Rearing two fruit flies pests on artificial diet with variable pH / Criação de duas moscas-das-frutas praga em dieta artificial com variação de pH

Abstract Fruit flies (Diptera: Tephritidae) are considered the main fruit pests worldwide. In Brazil, two species are predominant: the South American fruit fly, Anastrepha fraterculus and the Mediterranean fruit fly, Ceratitis capitata. In this study, we evaluated the effect of artificial diets with variable pH in their larval development and adult performance. The experiments were carried out in the laboratory at 25 ± 2 °C, 70 ± 10% RH and 12:12h (L:D) photoperiod. Semisolid diets with pH values of 6.0, 5.0, 4.0, 3.0, 2.0, 1.5, and 1.0, adjusted by adding hydrochloric acid were tested. Results indicated that the diet with pH 6.0 did not support larval development of both species of fruit fly. Diets with greater acidic pH values did not allow egg, larvae or pupae development and adult reproduction of A. fraterculus. For C. capitata , the pH of artificial diet exerts greater influence compared to A. fraterculus on the duration and viability of the larval stage, number of pupae, sex ratio and longevity of males.

Resumo As moscas-das-frutas (Diptera: Tephritidae) são consideradas as principais pragas da fruticultura mundial. No Brasil, duas espécies são predomindantes: a mosca-das-frutas Sul-americana, Anastrepha fraterculus e a mosca-do-Mediterrâneo, Ceratitis capitata. Neste estudo avaliamos o efeito de dietas artificiais com pH variável no seu desenvolvimento larval e performance de adultos. Os experimentos foram realizados em laboratório a 25 ± 2 °C, 70 ± 10% UR e fotoperíodo de 12:12 horas. Foram testadas dietas semi-sólidas com valores de pH de 6,0; 5,0; 4,0; 3,0; 2,0; 1,5 e 1,0, ajustados pela adição de ácido clorídrico. Os resultados indicaram que a dieta com pH 6,0 não suportou o desenvolvimento larval de ambas as espécies de mosca-das-frutas. As dietas com pH ácido não permitiram o desenvolvimento de ovos, larvas ou pupas e a reprodução de adultos de A. fraterculus. Para C. capitata o pH da dieta artificial exerceu maior influência do que para A. fraterculus nos parâmetros de duração e viabilidade do estágio larval, número de pupas, razão sexual e longevidade de machos.

Developmental stages and viability of Toxocara canis eggs outside the host / Desarrollo y viabilidad de huevos de Toxocara canis

ABSTRACT Introduction: Toxocariasis is a soil-transmitted zoonotic disease caused mainly by ingestion of larvated eggs of Toxocara canis. Objectives: To study the morphology of the intraovular developmental stages of Toxocara canis in culture, characterize non-viable eggs and the sequences of larval molting and compare the viability of eggs at the early stages of division and at reaching full maturation. Material and methods: Observation of developing embryos and characterization of non-viable eggs were done using light microscope. The proportions of viable eggs during embryonation were compared to the proportions of viable mature eggs. Results: Cell division commenced after 24 hours of cultivation. Early stages were found to be present over a period of 3-5 days. The developmental stages identified were eggs with: One cell, two cells, three cells, four cells, early morula, late morula, blastula, gastrula, tadpole, pre-larva, first, second and third stage larva. Two larval molts occurred. Non-viable eggs had degenerated cytoplasm, thin or collapsed shell and the larvae did not move after exposure to light. No significant differences were found between the proportions of viable eggs from day five to day 21 as compared to viability of fully mature eggs (30 days). Conclusion: Developing embryos in the environment may be considered as a potential threat to the public health. The precise identification of developmental stages and the clear differentiation of viable and non-viable eggs can help in determining an accurate baseline rate of development that could be used in studies of ovicidal compounds.

