A new species of Temnocephala Blanchard (Platyhelminthes, Temnocephalida) ectosymbiont on creeping water bugs, Cryphocricos granulosus De Carlo (Hemiptera, Naucoridae) from southern Brazil 1 José F. R. Amato 2; Samantha A. Seixas 2 & Suzana B. Amato 2 1 Contribution number 519 of the Departamento de Zoologia, Universidade Federal do Rio Grande do Sul. 2 Departamento de Zoologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul. Caixa Postal 15014, 91501-970 Porto Alegre, Rio Grande do Sul, Brasil. E-mail: [email protected]; [email protected]; [email protected] ABSTRACT. Temnocephala minutocirrus sp. nov.., an ectosymbiont on Cryphocricos granulosus De Carlo, 1967, is de- scribed from the State of Rio Grande do Sul, southern Brazil. One hundred and nine naucorids were examined, of which 36 (33%) were positive for this species of Temnocephala Blanchard, 1849. In one sample of 94 creeping water bugs, 49 (52%) were 4th instar nymphs, 6% of which were infested; 45 (48%) were adults, either brac- hypterous (40 with 18 males and 22 females) or macropterous (5 with 1 male and 4 females), 67% of which were infested (29% males and 38% females). Temnocephalan eggs were found both ventrally and dorsally: fixed on coxae, trochanters, and along the sternum between fore middle, and hind pairs of legs; basal of the abdominal area; and on the scutellum, clavus, and hemelytra. Juvenile and adult temnocephalans were always devoid of body pigmentation, and were found living on the ventral body surface, preferably over the sternum, between the middle and hind pairs of legs. The most distinctive features of this new species are: 1) unusually short cirrus, slightly curved, with introvert corresponding to 37% of its total length; 2) dorsolateral ‘excretory’ syncytial epidermal plates, elliptic, with excretory pore relatively equatorial, closer to inner limit of each plate; 3) two pairs of large disc gland cells (paranephrocytes?) located centrally, just ahead of testes; 4) testes relatively large, but unequal in size, anterior pair smaller, always in the same zone, those of the same side, partially superposed; and (5) vagina with weak muscular wall and without muscular sphincters. KEY WORDS. Ectocommensals; Neotropical Region; Rio Grande do Sul; South America; taxonomy. RESUMO. Nova espécie de Temnocephala Blanchard (Platyhelminthes, Temnocephalida) ectosimbionte sobre naucorídeos, Cryphocricos granulosus De Carlo (Hemiptera, Naucoridae) da Região Sul do Brasil. Temnocephala minutocirrus sp. nov.., ectosimbionte sobre Cryphocricos granulosus De Carlo, 1967, é descrita para o Estado do Rio Grande do Sul. Cento e nove naucorídeos foram examinados, dos quais 36 (33%) estavam positivos para esta espécie do gênero Temnocephala Blanchard, 1849. Em uma amostra de 94 hemípteros, 49 (52%) eram ninfas de 4º instar, das quais, 6% estavam infestadas; 45 (48%) eram adultos, braquípteros 40 (18 machos e 22 fêmeas) ou macrópteros 5 (1 macho e 4 fêmeas), 67% dos quais estavam infestados (29% machos e 38% fêmeas), para esta espécie de temnocefalídeo. Ovos dos temnocefalídeos estavam fixados na face ventral do hemíptero, sobre as coxas, trocânteres e esterno, entre o primeiro, segundo e terceiro pares de pernas e na face dorsal, sobre o escutelo, clavo e hemiélitros. Temnocefalídeos juvenis e adultos sempre se apresentaram sem pigmentação corpo- ral. Os caracteres mais distintivos da nova espécie são: 1) cirro muito curto, levemente curvo, com o ‘introvert’ correspondendo a 37% do comprimento total; 2) placas dorsolaterais, sinciciais ‘excretoras’ elípticas, com poro excretor equatorial, próximo do limite interno da placa; 3) dois pares de ‘grandes glândulas do disco’ (paranefrócitos?) centrais, imediatamente à frente dos testículos; 4) testículos relativamente grandes, mas desi- guais em tamanho, par anterior menor, sempre na mesma zona, aqueles do mesmo lado, parcialmente sobrepos- tos; e 5) vagina com parede muscular fracamente desenvolvida e sem esfíncteres musculares. PALAVRAS-CHAVE. América do Sul; ectocomensais; Região Neotropical; Rio Grande do Sul; taxonomia. Temnocephalans identified as Temnocephala lanei Pereira authors found these temnocephalans on several species of & Cuocolo, 1941, were collected for the first time on creeping Limnocoris Stål, 1860 (Naucoridae Leach, 1815) and on a species water bugs and water scorpions by VIANNA & DE MELO (2002). The of Ranatra Fabricius, 1790 (Nepidae Latreille, 1802) collected from Revista Brasileira de Zoologia 24 (4): 1043–1051, dezembro 2007 1044 J. F. R. Amato et al. streams of Serra do Cipó, Municipality of Santana do Riacho scope with Nomarski's differential interference contrast (DIC) (19º15’S, 043º32’W), and Retiro das Pedras (20º04’S, 044º00’W), prisms, and/or a Jeol (JSM-5800) SEM. Drawings were made Municipality of Brumadinho, State of Minas Gerais, Brazil. with a drawing tube on a Nikon E-200 microscope. Measure- Temnocephala lanei was originally described as an ments are in micrometers (µm) unless otherwise indicated; ectosymbiont of an undetermined species of Trichodactylus ranges are followed by the arithmetic mean, the number of Latreille, 1828 found at Fazenda Poço Grande, Municipality of specimens measured for a given character (when different than Juquiá, State of São Paulo (PEREIRA & CUOCOLO 1941). DAMBORENEA 12), and the standard deviation values (between parentheses). & CANNON (2001) while reviewing the Neotropical species of The holotype and some paratypes fixed in AFA, HF, and Temnocephala Blanchard, 1849, listed T. lanei, but did not col- SN, as well as slides containing individual cirri in deF and un- lect specimens nor present drawings of the cirrus and the dor- hatched eggs, were deposited in the Coleção Helmintológica do solateral, epidermal ‘excretory’ syncytial plates (DLSPs). Instituto Oswaldo Cruz (CHIOC), Rio de Janeiro, RJ, Brazil. Some The only complete study (description and illustrations) naucorid hosts were deposited in the Colorado Entomological of a species of Temnocephala from aquatic Heteroptera known Institute, Engelwood, Colorado, USA, while others were depos- to date is that of Temnocephala curvicirri Amato & Amato, 2005, ited in the Coleção do Departamento de Zoologia, Laboratório ectosymbiont on belostomatids in the State of Rio Grande do de Entomologia Sistemática, UFRGS (DZRS/UFRGS). The remain- Sul, southern Brazil (AMATO & AMATO 2005). The present paper ing host specimens and temnocephalans are in the host and adds a complete study on the second species of Temnocephala helminth collection of the Laboratório de Helmintologia (SBA), ectosymbiont on aquatic heteropterans. UFRGS, Porto Alegre, Rio Grande do Sul, Brazil. MATERIAL AND METHODS RESULTS Temnocephala minutocirrus sp. nov. One hundred and nine creeping water bugs were collected from 2002 to 2006, using dip nets, large sand sieves and/or a Figs 5-21 Surber sampler, and transported live to the Laboratório de Description. Based on 102 specimens collected; 36 adults, Helmintologia, Universidade Federal do Rio Grande do Sul whole-mounted; 19 juveniles; 2 specimens mounted on stubs (UFRGS). Live temnocephalans were obtained from hosts col- for SEM; 5 dissected cirri, mounted in deF; 6 mounted speci- lected from Arroio Forqueta (29º32’19”S, 050º14’47”W), Arroio mens, fixed in SN; 12 specimens measured, fixed in AFA under Garapiá (29º30’23”S, 050º14’38”W), both belonging to the Rio slight cover slip pressure. Maquiné Basin, District of Barra do Ouro, Municipality of External characteristics. Body (without tentacles) 530- Maquiné; and Rio da Divisa (28º38’17”S, 049º57’46”W), Mu- 1461 (250, 249) long; 480-970 (723, 150) wide (Fig. 6); adhe- nicipality of São José dos Ausentes, Rio Pelotas Basin; all in the sive disk ventral, subterminal, pedunculate, 170-370 (293, 61) State of Rio Grande do Sul, Brazil. Both areas are included in in diameter; live body pigmentation absent in juvenile and adult the Atlantic Rain Forest (Brazilian Atlantic Forest Biome). specimens (Fig. 8). Eyespots round, with red pigment in live Some helminths taken from live hosts were fixed and specimens; pigment dissolving in specimens fixed in ethanol, prepared for internal morphometry according to AMATO et al. but not in formalin. Epidermal mosaic with two dorsolateral, (2005). To preserve eyespot pigmentation, body shape, and for elliptical DLSPs (Figs 10 and 16-17), extending from basis of scanning electron microscope (SEM) studies, some specimens first and fifth tentacles, respectively; left plate 123-160 (140, were flooded with hot formalin (HF) (AMATO et al. 2006). Mor- n = 3, 19) long, 48-93 (68, n = 3, 23) wide; right plate 108-230 phology of dorsolateral ‘excretory’ syncytial epidermal plates (158, n = 5, 48) long, 58-155 (85, n = 5, 41) wide; relationship (DLSPs) was studied in specimens fixed with silver nitrate (SN) between length of DLSPs/total body length, without tentacles, (ROMEIS 1968, JOFFE et al. 1995) or observed with SEM (AMATO et 3.5: 1. Excretory pore (nephridiopore) near or a little below al. 2005). Cirrus morphology was studied after microdissection the equatorial line of the DLSPs and closer to the inner margin and mounting in de Faure’s (deF) medium (CANNON & SEWELL of each syncytial plate (Figs 10 and 16-17). 1995); cirrus measurements follow AMATO et al. (2005). Distri- Alimentary system. Mouth surrounded by a small mus- bution of rhabditogenic and disc glands was studied by clear- cular sphincter, between first and second thirds of body; phar- ing small juvenile specimens in lactophenol