New species and a new record of Isotomidae (Collembola) from the coast of Brazil Author Abrantes, Eduardo Assis Author Mendonça, Maria Cleide De text Zootaxa 2007 2007-06-07 1500 1 55 60 journal article 10.11646/zootaxa.1500.1.2 1175­5334 5088000 8ED9B600-B548-4192-8B65-A44F3DAE5DB2 Isotomodes fernandesae sp. nov. Figs 11–17 Description. Habitus typical of the genus. Body length 0,59 mm – 0,98 mm . Without pigment. Integument minutely granulated. Dorsal chaetotaxy of the head and the body as in Figs 11 and 12 . Postantennal organ oval, with 8–9 setae along posterior margin ( 18 µm ) shorter than the first antennal segment diameter ( Fig. 11 ). Antennae slightly longer than head; ratio antenna: head = 1: 1,4. Antennal segment IV with about 20 dorsal sensilla; one apical microsensillum and one small organ in a shallow depression ( Fig. 13 ). Antennal segment III with about 21 setae, sensory organ of antennal segment III oval, covered by an integumentary fold and protected by two guard sensilla; one short ventro-external sensillum. Antennal segment II with about 19 small acuminate setae; two basal microsetae, one dorsal and one ventral. Antennal segment I with about 11 setae; three basal microsetae, two dorsal and one ventral. Antennal segments ratio I: II: III: IV = 1: 1,32: 1,5: 2,14. Axial dorsal chaetotaxy from thorax II to abdominal III as 8,6/4,4,5. Macrochaetotaxy: 1,1/1,1,1,1. Sensillar formula from thorax II to abdominal III (s + ms): 4,3/2,2,2. Abdominal segment IV with 1+1 dorsal lateral sensillum ( 14 µm ) and 4 m-setae presents. Abdominal segment V with 4+4 dorsal microsetae and 1+1 dorsal lateral sensillum. Abdominal segment IV with p 1 and p 3 spiniform, short and denticulated ( 25–30 µm ), p 2 and p 5 long and barbulated ( 55 µm ), p 0 and p 4 smooth, 1+1 ventral sensillum ( Figs 14–15 ). Tibiotarsi I, II and III with 23, 23, 25 setae respectively. Unguis unthoothed with strong lateral spine, unguiculus whit half size of unguis ( Fig. 16 ). Ventral tube ( 40 µm ) with 4+4 distal and 2+2 posterior setae. Tenaculum with 4+4 teeth and one seta on corpus. Subcoxa furcalis anterior with four setae, posterior with three seta. Manubrium with 13 pairs of setae on posterior surface. Dens with two internal hooks, 2 long posterior setae, 6 short anterior setae. Mucro bidentate. Ratio manubrium: dens: mucro = 10,8: 4,1: 1 ( Fig. 17 ). Male genital opening with 3+3 lateral setae and one pair of anterior setae. Type locality : Restinga de Maricá , Maricá city, Rio de Janeiro State , Brazil . Found in sand beach . Type material : Brazil : Rio de Janeiro State : Maricá city, Restinga de Maricá , female holotype on slide Nº 1339 CM / MNRJ , 31.vii.2003 , L.H. Fernandes & E.A. Abrantes. coll.; two paratypes on slide N° 1259 CM / MNRJ , 28.i.2003 ; one paratype on slide N° 1279 CM / MNRJ , 28.i.2003 ; one paratype on slide N° 1280 CM / MNRJ , 28.i.2003 ; one paratype on slide N° 1282 CM / MNRJ , 28.i.2003 ; one paratype on slide N° 1283 CM / MNRJ , 28.i.2003 ; one paratype on slide N° 1365 CM / MNRJ , 31.vii.2003 ; one paratype on slide N° 1366 CM / MNRJ , 31.vii.2003 ; Brazil : Rio de Janeiro State , Rio de Janeiro city, Restinga da Marambaia , one paratype on slide Nº 1639 CM / MNRJ , 16.xii.2006 ; one paratype on slide Nº 1639 CM / MNRJ , 16.xii.2006 . Discussion : The genus Isotomodes Linnaniemi, 1907 , world wide distributed, has 13 species known from the Neotropical Zone, but only two from Brazil : I. trisetosus Denis, 1923 (Amazon Rain Forest) and I. carioca Thibaud & Palacios-Vargas, 1999 (Maricá sand beach). The new species is clearly separated from those two by a series of characters. Isotomodes fernandesae sp.nov. is closest to the species I. bahiensis Rapoport, 1962 from Bahia Blanca, Argentina . Although the lack of information concerning the taxonomical characters of I. bahiensis species, such as dorsal chaetotaxy, its possible to separate both species by the number of microseta m on abdominal IV, 6 on I. bahiensis and 4 on Isotomodes fernandesae sp.nov. and the setae p 1 , p 2 , p 3 , p 5 are barbulate in the new species, different from the smooth seta in I. bahiensis . Derivatio nominis . This species is dedicated to Dr. Liliane Henriques Fernandes for their unconditional friendship and technical support.