Amazoniscus schmidti Campos-Filho, Montesanto & Taiti, 2017

Campos-Filho, Ivanklin Soares, Montesanto, Giuseppe, Araujo, Paula Beatriz & Taiti, Stefano, 2017, New species and new records of terrestrial isopods (Crustacea, Isopoda, Oniscidea) from Brazil, Iheringia, Série Zoologia (e 2017034) 107, pp. 1-30 : 12-18

Amazoniscus schmidti Campos-Filho, Montesanto & Taiti sp. nov.

( Figs 51-73 )

http://zoobank.org/ urn:lsid:zoobank.org:act:4BCD8697-F127-4546-8084-8E9870AB2EE2

Amazoniscus arlei ; SCHMIDT, 2007: 64 , figs 192-195 (partim: specimens from Leopoldina, state of Minas Gerais).

Type material. BRAZIL, Minas Gerais: Holotype ♂, Belo Horizonte, undated, H. A. Pinto col. (MZUSP 35112) . Paratypes: 3♀, same data as holotype (MZUSP 35113) .

Description. Maximum body length: ♂ 8.5 mm, ♀ 9.5 mm. Color brown; cephalon with irregular unpigmented spots; antenna unpigmented; pereon more pigmented on median portion and epimera, unpigmented spots on paramedian region; pleon and uropods darker, pleonites 1-3 and telson with two unpigmented spots. Body convex, exoantennal conglobation ( Fig. 51 ). Dorsum smooth with some scattered triangular scale-setae ( Fig. 52 ); one line of noduli laterales per side, more or less at same distance from lateral margins and close to posterior margins of pereonites ( Fig. 51 ); no visible gland pores. Cephalon ( Figs 53-55 ) with frontal shield bent backwards over vertex, frontal margin broadly rounded; eyes of 13-15 ommatidia. Pereonite 1 without schisma or ventral lobes; pereonites 1-4 with posterior margin straight, 5-7 gradually more concave ( Figs 51, 55 ). Pleon ( Figs 56, 57 ) continuous with pereon, epimera 3–5 well developed, directed backwards with acute apex. Telson ( Fig. 56 ) triangular, short, twice as broad as long, with slightly concave sides, rounded apex. Antennula ( Fig. 58 ) of three articles, third article about three times as long as second, bearing five rows of two aesthetascs each and apically pointed. Antenna ( Fig. 59 ) reaching posterior margin of second pereonite when extended back, fifth article of peduncle twice as long as flagellum, flagellum with two articles subequal in length, distal article with two rows of two aesthetascs each, apical organ as long as second article of flagellum with simple and short free sensilla. Mandible ( Figs 60, 61 ) with molar penicil dichotomized, consisting of about 10 branches, left mandible with 2+1 penicils, right with 1+1 penicils. Maxillula ( Fig. 62 ) with inner branch bearing two subequal penicils, distal margin rounded with very short posterior point; outer branch with 4+6 (four cleft) teeth plus accessory tooth and slender seta. Maxilla ( Fig. 63 ) outer lobe about twice as broad as medial lobe, distal margin rounded, covered with thin setae; inner lobe rounded, covered with thick setae. Maxilliped ( Fig. 64 ) with basis rectangular bearing sparse scale-setae, distal margin with fringe of thin setae; endite rectangular, distal margin slightly rounded with one triangular seta and short penicil; palp with three tufts of setae, proximal article with one inner seta. Pereopods with short inner claw, ungual seta long and simple, long dactylar seta reaching tip of outer claw. Pleopods 1 and 2 with respiratory areas. Uropod ( Fig. 65 ) with insertion of endopod and exopod at different levels, protopod flattened and enlarged, endopod twice as long as exopod.

