Notes on the holotype of Anopheles marajoara Galvão & Damasceno (Diptera, Culicidae)

Sobre o holótipo de Anopheles marajoara Galvão & Damasceno, 1942 (Diptera, Culicidae)

SYSTEMATICS, MORPHOLOGY AND BIOGEOGRAPHY

Notes on the holotype of Anopheles marajoara Galvão & Damasceno (Diptera, Culicidae)

Sobre o holótipo de Anopheles marajoara Galvão & Damasceno, 1942 (Diptera, Culicidae)

Luana Senise; Maysa Tiemi Motoki; Maria Anice Mureb Sallum

Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, Avenida Dr. Arnaldo 715, 01246-904 São Paulo-SP, Brazil. [e-mail]; [e-mail]; [e-mail]

^{Corresponding author}

ABSTRACT

During studies on the dynamics of malaria transmission in Marajó Island, State of Pará, Brazil, Galvão & Damasceno (1942) collected a single specimen of a new species that they named Anopheles (Nyssorhynchus) marajoara Galvão & Damasceno, 1942. Now, examining genitalia slide associated to the holotype, we observed that the ventral claspette of the male genitalia is distinct from those of all other species of the Argyritarsis Section and consequently from members of the complex Anopheles albitarsis Lynch Arribalzaga, 1878. The male genitalia of the slide belong to a specimen of Anopheles aquasalis Curry, 1932, nevertheless, it was originally labeled as Anopheles marajoara. To solve this problem, we are setting aside the male genitalia slide associated with the holotype of Anopheles marajoara and excluding it from the type material. Illustrations of the male genitalia and adult male are included.

Keywords:Anopheles albitarsis Complex; Culicidae; holotype; Nyssorhynchus.

RESUMO

Durante estudos sobre a dinâmica de transmissão da malária na Ilha de Marajó, Estado do Pará, Brasil, Galvão & Damasceno (1942) coletaram um espécime de nova espécie de anofelíneo, que foi denominada Anopheles (Nyssorhynchus) marajoara Galvão & Damasceno, 1942. Ao examinarmos a lâmina com a genitália, que acompanha o holótipo, observamos que o claspete ventral da genitália masculina difere daqueles apresentados pelas espécies da Seção Argyritarsis e, conseqüentemente, de membros do Complexo Anopheles abitarsis Lynch Arribalzaga, 1878. Consideramos que a genitália masculina que foi montada na lâmina associada ao holótipo pertence a um espécime de Anopheles aquasalis Curry, 1932, embora o adulto e as exúvias de larva e da pupa sejam de Anopheles marajoara. Com o intuito de resolver este problema , nós excluímos a lâmina com a genitália de macho do material tipo de Anopheles marajoara. A título de elucidação, foram feitas ilustrações da genitália masculina em questão, bem como do adulto de An. marajoara.

Palavras-chave: Complexo Anopheles albitarsis; Culicidae, holótipo; Nyssorhynchus.

Anopheles subgenus Nyssorhynchus is a monophyletic Neotropical group (Sallum et al. 2000, 2002) that currently contains 32 named species (Harbach 2004). The most important vectors of human malaria parasites in Central and South America are members of the subgenus and include An. darlingi Root, 1926, An. albimanus Wiedemann, 1820 and An. marajoara Galvão & Damasceno, 1942 (Conn et al. 2002). Anopheles marajoara belongs to a group of morphologically similar species, the Albitarsis Complex, which also contains An. albitarsis Lynch-Arribálzaga, 1878, An. deaneorum Rosa-Freitas, 1989 and An. albitarsis "B" of Wilkerson et al. (1995). The An. albitarsis Complex species are largely indistinguishable morphologically with nearly all characters in all stages either identical or overlapping. Anopheles albitarsis s. l. was suspected to contain more than one species by various authors based on epidemiological, behavioral, morphological, cytological, and biochemical evidences (Galvão and Damasceno 1944; Kreutzer et al. 1976; Linthicum 1988; Rosa-Freitas and Deane 1989; Rosa-Freitas et al. 1990; Narang et al. 1993). Wilkerson et al. (1995) using random amplified polymorphic DNA (RAPD-PCR) demonstrated the existence of the above four species. Recently, Lehr et al. (2005) hypothesized a fifth species (An. albitarsis E) in northern Brazil and Venezuela related to An. marajoara based on complete sequence of the cytochrome c oxidase I gene (COI).