RESUMEN Introducción. La toxocariasis es una enfermedad zoonótica transmitida por contacto con el suelo contaminado y causada principalmente por la ingestión de huevos larvados de Toxocara canis. Objetivos. Estudiar la morfología de los estadios intraovulares en desarrollo de T. canis en cultivo, caracterizar los huevos no viables y las secuencias de las mudas larvarias, y comparar la viabilidad de los huevos en las etapas tempranas de división y al alcanzar la maduración completa. Materiales y métodos. Se observó el desarrollo de los embriones y se caracterizaron los huevos no viables, mediante microscopía de luz. Se comparó la proporción de huevos viables con embrión con la de huevos maduros viables. Resultados. La división celular comenzó 24 horas después de iniciado el cultivo. Los estadios tempranos estuvieron presentes por un periodo de tres a cinco días. Los estadios de desarrollo identificados fueron: huevos con una célula, con dos células, con tres células y con cuatro células;mórula temprana, mórula tardía, blástula, gástrula, renacuajo, prelarva, primer, segundo y tercer estado larvario. Se presentaron dos mudas larvarias. Los huevos no viables tenían el citoplasma degradado, cubierta exterior delgada o colapsada, y su larva no se movía al exponerla a la luz. No se encontraron diferencias significativas entre la proporción de huevos viables del día 5 al día 21, al compararla con la viabilidad de los huevos completamente maduros (30 días). Conclusión. Los embriones en desarrollo en el medio ambiente pueden considerarse como un riesgo potencial para la salud pública. La identificación precisa de los estadios de desarrollo y la clara diferenciación de huevos viables y no viables, pueden ayudar a determinar con exactitud una tasa basal de desarrollo, la cual sería útil en el estudio de compuestos ovicidas.

Desove espontáneo, ontogenia y crecimiento en cautiverio de Cynoscion squamipinnis (Perciformes: Sciaenidae) / Spontaneous spawning, ontogeny and growth in captivity of Cynoscion squamipinnis (Perciformes: Sciaenidae)

ResumenLas corvinas son especies de interés comercial que han sido sobreexplotadas en el Golfo de Nicoya, Costa Rica. El objetivo de este estudio fue describir por primera vez, el desove espontáneo y la ontogenia de las larvas de la corvina aguada Cynoscion squamipinnis en cautiverio, con el fin de realizar repoblamiento y proyectos de maricultura. Reproductores silvestres (n= 6, 1-2 Kg), fueron capturados y mantenidos en la Estación de Biología Marina Juan Bertoglia Richards (Puntarenas, Costa Rica) por un periodo de dos años (octubre 2006-diciembre 2008). Durante este periodo, el estado de madurez de las hembras (n= 3) fue registrado mediante muestras de cánula y los machos (n= 3) mediante masaje abdominal. Todos los reproductores fueron colocados juntos en un tanque de 18 t, con aireación, a una salinidad entre 33-35 ups y expuestos a una temperatura constante (29 ± 1 °C). De enero a marzo 2009 ocurrió un periodo de desove espontáneo, obteniéndose 162 000 huevos en tres desoves. El porcentaje de fertilización fue de 50-60 %, y la supervivencia después de la eclosión fue entre 60-85 %. El diámetro de los huevos fue de 0.852 mm (Desviación Estándar= 0.039), con una gota de aceite de 0.269 mm (DE= 0.016). En el desarrollo embrionario, la primera división mitótica ocurrió una hora después del desove (hdd), la segunda división 1:30 hdd, la tercera división 2 hdd, la cuarta división a las 2:30 hdd, y la quinta 3:00 hdd. La mórula fue observada a las 3:30 hdd, la blástula a las 4:30 hdd, la gástrula a las 8:30 hdd, la forma C a las 10:00 hdd, y la forma S ocurrió de las 10-19 hdd. La eclosión ocurrió 19 hdd. La larva midió 2.234 mm (DE= 0.122) de longitud total (LT), y 2.179 mm (DE= 0.119) de longitud notocordial (LN). La preflexión inició 49 hdd, la flexión 11 días después del desove (ddd) (3.767 mm LT, DE= 0.209), y la postflexión a los 14 ddd (4.015 mm LT, DE= 0.302). A los 45 ddd, los juveniles pesaron 3.68 g (DE= 1.09). El tiempo de eclosión de las larvas de la corvina aguada fue menor al de otras especies de corvina. Los tiempos de formación en las etapas embrionarias difirieron poco con respecto a los tiempos observados para otras especies de corvinas. Las diferencias observadas con respecto a otras especies, probablemente responden a las características genéticas propias de cada especie y a la temperatura de incubación de los huevos. La obtención de desoves espontáneos sin aplicaciones hormonales a los reproductores, y la producción de juveniles en cautiverio demostraron que la corvina aguada puede ser considerada en programas de repoblamiento y proyectos de maricultura.