Male: cephalon ( Figs 53, 54 ) with rounded dorsal depression on vertex bearing one triangular structure near frontal shield. Pereopod 1 ( Fig. 66 ) merus and carpus with sternal margin covered with short scales and sparse strong setae. Pereopod 7 ( Fig. 67 ) ischium elongated, sternal margin concave; merus with medial ridge bearing setae; carpus twice as long as merus. Genital papilla as in Fig. 68 . Pleopod 1 ( Fig. 69 ) exopod with very sinuous outer margin, distal part triangular; endopod longer than exopod, bearing small setae along median margin, distal portion slightly depressed subapically bearing line of small setae. Pleopod 2 ( Fig. 70 ) exopod outer margin strongly sinuous bearing one small seta; endopod as long as exopod. Pleopod 3 and 4 exopods ( Figs 71, 72 ) subrectangular bearing three small setae each, inner and outer margins fringed with thin setae. Pleopod 5 exopod ( Fig. 73 ) triangular, distal part narrower and acute, outer margin sinuous with one small seta, inner and outer margins fringed with thin setae.

Etymology. The new species is named after Dr. Christian Schmidt, for his valuable contribution on the taxonomy of the family Scleropactidae .

Remarks. SCHMIDT (2007), in his study of the Neotropical Scleropactidae , redefined the genus Amazoniscus and redescribed A. arlei based on the type material from the north of Brazil in the states of Amapá and Pará. The author extended the records of this species to the states of Minas Gerais and Rio de Janeiro (southeastern Brazil); the material is deposited in the collection of MNRJ. Based on the illustrations provided by the author, it is possible to observe clear differences between north- and southeastern specimens. The northern specimens show the male pereopod 7 ischium triangular shaped, slightly concave on sternal margin (vs. rounded and strongly concave), the dactylar organ with setose apex (vs. simple), the male pleopod 1 exopod with the distal portion acute (vs. triangular), the male pleopod 1 endopod with distal inner portion bent inwards (vs. depressed and slightly bent outwards). Based on the characters of the male pereopods 1, 2 and 7 and pleopods 1 and 2, we assume that the species illustrated by the author from the state of Minas Gerais, corresponds to the new species described here. The material from the state of Rio de Janeiro needs to be re-examined to confirm if it belongs to Amazoniscus schmidti sp. nov..

Amazoniscus schmidti sp. nov. is similar to A. arlei in the falciform shape of the male pleopod 1 exopod, but it is easily distinguished by the male cephalon with dorsal rounded depression and triangular lobe, male pereopod 1 merus and carpus with slightly sparse setae on sternal margin, carpus 1 with large antennal grooming brush, pereopod 7 ischium long, dorsal margin rounded and strongly concave on sternal margin, dactylar organ simple without hairy appearance, the male pleopod 1 exopod with triangular distal portion, and the male pleopod 1 endopod with distal inner depression and directed outwards.

Circoniscus Pearse, 1917 Circoniscus bezzii Arcangeli, 1931

Circoniscus bezzii ARCANGELI, 1931:115 , plate II; VAN NAME, 1936:311, fig. 184; VILELA et al., 1971:185; SOUZA & LEMOS DE CASTRO, 1991:50, figs 23-44; SCHULTZ, 1995:417, fig. 12J-M; SOUZA-KURY, 1998:666; LEISTIKOW & WÄGELE, 1999:38; SCHMALFUSS, 2003:81; SCHMIDT, 2007:72 , figs 224-229; CAMPOS-FILHO et al., 2014:396 , 0.

Material examined. BRAZIL, Minas Gerais: 5♀, 1 juvenile, Serra da Canastra , Casca D’Anta, 20°18’47”S, 46°31’47”W, at 861 meters, 13.VI.2013, riparian forest (UFRGS 5720) ; ♀, SÃo JoÃo Batista da Glória , 20°36’12”S, 46°25’16”W, 13.VI.2013, I. S. Campos-Filho & G. M. Cardoso col., Cerrado biome (UFRGS 5718) ; ♀, Carmo do Rio Claro , 20°58’05”S, 46°18’43”W, 12.VI.2013, I. S. Campos-Filho & G. M. Cardoso col. (UFRGS 5715) ; 2♀, Carmo do Rio Claro , 11.VI.2013, I. S. Campos-Filho & G. M. Cardoso col. (UFRGS 5712) ; ♀, Varginha , 21°33’21”S, 45°26’12”W, 15.VI.2013, I. S. Campos-Filho & G. M. Cardoso col. (UFRGS 5725) .

