Morphological regional differences of epithelial cells along the midgut in Diatraea saccharalis Fabricius (Lepidoptera : Crambidae) larvae

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cytodifferentiation during the spermatogenesis of the hermaphrodite caridea Exhippolysmata oplophoroides

Among the decapods, the caridean Exhippolysmata oplophoroides has been described as a simultaneous protandric hermaphrodite, seeing that it presents a male initial stage followed by a hermaphrodite one in which it can function as male and as female. This work had the aims of characterizing the microscopical morphology of the male portion of the ovotestes gonads from E. oplophoroides, at the different development stages, identifying each cell from the germ lines during spermatogenesis, as well as describing the ultramorphology of spermatozoans in the terminal region of the vasa deferentia. Shrimps were collected in Ubatuba, north coast of São Paulo, and their male gonads and the ampoule were removed, fixed and processed according to histological routine and for scanning electron microscopy. The testicular portion is divided in lobes, inside which cells at the same stage of the spermatogenic cycle are observed, with prevalence of spermatogonia and spermatocytes at stages I, II and V of gonad development, whereas spermatids and spermatozoans are found at stages III and IV, respectively. Ultramorphology of the terminal portion of the vasa deferentia exhibits mature aflagellated spike-shaped spermatozoans, encased in secretion and between membrane foldings that will constitute the spermatophores. Despite presenting reproductive characteristics common to other decapods. E. oplophoroides shows spermatozoans as well as spermatophore with typical morphology, which is important for its identification and taxonomy. Further, this species showed polysaccharide secretions where the spermatozoa are immerse as far as the testicular portion, which could have a roe in their transport and nutrition as well as spermatophore constitution and/or fixation; differently, other caridean species begin spermatophore formation during the passage of the gametes through the vasa deferentia. (C) 2010 Elsevier Ltd. All rights reserved.

The influence of initial feeding on muscle development and growth in pacu Piaractus mesopotamicus larvae

The effects of different feeding schemes on pacu Piaractus mesopotamicus early development were evaluated with respect to growth, survival, muscle development, and differential gene expression of MyoD and myogenin. The pacu larvae (4 days post hatch-dph, 0.77 mg wet weight) were given six feeding treatments intentionally designed to cause variations in the larvae growth rate: (A) only artemia nauplii; (CD) only a commercial diet; (ED) only a semi-purified experimental diet; (ACD) and (AED) two treatments that involved weaning; and (S) starvation. Early weaning from artemia nauplii to the formulated diets (ACD and AED) affected growth and survival of the pacu larvae compared with the exclusive use of artemia (A). Starvation (S) and the commercial diet (CD) caused total mortality in pacu larvae at 18 dph. The experimental diet (ED) assured low fish survival and growth. The skeletal muscle morphology was not affected by the delay in somatic growth from early weaning onto the formulated diets. Three distinct muscle compartments were observed throughout the larval development in treatments A, ACD and AED: superficial, deep and intermediate, accompanied by muscle thickening. Severe undernourishment caused drastic differences in growth and in the morphology of the muscle fibers. Pacu larvae fed only formulated diets (CD and ED) showed muscle characteristics similar to the larvae in starvation (S) during the first 15 dph. At 27 and 35 dph, a slight increase in epaxial muscle mass was noted in larvae fed only the experimental diet (ED). At 35 dph, we observed a high frequency of fibers >= 40 mu m in the larvae that were weaned onto the formulated diets (ACD and AED), indicative of hypertrophy. In contrast, the larvae fed only artemia nauplii (A) displayed a larger number of fibers with diameters <= 20 mu m, which is indicative of hyperplasia. The expression of the MyoD and myogenin genes in pacu larvae at 35 dph was not affected by initial feeding (p>0.05). In conclusion, the formulated diets used impaired pacu larvae growth and survival; therefore, they were inadequate for pacu, at least at the times they were introduced. Artemia nauplii were the most adequate food source during first feeding of the pacu, and they produced bigger fish upon completion of the experiment. Moreover, the contribution of hyperplasia to the skeletal muscle growth appeared higher in fast- than in slow-growing pacu larvae. (C) 2011 Elsevier By. All rights reserved.

Ultramorphology of digestive tract of Anticarsia gemmatalis (Hubner, 1818) (Lepidoptera : Noctuidae) at final larval development

The digestive tract of insects is an important natural, physical, and chemical defense barrier against pathogen invasion. Certain. lepidopteran caterpillars are serious pests of agricultural crops and their biology has received much attention, but little is known about the larval noctuid gut. The morphological analysis of the digestive tract in Anticarsia gemmatalis under scanning electron microscopy (SEM) is a good model for studies about its defense mechanism. The material was fixed (2,5% glutaraldehyde solution; 0.1 M-phosphate buffer, pH 7.3), post-fixed (1% osmium tetroxide in the same buffer), dried at critical point, gold coated and analyzed in a SEM 515-Philips. A. gemmatalis digestive tract consists of a straight duct of varying length and diameter, subdivided in three main regions: the foregut formed by the oral cavity, pharynx, esophagus, and crop; the midgut that is the largest portion of the digestive tract without noticeable morphological differentiation along its length; and the hindgut that is morphologically differentiated in pylorus, ileum, colon, and rectum. Although the general morphology of the A. gemmatalis digestive tract is quite similar to the other Lepidoptera species, the anatomical array of the crop muscular layers is quite different comparing with the description for other larval insect.