Abstract:The croakers or drums are commercial species, which have been overfished in the Nicoya Gulf, Costa Rica. This study aimed to describe, for the first time, the reproduction and the ontogeny of weakfish, Cynoscion squamipinnis in captivity, in order to perform restocking and mariculture projects. Wild fish (n= 6, 1-2 Kg) were captured and maintained in the Estación de Biología Marina Juan Bertoglia Richards (Puntarenas, Costa Rica) for a two years period (October 2006- December 2008). During this period, maturation stage was monitored periodically by cannula samples in the females (n= 3) and gentle massage in males (n= 3). All fish were stocked in an 18 t tank, with aeration, 33-35 ups of salinity, and a constant temperature (29 ± 1 °C). The spawning period occurred from January to March 2009, producing 162 000 eggs in three spontaneous spawns. The fertilization percentage was 50-60%, and survival after hatching was 60-85%. The egg diameter was 0.852 mm (Standard deviation (SD)= 0.039), and oil drop of 0.269 mm (SD= 0.016). In the embryonary development, the first mitotic division (MD) was observed one hour after spawning (has), the second MD was 1:30 has, the third MD was 2:00 has, the fourth MD was 2:30 has, and fifth MD at 3:00 has. Morule was observed 3:30 has, the blastule 4:30 has, the gastrule 8:30 has, C shape at 10:00 has, and C shape at 12:00 has. After 19 has hatching larvae occurred. The total length (TL) of the larvae was 2.234 mm (SD= 0.122), and the nothochordial length (NL) was 2.179 mm (SD= 0.119). Preflexion stage was observed 49 has, flexion stage was 11 days after spawn (das) (3.767 mm LT (SD= 0.209)), and postflexion stage was 14 das (4.015 mm LT (SD= 0.302)). After 45 das, the juvenile weights 3.68 g (SD= 1.09). Hatch time of the weakfish larvae was minor than of others croaker species. The stages times of embrionary development were a little different from others croaker species, and probably respond to genetic characteristics of each species and the eggs incubation temperature. The spontaneously spawning without broodstock hormonal applications, and the juveniles production in captivity showed that weakfish is a potential species for restocking programs and mariculture projects. Rev. Biol. Trop. 64 (3): 991-1005. Epub 2016 September 01.

Biology and fertility life table of Eriopis connexa, Harmonia axyridis and Olla v-nigrum (Coleoptera: Coccinellidae) / Biologia e tabela de vida de fertilidade de Eriopis connexa, Harmonia axyridis e Olla v-nigrum (Coleoptera: Coccinellidae)

Abstract The coccinellids Eriopis connexa (Germar), Harmonia axyridis (Pallas) and Olla v-nigrum (Mulsant) are important natural biological control agents. The purpose of this paper was to study the biology and create a fertility life table of these three coccinellid species. For the biology study, 50 insects/species were used and kept in groups of 10 in glass vials (2300cm3). For the three species studied, the viability of the total cycle varied from 45 to 50%. O. v-nigrum was the species which presented the longest oviposition period. However, H. axiridis demonstrated the best reproductive performance and ability of population growth in each generation. In conclusion, the use of commercially obtained pollen and A. kuenhiella eggs enables the development of coccinellids E. connexa, H. axyridis and O. v-nigrum under laboratory conditions, since the insects completed their biological cycle and originated adults with good reproductive performance.