Anopheles marajoara was demonstrated to be involved in the dynamics of the transmission of human malaria in the Amazon Region. Population studies using molecular markers for species identification showed a significant increase in infected adults female of An. marajoara by Plasmodium Marchiafava & Celli, 1885, in Macapá, State of Amapá, Brazil. Consequently, the importance of An. marajoara in the dynamics of the malaria transmission in Macapá is currently higher than that of An. darlingi. More important, the change in the forest environment caused by a continuous, unplanned urbanization and human migration are creating ecological conditions that are adequate for survivorship and dispersion of An. marajoara (Conn et al 2002). Also, An. deaneorum was infected by P. falciparum and P. vivax (Klein et al. 1991) in the laboratory.

During studies on the dynamics of malaria transmission in Cachoeira do Arari (01º00'36''S 48º57'36''W), Marajó Island, State of Pará, Brazil, Galvão and Damasceno (1942) collected immatures of An. albitarsis, An. aquasalis Curry, 1932 (identified as Anopheles tarsimaculatus var. aquasalis Curry, 1932) and a single larva of a new species named An. (Nyssorhynchus) marajoara. The collection site was situated in Santa Maria Farm, 400 meters distant from Camará River that is the natural limit between Cachoeira do Arari and Salvaterra municipalities and runs into the Marajó Basin. In the breeding habitat, the water was turbid, polluted, standing, with fishes and immatures of several insect species.

Galvão & Damasceno (1942) named and defined Anopheles marajoara based on morphological characters of the fourth-instar larva, pupa and adult male, including those of the male genitalia, and designated the holotype, which was deposited in the Entomological Collection of the Parasitology Department of Faculdade de Medicina, Universidade de São Paulo (FMUSP). The accession number in the collection was FMUSP 619. The FMUSP Entomological Collection was transferred to Faculdade de Saúde Pública, Universidade de São Paulo (FSP-USP), in the early 1970s. Consequently, the holotype of An. marajoara was deposited in the FSP-USP where it has the accession number E-2120.

Galvão & Damasceno (1944) compared specimens of An. albitarsis collected in the Marajó Island with samples from the State of São Paulo, Brazil, and from Tucuman, north Argentina, thus found morphological and ethological differences between the south and north populations. Although the egg of the specimens of the Marajó Island population was morphologically similar to that of São Paulo population, they differed in the exocorion that in the former population was somewhat a mosaic. Also, the adults of the Marajó Island were smaller when compared to samples from São Paulo. Anopheles albitarsis samples collected in Tucuman were morphologically more similar to those of São Paulo than to those of Marajó Island. Additionally, Tucuman samples were exophilic and exophagic, whereas those from Marajó Island were collected in the intradomiciliary environment. Because of those differences, the Marajó Island population was considered to be a subspecies named Anopheles albitarsis domesticus Galvão & Damasceno, 1944. Galvão & Lane (1937) described Anopheles albitarsis limai Galvão & Lane, 1937 using samples obtained in Pinheiros and Butantan Districts in São Paulo municipality, and Corrêa & Ramos (1943) named Anopheles albitarsis imperfectus Corrêa & Ramos, 1943 based on specimens from Vera Cruz, both municipalities of State of São Paulo, Brazil. Lane (1953) considered An. albitarsis limai, An. albitarsis imperfectus and An. marajoara to be morphological variants of An. albitarsis, which were transferred to the synonymy of An. albitarsis albitarsis.

Belkin et al. (1971) restricted the type locality of An. marajoara to the limits of Cachoeira do Arari, and accepted the synonymy of this species with An. albitarsis. Additionally, they considered that there was a type-series "Type: males, females, larvae" (page 4) for An. marajoara. However, in the present study, we are considering the type series as an invalid designation for the following fact. Galvão & Damasceno (1942) declared that the holotype of An. marajoara was an adult male, which was deposited in FMUSP. The adult male is associated with the fourth-instar larval and pupal exuviae and male genitalia.