Occurrence of Amphiorchis solus (Simha & Chattopadhyaya, 1970) (Digenea: Spirorchiidae) Infecting the Green Turtle Chelonia mydas Linnaeus, 1758 (Testudines: Cheloniidae) in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Reproductive cycle and recruitment period of Ocypode quadrata (Decapoda, Ocypodidae) at a sandy beach in southeastern Brazil

The reproductive cycle and recruitment period of a ghost crab population from Ubatuba, São Paulo, Brazil were investigated by means of examining the developmental stages of gonads of breeding crabs and the ingress of young recruits to the studied population. Monthly collections over a one-year period were carried out during nocturnal low-tide periods at Vermelha beach. The morphology of the abdomen and pleopods was used for sex determination. All captured crabs were measured for carapace width and dissected for the determination of the development stage of the gonads. A total of 582 specimens was captured: 271 males, 241 females, and 70 juveniles. Size ranged from 8.5 to 37.5 mm for males, from 9.5 to 39.2 mm for females, and from 5.8 to 12 mm for early juveniles. Median size of males and females did not differ statistically. The frequency of ovigerous females was markedly low. The onset of sexual maturity in females is achieved at around 23 mm of carapace width. Mature females with advanced gonad stages were not recorded from May to September. Recruitment of young was highest during summer, but the presence of early and late juvenile specimens throughout the year indicates that continuous recruitment is taking place in the studied population.

The dawn of animal skeletogenesis: Ultrastructural analysis of the Ediacaran metazoan Corumbella werneri

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Structural and cytochemical changes in the salivary glands of the Rhipicephalus (Boophilus) microplus (CANESTRINI, 1887) (Acari : Ixodidae) tick female during feeding

This study describes the morphology of salivary glands of Rhipicephalus (Boophilus) microplus female ticks at beginning of feeding (24-48 h of attachment) and semi-engorged (4-5 days of attachment) to verify the degenerative characteristics of these organs and the secretory phase in which the process begins. At the beginning of feeding, secretion granules had been observed only in the cytoplasm of cells b, c(1), c(2), c(4) (type II acinus) and d (type III acinus), as well as large nuclei with regular and preserved morphology. In the semi-engorged females the acini presented few normal cells, few partially preserved ones, and the remaining ones in several stages of degeneration, that is, with retraction and cytoplasmic vacuolization, and nuclei with chromatin in several stages of condensation, picnotic and/or in fragmentation. In type I acinus and in the excretory ducts of the studied glands, at both feeding stages, no degenerative characteristic was observed. In females of R. (B.) microplus, the salivary glands degenerate asynchronically and precociously when compared with those of others tick's species. (c) 2006 Elsevier B.V. All rights reserved.

Morphological, histological, and ultrastructural studies of the ovary of the cattle-tick Boophilus microplus (Canestrini, 1887) (Acari : Ixodidae)

This study presents the morphology of the ovary, as well as the dynamics of the vitellogenesis process in oocytes of the cattle-tick Boophilus microplus. The ovary of these individuals is of the panoistic type; therefore, it lacks nurse cells. This organ consists of a single tubular structure, continuous, and composed of a lumen delimitated by a wall of small epithelial cells with rounded nuclei. In this tick species, the oocytes were classified into six stages varying from I to VI and according to: cytoplasm appearance and presence of the germ vesicle, yolk granules, and chorion. Oocytes of various sizes and at different developmental stages remain attached to the ovary through a cellular pedicel until completing stage V. Afterwards, they are liberated into the lumen and from there to the exterior. Some oocytes (classified as type VI) showed an atypical appearance indicating that some of the cellular components would be undergoing a degenerative process and/or reabsorption. (c) 2004 Elsevier B.V. All rights reserved.

Morphological characterization of the ovary and vitellogenesis dynamics in the tick Amblyomma cajennense (Acari : Ixodidae)

In this work we describe the internal morphology of the female reproductive system of the cayenne tick Amblyomma cajennense. This system is represented by a panoistic ovary, which lacks nurse cells in the germarium. This ovary consists of a single tube, in which a large number of oocytes develop asynchronously, thus accompanying the processes of yolk deposition in the oocytes. The oocytes were classified into stages that varied from I to V, according to: cytoplasm appearance, presence of the germ vesicle, presence of yolk granules, and presence of chorion. The study of vitellogenesis dynamics suggest that the yolk elements are deposited in the oocyte following a preferencial sequence, in which the lipids are the first to appear, followed by proteins an finally by the carbohydrates. In this way the yolk of A. cajennense ticks have these three elements that may be free in the cytoplasm or chemically bounded forming glycoprotein or lipoprotein complexes. (C) 2004 Elsevier B.V. All rights reserved.

