ♂ paratype MZUF 9660: (a) Uropod; (b) Pereopod 1; (c) pereopod 7; (d) Genital papilla; (e) Pleopod 1; (f) Pleopod 2; (g) Pleopod 3 exopod; (h) Pleopod 4 exopod; (i) Pleopod 5 exopod.

Figure 13. Oxossioniscus akoko sp. nov. ♂ paratype UFRGS 5680. (a) Cephalon, frontal view; (b) Pereonite 1 epimeron, arrows showing the nodulus lateralis, verruca-like scales, and triangular scaleseta; (c) Antennal flagellum; (d) Pleopod 1 exopod; (e) Pleopod 4 exopod. Scale bars: (a, b) 200 µm; (c–e) 100 µm; (b) (enlarged boxes) 100 µm (upper) and 20 µm; (d, e) (enlarged boxes) 10 µm.

Figure 14. Distribution map of Pudeoniscus Vandel, 1963: (a) Pudeoniscus birabeni Vandel, 1963; (b) Pudeoniscus obscurus Lemos de Castro, 1973; (c) Oxossioniscus pataxo sp. nov.; (d) Oxossioniscus akoko sp. nov. Abbreviations: BA, Bahia; DF, Distrito Federal; ES, Espírito Santo; GO, Goiás; MG, Minas Gerais; PR, Paraná; RJ, Rio de Janeiro; SC, Santa Catarina; SP, São Paulo.