Previous Brazilian records. Minas Gerais: Alfenas ( SOUZA & LEMOS DE CASTRO, 1991); Presidente Olegário ( CAMPOS-FILHO et al., 2014). EspÍrito Santo: Linhares and Santa Tereza ( SOUZA & LEMOS DE CASTRO, 1991). Mato Grosso: Carandasinho ( ARCANGELI, 1931; SOUZA & LEMOS DE CASTRO, 1991). SÃo Paulo:Amparo, Capivari, Descalvado, Mogi-GuassÚ, Nova Europa, Pirassununga, SÃo Carlos, Tabatinga and Urucai ( SOUZA & LEMOS DE CASTRO, 1991).

Distribution. This species is recorded from Brazil (states of Minas Gerais, EspÍrito Santo, Mato Grosso and SÃo Paulo) and Paraguay.

Pudeoniscidae Pudeoniscus Vandel, 1963 Pudeoniscus birabeni Vandel, 1963

Pudeoniscus birabeni VANDEL, 1963:91 , figs 16-19; LEMOS DE CASTRO, 1973:3; SOUZA-KURY, 1998:665; LEISTIKOW & WÄGELE, 1999:43; SCHMALFUSS, 2003:226; SCHMIDT, 2003:79, figs 100-103; LISBOA et al., 2013:395.

Material examined. Bahia: ♂, Salvador, BaÍa de Aratu, IX.2006, J. T. Lisboa col. (UFRGS 4231); ♀, IlhÉus, UESC, 25.VIII.2013, J. T. Lisboa col. (MZUF 9649) .

Previous Brazilian records. Bahia: IlhÉus ( LISBOA et al., 2013). Rio de Janeiro: Pico de Tijuca, Rio de Janeiro ( VANDEL, 1963; SCHMIDT, 2003); Angra dos Reis ( Ilha Grande), Mangaratiba (Ribeira, RubiÃo, Muriqui) and Rio de Janeiro (AÇude da SolidÃo, Floresta da Tijuca, Furnas da Tijuca, Pedra do Conde, Represa dos Ciganos) ( LEMOS DE CASTRO, 1973). SÃo Paulo: Estrada Velha Santos-SÃo Paulo, Piassaguera and Santos ( LEMOS DE CASTRO, 1973).

Distribution. This species is recorded from the states of Bahia, Rio de Janeiro and SÃo Paulo.

Platyarthridae

Remarks. At present the family Platyarthridae includes more than 110 species in nine genera, mainly distributed in tropical areas. The family is most probably paraphyletic ( SCHMIDT, 2003). Recently, the new family Paraplatyarthridae Javidkar & King, 2015 (Crinocheta) was erected to accommodate the new genus and the new species Paraplatyarthrus subterraneus Javidkar & King, 2015 from Laverton Downs, Windarra calcrete, Eastern Murchison region, Western Australia ( JAVIDKAR et al., 2015), and an unnamed and undescribed genus from southern Brazil. These two species are morphologically very similar to the genus Trichorhina , presently included in the Platyarthridae . Paraplatyarthridae is defined by dorsal surface with fan-like scale setae, antenna ventrally with leaf-like setae and furrow with hair-like capillary setae, part of water conduction system (WCS), flagellum of two articles, cephalon with postfrons and profons fused, maxillula outer endite with 4+4/5 teeth (one shorter). The family was erected with an integrative taxonomy approach, using molecular and morphological data, and it was recovered as monophyletic. At the moment, the morphological characters proposed by the authors to define the family do not show any synapomorphy, which allows its recognition. This also occurrs in phylogenetical analyses of other genera of Oniscidea (see SCHMIDT 2002, 2003). The dorsal fan-shaped scale-setae are shared with other genera and families of Crinocheta, for example, some members of Philosciidae ( Caraiboscia Vandel, 1968 , Metaprosekia Leistikow, 2000 ) (see LEISTIKOW, 2000; CAMPOS-FILHO et al., 2014), members of Dubioniscidae Schultz, 1995 (see CARDOSO et al., 2016), members of Spelaeoniscidae Vandel, 1948 (see SCHMIDT, 2003), and the genus Chileoniscus Taiti, Ferrara & Schmalfuss, 1986 (incertae sedis) (see SCHMIDT, 2007). This structure seems to be related with an endogean way of life and it has an anti-adhesive function ( SCHMALFUSS, 1978). Most probably this structure evolved by convergence or parallelism since it occurs in different families of Crinocheta ( SCHMIDT, 2002). The furrow bearing setae on the antenna belongs to the WCS ( HOESE, 1981; SCHMALFUSS, 1998), and it is present in many different Crinocheta families (see SCHMIDT, 2003). The fused postfrons and profons on the cephalon, together with the 4+4/5 teeth on the maxillula outer endite are present in many genera of Crinocheta (LEISTIKOW, 2001; SCHMIDT, 2003, 2007). Recently, JAVIDKAR et al. (2017) added new diagnostic characters to the family, such as dorsal surface smooth, one line of noduli laterales per side on pereonites 1-6 and pereonite 7 with two noduli laterales per side. The presence of two noduli laterales per side on pereonite 7 is also observed in Trichorhina tomentosa ( Budde-Lund, 1893) , type species of the genus (see SCHMIDT, 2003), as well as in members of Philosciidae , i. e. Barnardoscia Taiti & Ferrara, 1982 , Anchiphiloscia Taiti & Ferrara, 1980 , and Benthanops Barnard, 1932 , Hawaiioscia Schultz, 1973 (see TAITI & FERRARA, 1987). In conclusion, if the family Paraplatyartridae migth be well characterized molecularly, it does not seem to be so from a morphological point of view.