Resumo Os coccinelídeos Eriopis connexa (Germar), Harmonia axyridis (Pallas) e Olla v-nigrum (Mulsant) são importantes agentes de controle biológico natural. O objetivo deste trabalho foi estudar a biologia e a tabela de vida de fertilidade dessas três espécies de coccinelídeos. Para a biologia foram utilizados 50 insetos/espécie, mantidos em grupo de 10 em recipientes de vidro de (2300cm3). Para as três espécies estudadas, a viabilidade do ciclo total variou de 45 a 50%. O. v-nigrum foi a espécie que apresentou maior período de oviposição. No entanto, H. axiridis foi àquela que demonstrou maior performance reprodutiva e capacidade de aumento populacional a cada geração. Em conclusão, a utilização de pólen comercial e ovos de A. kuenhiella possibilita o desenvolvimento dos coccinelídeos E. connexa, H. axyridis e O. v-nigrum em condições de laboratório, pois, os insetos completaram o ciclo biológico e originaram adultos com boa performance reprodutiva.

Sarcophaga (Liosarcophaga) dux (Diptera: Sarcophagidae): A flesh fly species of medical importance

BACKGROUND: Although tropical climate of Thailand is suitably endowed with biodiversity of insects, flies of medical importance is not well investigated. Using information from literature search, fly survey approach and specialist's experience, we review database of Sarcophaga (Liosarcophaga) dux Thomson (Diptera: Sarcophagidae), one of the priorities flesh fly species of medical importance in Thailand. RESULTS: This review deals with morphology, bionomics and medical involvement. Important morphological characteristics of egg, larva, puparia and adult were highlighted with illustration and/or micrographs. Search pertaining to molecular analysis used for fly identification and developmental rate of larvae were included. Medical involvement of larvae was not only myiasis-producing agent in humans and animals, but associated with human death investigations. CONCLUSIONS: This information will enable us to accurate identify this species and to emphasis the increase medically important scene in Thailand.

Effectiveness of Asteraceae extracts on Trichostrongylidae eggs development in sheep / Eficácia de extratos da família Asteraceae no desenvolvimento dos ovos de Trichostrongilídeos de ovinos

Data on in vitro evaluation of extracts of three species of the Asteraceae family on the development of Trichostrongylidae eggs in sheep are presented. Egg hatchability was tested using herbal extracts prepared in a Soxhlet extractor, and using hydrolate prepared by means of hydrodistillation. The laboratory tests showed that the ethanol extract from flowers of the species Aster lanceolatus presented high activity against Trichostrongylidae eggs development in sheep, inhibiting larva formation by 91 percent within 48 hours, and maintaining similar rates after 72 hours.

Apresentam-se dados da avaliação in vitro de três espécies vegetais da família Asteraceae sobre o desenvolvimento dos ovos de Trichostrongilídeos de ovinos. Realizou-se o teste de eclodibilidade com extratos vegetais preparados por aparelho de Soxhlet e hidrolato preparado por hidrodestilação. Os testes laboratoriais evidenciaram que o extrato etanólico das flores da espécie Aster lanceolatus apresenta alta atividade sobre o desenvolvimento dos ovos de Trichostrongilídeos de ovinos, inibindo em 91 por cento a formação da larva em 48 horas, mantendo-se índices próximos em 72 horas.

[Effect of post-ovulatory oocyte retention in abdominal cavity on egg quality and its histological changes in caspian brown trout [Salmo Trutta Caspius]]

Determination of the accurate time of egg stripping after ovulation has been regarded as one of the most important factors in the successful reproduction of Caspian brown trout[Salmo trutta caspius]. To determine the best time for egg stripping after ovulation and over-ripening of the oocyte in the Caspian brown trout, the eggs of fish were retained in the coelomic cavity of females at 7 +/- 6°C over 40 days of post-ovulation[DPO]. Eggs were stripped at 10 day intervals in 4 stages and then were fertilized with the mixed milt of males. The obtained results showed that the eyeing rate decreased from 90.65 +/- 6.28% in newly ovulated eggs [0-10 DPO]to 0.67 +/- 1.34% in over-ripened eggs[30-4ODPO]. Also, the hatching rate decreased from 86.33 +/- 6.28% in newly ovulated eggs to 0.49 +/- 0.98% in over-ripened eggs. However, larval abnormalities remained constant for 30 days after ovulation. The histological study in the newly ovulated egg showed that the yolk consisted of homogenous tissue having the perivitelline space diameter with no considerable difference. At over-ripening stage, the yolk became hetero generous, while chorion diameter did not change. Also the perivitelline space diameter varied among different areas. The micropylar apparatus also showed no change during the over-ripening stage. The present study demonstrated that the best time to strip Caspian brown trout eggs post-ovulation was up to 10 DPO at 7 +/- 0.6°C. Same histological changes occurred in oocyte at over-ripening hut it showed no effect on the micropyle