Secretory cycle of the Dufour's gland in workers of the bumble bee Bombus terrestris L-(Hymenoptera : Apidae, Bombini)

The Dufour's gland of Bombus terrestris workers, of different ages and with varying degrees of ovary development, was studied with the aim to verify its involvement in reproduction. Measurements of the diameter and the length of the gland were made using an ocular micrometer adapted to a microscope. Transmission electron microscopy was used to study the morphology of the secretory cells and to analyze the secretory cycle. The glandular cells were considered to be near type II cells of NOIROT and QUENNEDEY (1974), a type that has not been described before in Hymenopterans. The results show that there is a correlation between the degree of ovary development and Dufour's gland activity of workers. The diameter of the gland and the secretory cell activity increased with increasing oocyte size in the ovary. Regressive conditions of the gland were observed, which are probably related to increasing worker age. To elucidate the production and releasing process of the secretion and to establish its precise function, a comparative analysis of the secretion process of the Dufour's gland of queens and workers is needed.

Morphological characterization of the ovary and oocytes vitellogenesis of the tick Rhipicephalus sanguineus (Latreille, 1806) (Acari : Ixodidae)

This study presents the morphology of the ovary, as well as the process of the vitellogenesis in oocytes of the tick Rhipicephalus sanguineus. The ovary of these individuals is of the panoistic type; therefore, it lacks nurse cells. This organ consists of a single tubular structure, continuous, and composed of a wall formed by small epithelial cells with rounded nuclei which delimit the lumen. The oocytes in the different developmental stages in this tick species were classified into five stages (I V). They remain attached to the ovary during vitellogenesis by a cellular pedicel and afterwards the mature oocytes (stage V) are released into the ovary lumen. (c) 2005 Elsevier B.V. All rights reserved.

Microspines in the pylorus of Pseudonannolene tricolor and Rhinocricus padbergi (Arthropoda, Diplopoda)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ultramorphology and histology of the larval salivary gland of Pachycondyla villosa (Fabricius) (Hymenoptera: Formicidae, Ponerinae)

A glândula salivar apresenta-se com um duto anterior único, formado por um epitélio colunar, dois dutos laterais curtos, os quais apresentam-se com epitélio cúbico simples e que na sua porção mais proximal torna-se colunar. Posterior a estes, encontram-se os dois reservatórios, os quais possuem o epitélio bastante delgado e é neste reservatório que a região secretora da glândula se abre. Os ramos dorsal e ventral da região secretora da glândula conectam-se por meio de comissuras transversais, sendo que, posteriormente, a região secretora termina em forma de alça. A região secretora é uniforme, não apresenta tipos celulares distintos e é formada por um epitélio cúbico simples. Neste trabalho é apresentada, também, a revisão sobre a morfologia da glândula salivar larval em insetos, principalmente com relação aos Hymenoptera-Aculeata.

Ultramorphological features of the egg of Telmatoscopus albipunctatus (Williston) (Diptera, Psychodidae)

Aspectos ultramorfológicos do ovo de Telmatoscopus albipunctatus (Williston) (Diptera, Psychodidae). As moscas da família Psychodidae, também conhecidas como moscas de banheiro, são de importância médica e veterinária. Informações gerais sobre ciclo de vida e hábitos do adulto são facilmente encontradas, mas pouco se sabe sobre a morfologia do ovo. Dessa forma, neste estudo, a ultramofologia do ovo de Telmatoscopus albipunctatus (Williston, 1893) foi analisada por microscopia eletrônica de varredura com o objetivo de descrever sua estrutura, provendo importantes dados para futuras comparações entre moscas de diferentes espécies e gêneros. O aspecto geral do ovo de T. albipunctatus é similar a outros Psychodidae, medindo aproximadamente 0.4 mm de comprimento e 0.1 mm de largura. Entretanto, baseado nas esculturas contínuas e descontínuas do exocórion, as quais podem ser espécie-específicas, podemos inferir que os ovos de T. albipunctatus podem sobreviver sob condições de muita umidade ou seca, dificultando o controle da espécie. Nossos resultados ressaltam a importância do uso da microscopia eletrônica como uma ferramenta no estudo dos padrões do exocórion. A morfologia externa do ovo de T. albipunctatus pode ser usada como base para futuros estudos e como ferramenta para comparação de diferentes espécies de moscas do gênero Psychodidae.