Linthicum (1988) studied the species of the Argyritarsis Section and resurrected An. marajoara from the synonymy of An. albitarsis. Additionally, Linthicum transferred An. albitarsis domesticus to the synonymy of An. marajoara. Interestingly, in his revision, Linthicum illustrated the male genitalia of a specimen of An. marajoara collected in the Canal Zone, Panama. However, we observed that in the illustration (Figure 14, page 266), both the ventral claspette and the apex of the aedeagus differ from those of An. albitarsis (Figure 12, page 264) and Anopheles deaneorum Rosa-Freitas, 1989. Both species, An. albitarsis and An. deaneorum show nearly identical ventral claspette and aedeagus. Consequently, we are considering that the morphological characters described for An. marajoara by Linthicum (1988), specially those in Figure 14 should be analyzed carefully because it is possible that they are of an undescribed species of the An. albitarsis Complex.

Guimarães (1997) considered "Cachoeira do Colombia" (page 26) to be the type locality of An. marajoara. We believe that this information in incorrect because there is none locality named Cachoeira do Colombia in Marajó Island. It is possible that Guimarães was mentioning Cachoeira municipality. Cachoeira do Arari was previously designated as both Cachoeira and Arari (Governo do Pará, 2005). Colombia is the country where An. marajoara was also reported in addition to Guyana, French Guyana, Bolivia and Brazil.

While examining the male genitalia slide associated with the holotype of An. marajoara, we observed that the ventral claspette is distinct from those of all other species of the Argyritarsis Section and consequently from members of the An. albitarsis Complex. The adult male holotype of An. marajoara is in good condition (Figs. 1-7), as well as the associated larval and pupal exuviae, which are both mounted on a microscope slide that has two labels with inscription "nº 619, nota 812-1, D.H. 384, Marajó, Pará, Alfaia col. 1941" and " Anopheles (N.) marajoara n. sp. Galvão et Damasceno det. 1941". The male genitalia (Figs. 4-7) was dissected and mounted on a microscope slide separate from the immatures and brings two labels with inscription " no 819, nota 821-1, D. H. 383, Marajó, Pará, Alfaia col. 1941" and "Anopheles (N.) marajoara n. sp. Galvão et Damasceno det. 1941". The adult male is mounted on the apex of a little white triangle on an entomological pin, and brings two labels with inscription "Anopheles (N.) marajoara n. sp. Galvão & Damasceno 1942" and "435-12". Additionally, two labels were added when the holotype was transferred from FMUSP to FSP-USP collection, one label with the accession number E-2120 and the other is a red holotype label.