Fecundity, growth, and survival of the angelfish Pterophyllum scalare (Perciformes: Cichlidae) under laboratory conditions

The freshwater angelfishes (Pterophyllum) are South American cichlids that have become very popular among aquarists, yet scarce information on their culture and aquarium husbandry exists. We studied Pterophyllum scalare to analyze dietary effects on fecundity, growth, and survival of eggs and larvae during 135 days. Three diets were used: A) decapsulated cysts of Artemia, B) commercial dry fish food, and C) a mix diet of the rotifer Brachionus plicatilis and the cladoceran Daphnia magna. The initial larval density was 100 organisms in each 40L aquarium. With diet A, larvae reached a maximum weight of 3.80g, a total length of 6.3 cm, and a height of 5.8cm; with diet B: 2.80g, 4.81cm, and 4.79cm, and with diet C: 3.00g, 5.15cm, and 5.10cm, respectively. Significant differences were observed between diet A, and diet B and C, but no significantly differences were observed between diets B and C. Fecundity varied from 234 to 1 082 eggs in 20 and 50g females, respectively. Egg survival ranged from 87.4% up to 100%, and larvae survival (80 larvae/40L aquarium) from 50% to 66.3% using diet B and A, respectively. Live food was better for growing fish than the commercial balanced food diet. Fecundity and survival are important factors in planning a good production of angelfish. Rev. Biol. Trop. 57 (3): 741-747. Epub 2009 September 30.

Se realizaron estudios de cultivo en laboratorio del pez ángel, Pterophyllum scalare, para analizar los efectos de su dieta en la fecundidad, crecimiento y sobrevivencia en huevos y larvas por un período 135 días. Tres dietas diferentes se utilizaron A) quistes decapsulados de Artemia, B) comida comercial seca para pez, C) una mezcla de rotíferos, Brachionus plicatilis y el cladocero, Daphnia magna. La densidad inicial de larvas en acuarios de 40L fue de 100 organismos. Utilizando la dieta A, las larvas alcanzaron un peso máximo de 3.80g, una longitud total de 6.3cm y una altura de 5.8cm; utilizando la dieta B, fue de 2.80g, 4.81cm y 4.79cm y con la dieta C, fue de 3.00g, 5.15cm y 5.10cm, respectivamente. Diferencias significativas se observaron entre la dieta A y las dietas B y C. La fecundidad varió de 234 a 1082 huevos en hembras de 20 y 50g, respectivamente. La sobrevivencia de los huevos varió de 87.4% a 100% y la sobrevivencia de las larvas (80 larvas por acuario de 40L) varió entre 50 y 66.3% con las dietas B y A, respectivamente. Los resultados indicaron, que la comida viva fue mejor para el crecimiento de los peces, que los alimentados con la comida comercial balanceada. La fecundidad y la sobrevivencia son factores importantes para la planificación de una buena producción del pez ángel.