Trichorhina Budde-Lund, 1908 Trichorhina argentina Vandel, 1963

Trichorhina argentina VANDEL, 1963:73 , fig. 6; ARAUJO & BUCKUP, 1996a:800, figs 1-15, 41; LEISTIKOW & WÄGELE, 1999:28; SCHMALFUSS, 2003:275; LOPES et al., 2005:101, table 1; SOUZA et al., 2011:241; CAMPOS-FILHO et al., 2014:405; ZIMMERMANN et al., 2015b:3, table 1.

Material examined. BRAZIL, Santa Catarina: 3♂, ♀, Rancho Queimado, Bauer Hotel , 27°40’57”S, 49°02’41”W, 25.VI.2012, P. B. Araujo & B. L. Zimmermann col., impacted area, in woods (UFRGS 5571) .

Previous Brazilian records. Santa Catarina: JoaÇaba and Sombrio ( ARAUJO & BUCKUP, 1996a). Rio Grande do Sul: CaÇapava do Sul, CamaquÃ, Camobi (UFSM), Eldorado do Sul and Rio Grande (E. E. Taim) ( ARAUJO & BUCKUP, 1996a); RincÃo dos Kroeff and Barra do Ouro ( LOPES et al., 2005); Porto Alegre ( ZIMMERMANN et al., 2015b).

Distribution. This species is recorded from southern Brazil (states of Santa Catarina and Rio Grande do Sul) and eastern Argentina.

Figures

Figs 51-59. Amazoniscus schmidti Campos-Filho, Montesanto & Taiti sp. nov., ♂ holotype: 51, adult specimen, lateral view; 52, dorsal scale-seta; cephalon: 53, dorsal view; 54, caudal view; 55, cephalon and pereonites 1 and 2, frontal view; 56, pleonites 4 and 5, telson and uropods, dorsal view; 57, pleonites 4 and 5, and uropods, ventral view; 58 antennula; 59, antenna.

Figs 60-65. Amazoniscus schmidti Campos-Filho, Montesanto & Taiti sp. nov., ♀ paratype: 60, left mandible; 61, right mandible; 62, maxillula; 63, maxilla; 64, maxilliped; 65, uropod.

Figs 66-73. Amazoniscus schmidti Campos-Filho, Montesanto & Taiti sp. nov., ♂ holotype: 66, pereopod 1; 67 pereopod 7; 68, genital papilla; 69, pleopod 1; 70, pleopod 2; 71, pleopod 3 exopod; 72, pleopod 4 exopod; 73, pleopod 5 exopod.