By examining the adult holotype (Figs. 1-7), we observed that it can be easily recognized as a species of the An. albitarsis Complex of the Argyritarsis Section by having the sternum I with a submedial stripe of white scales (Fig. 2); the hindtarsomere V entirely covered with white scales (Fig. 3); and caudolateral scale tufts absent on abdominal segment II. Regarding to the fouth-instar larval and pupal exuviae associated with the adult male, we can also recognize both as members of the An. albitarsis Complex. The pupa by having seta 9-V short, less than or equal to 3.0 length of 9-IV; seta 3-C triple; and pinna of trumpet moderately long. The fourth-instar larva shares the following characters with other members of the An. albitarsis Complex: seta 1-P always palmate with lanceolate branches; 1,2-P inserted on a common sclerotized tubercle; setae 3-T and 1-I palmate, with well-developed lanceolate branches; seta 2-C widely spaced; and pecten with median teeth mostly subequal. In contrast, the male genitalia associated with the holotype of An. marajoara can be recognized as of a specimen of the Albimanus Section. Obviously, it is the same individual described and illustrated by Galvão & Damasceno (1942). Arguing in favor of our hypothesis there are the following facts: according to Linthicum (1988) members of the Argyritarsis Section can be distinguished from those of the Albimanus Section, except Anopheles albimanus, by the lack of spicules on the ventral claspette and the preapical plate and the refringent structure are at most weakly developed and are often absent. Additionally, members of the Albitarsis Subgroup are distinct from those of the Albimanus Section by possessing the aedeagus without subapical leaflets, apex of ventral claspette somewhat rounded, with a moderately shallow median sulcus, dorsal claspette narrow, apical setae without a well-developed basomesal projection, and preapical plate absent. The male genitalia associated with the holotype of An. marajoara (Figs. 4-7) can be easily identified as An. aquasalis by having the following characters, listed in Faran (1980): ventral claspette spiculate (Figs. 5, 6); setae along basal margin of basal lobule of ventral claspette moderately short, about equal to or slightly longer than width of aedeagus, setae usually not reflexed; and preapical plate moderately small, circular to oval and weakly sclerotized (Figs. 5, 6). In agreement with our hypothesis that the male genitalia is not derived from the adult male designated as holotype, it is important to say that Galvão & Damasceno (1942) collected specimens of An. aquasalis (as An. tarsimaculatus) and An. albitarsis in association with An. marajoara. It is possible that either during the preparation process or by labeling mistake, the male genitalia of an An. aquasalis specimen had been labeled as the male genitalia of the holotype of An. marajoara. Unfortunately, except for the holotype of An. marajoara there is no other specimen either of An. aquasalis or An. albitarsis collected in Ilha do Marajó by Galvão & Damasceno (1942) that has been deposited in the FSP-USP collection. Also, in favor of our hypothesis, new recent collections carried out in the type locality in Marajó Island allowed us to examine adults male and female associated with immature stages and male genitalia. All male genitalia which we have examined are distinct from that associated with the holotype of An. marajoara, but similar to those of members of the An. albitarsis Complex. The International Code of Zoological Nomenclature (1999), article 73.1.5 says "if a subsequent author finds that a holotype which consists of a set of components (e.g. disarticulated body parts) is not derived from an individual animal, the extraneous components may, by appropriate citation, be excluded from the holotype." Consequently, with the International Code of Zoological Nomenclature endorsement and considering the epidemiological importance of An. marajoara, the slide with male genitalia associated with the holotype of An. marajoara was set aside and excluded from the type material, because it belongs actually to another species as evidences pointed out.

Acknowledgments. We are thanks to FAPESP grant number 05/53973-0. Professor Albino Sakakibara is acknowledged for providing critical comments. W. Senise and D. Alonso helped in elaborating the illustrations.

Received 25/01/2006; accepted 23/10/2006

• Belkin, J. N.; R. X. Schick & S. J. Heinemann. 1971. Mosquito Studies (Diptera, Culicidae). XXV. Mosquitos originally described from Brazil. Contribution of American Entomological Institute (Ann Arbor) 7: 164.
• Conn, J. E.; R. C. Wilkerson; M. N. Segura; R. T. de Souza; C. D. Schlichting; R. A. Wirtz & M. M. Povoa. 2002. Emergence of a new Neotropical malaria vector facilitated by human migration and changes in land use. American Journal of Tropical Medicine and Hygiene 66: 1822.
• Corrêa, R. R. & A. S. Ramos. 1943. Descrição de uma nova subespécie de anofelino do subgênero Nyssorhynchus Blanchard 1902 (Diptera, Culicidae). Revista Paulista Medica 22: 246248.
• Faran, M. E. 1980. Mosquito Studies (Diptera, Culicidae). XXXIV. A revision of the Albimanus Section of the subgenus Nyssorhynchus of Anopheles Contribution of American Entomological Institute (Ann Arbor) 15: 7588.
• Galvão, A. L. A. & R. G. Damasceno. 1942. Sobre um novo anofelino da Ilha de Marajó, Anopheles (Nys.) marajoara n. sp. Folia Clinica Biologica 14: 6066.
• Galvão, A. L. A. & R. G. Damasceno. 1944. Observações sobre os anofelinos do complexo Albitarsis (Diptera, Culicidae). Annais da Faculdade de Medicina 20: 7387.
• Galvão, A. L. A. & J. Lane. 1937. Nota sobre os Nyssorhynchus de São Paulo. VII. Estudo sobre as variedades deste grupo com a descrição de Anopheles (Nyssorhynchus) albitarsis Arrib. 1878 var. limai n. var. Annais da Faculdade de Medicina de São Paulo 13: 227.
• Governo do Pará. 2005. http://pa.gov.br/conhecaopara/cachoeiradoarari.asp (accessed in 15th August 2005).
• Guimarães, J. H. 1997. Systematic Database of Diptera of the Americas South of the United States (Family Culicidae) . São Paulo, Brasil, Plêiade/ Fapesp, 286 p.
• Harbach, R. E. 2004. The classification of genus Anopheles (Diptera: Culicidae): a working hypothesis of phylogenetic relationships. Bulletin of Entomological Research 94: 537553.
• ICZN. 1999. International Code of Zoological Nomenclature, 4th edn. The International Trust for Zoological Nomenclature, NHM, London, 306 p + xxix.
• Klein, T. A.; J. B. Lima; M. S. Tada & R. Mille. 1991. Comparative susceptibility of anopheline mosquitoes in Rondonia, Brazil to infection by Plasmodium vivax American Journal of Tropical Medicine and Hygiene 45: 463470.
• Kreutzer, R. D.; J. B. Kitzmiller & M. G. Rabbani. 1976. Cytogenetically distinguishable sympatric and allopatric populations of the mosquito Anopheles albitarsis Acta Amazonica 6: 473481.
• Lane, J. 1953. Neotropical Culicidae São Paulo, Brasil, Universidade de São Paulo, 548 p.
• Lehr, M. A.; C. W. Kilpatrick; R. C. Wilkerson & J. E. Conn. 2005. Cryptic species in the Anopheles (Nyssorhynchus) albitarsis (Diptera: Culicidae) Complex: Incongruence between random amplified polymorphic DNA-polymerase chain reaction identification and analysis of mitochondrial DNA COI gene sequences. Annals of the Entomological Society of America 98: 908917.
• Linthicum, K. J. 1988. A revision of the Argyritarsis Section of the subgenus Nyssorhynchus of Anopheles (Diptera: Culicidae). Mosquito Systematic 20: 98271.
• Narang, S. K.; T. A. Klein; O. P. Perera & A. T. Tang. 1993. Genetic evidence for the existence of cryptic species in the Anopheles albitarsis complex in Brazil: allozymes and mitochondrial DNA restriction fragment length polymorphisms. Biochemical Genetics 31: 97112.
• Rosa-Freitas, M. G. 1989. Anopheles (Nyssorhynchus) deaneorum: a new species in the Albitarsis Complex (Diptera: Culicidae). Memórias do Instituto Oswaldo Cruz 84: 535543.
• Rosa-Freitas, M. G.; L. M. Deane & H. Momen. 1990. A morphological isoenzymatic and behavioral study of ten populations of Anopheles albitarsis Lynch-Arribalzaga 1878 (Diptera: Culicidae) including from the type locality, Baradero, Argentina. Memórias do Instituto Oswaldo Cruz 85: 275290.
• Sallum, M. A. M; T. R. Schultz & R. C. Wilkerson. 2000. Phylogeny of Anophelinae (Diptera, Culicidae) based on morphological characters. Annals of the Entomological Society of America 93: 747775.
• Sallum, M. A. M.; T. R. Schultz; P. G. Foster; K. Aronstein; R. A. Wirtz & R. C. Wilkerson. 2002. Phylogeny of Anophelinae (Diptera: Culicidae) based on mitochondrial and nuclear ribosomal DNA sequences. Systematic Entomology 27: 361382.
• Wilkerson, R. C.; T. J. Parsons; T. A. Klein; T. V. Gaffigan; E. Bergo & J. Consolim. 1995. Diagnosis by random amplified polymorphic DNA polymerase chain reaction of four cryptic species related to Anopheles (Nyssorhynchus) albitarsis (Diptera: Culicidae) from Paraguay, Argentina, and Brazil. Journal of Medical Entomology 32: 697704.

Publication Dates

• Publication in this collection
  30 Jan 2007
• Date of issue
  Dec 2006

History

• Accepted
  23 Oct 2006
• Received
  25 Jan 2006