Desarrollo embrionario-larval del pez tropical Hemirhamphus brasiliensis (Beloniformes: Hemirhamphidae) a partir de huevos recolectados del medio natural

Embrionary-larval development of the tropical fish Hemirhamphus brasiliensis (Beloniformes: Hemirhamphidae) from eggs collected in the wild. The embryo formation and larval development of Hemirhamphus brasiliensis Linnaeus, 1758 (Pisces: Hemirhamphidae) is described from morula stage eggs collected on Sargassum sp. Thalii in the field (10°50’55.2" N y 64°09’467" W). The eggs were spherical, 1 923.54 ±72.35 µm diameter with several corionic filaments, and are striated. During the first 48 h the embryo developed cephalic vesicle, miomers, and a heart located on the external body surface, beating strongly and circulating colorless blood which became pigmented red later. Before hatching, the larva developed kidney, gut tract, liver and biliar vesicle, pectoral fins, four pairs of gill arches and the mouth. The larva hatched at 114 h, the body was torpedo-shaped, yellow-green, with several dendriform melanophores; the pelvic fin was observed 72 h post hatching. At 240 hours the metamorphoses was completed. When the larvae hatched they could ingest Artemia metanauplii. Rev. Biol. Trop. 56 (3): 1449-1458. Epub 2008 September 30.

Se describe la formación del embrión y el desarrollo larval del pez Hemirhamphus brasiliensis Linnaeus, 1758, a partir de huevos en estado de mórula, recolectados en el alga parda Sargassum sp. Los huevos eran esféricos con un diámetro de 1923.54 ±72.35 µm, con numerosos filamentos coriónicos y estrías en su superficie. Durante las primeras 48 h, el embrión desarrolló la vesícula cefálica, los miomeros y el corazón, el cual se ubicó en el exterior de cuerpo impulsando sangre incolora, la cual se pigmentó de rojo posteriormente. Antes de la eclosión se desarrollaron el riñón, estómago, hígado y la vesícula biliar, las aletas pectorales, cuatro pares de arcos branquiales y la boca. Las larvas eclosionaron a la 114 h, presentando el cuerpo robusto en forma de torpedo, verde-amarillo con melanoforos dendriformes. Al nacer ingirieron metanauplios de Artemia. A las 72 h después de la eclosión se observó el esbozo de la aleta pélvica y a las 240 h se completó la metamorfosis.

Influence of ambient ultraviolet radiation on Bufo calamita egg development in a semiarid zone (Catalonia, Spain).

Several experiments have shown that ambient ultraviolet-B radiation (UV-B) has negative effects on the development of amphibians' embryos. We studied the effects of UV-B radiation on development, survival and frequency of deformity during egg development in the Natterjack toad (Bufo calamita) from a semiarid region of Lleida (Catalonia, Spain). Eggs exposed to ambient levels of UV-B and those protected from UV-B with a filter exhibited similar developmental rate, mortality rate and frequency of developmental anomalies. These experiments show that eggs of Bufo calamita of the studied population are able to develop normally during embryonic period when exposed to current high levels of UV-B observed in Catalonia. These results will be used as reference for future studies on geographic variation in UV-B tolerance in this species.

Patterns of investment of the reproductive strategy of two stream-dwelling Characidae

The reproductive strategy of two congeneric species (Astyanax janeiroensis - AJ and Astyanax hastatus - AH) was assessed, in order to address the costs imposed by different investment patterns, on four major life history characters: migratory behaviour, breeding time, fecundity and egg size. Altitudinal segregation of young and adult individuals plus data from the literature indicated that AJ is a migratory species, whereas AH is non migratory. Breeding season (BS) analysis revealed that AH was reproductively active year-round (12 months), whereas AJ breeds during 9 months. Brood costs (Ovarian Investment) were almost the same for both species (AJ - 364 oocytes / g and egg volume = 0.52 mm³; AH -702 oocytes / g and egg volume = 0.27 mm³). Reproductive costs (RC), considered as product of gamete production (OI) and gamete output (BS), were 1,703.7 for AJ and 2,274.0 for AH; thus RC is 25 percent higher in AH. It is concluded that the costs with OI (egg size and egg numbers) are equal for both species but as breeding season is larger for AH the overall strategy is 25 percent more expensive in AH. Thus, it is hypothesized that this 25 percent should be considered as the extra costs that AJ uses during migration and is compensated by its shorter breeding time (9 months versus 12 months of AH).

A estratégia reprodutiva de duas espécies congenéricas (Astyanax janeiroensis - AJ e Astyanax hastatus - AH) foi analisada a fim de se determinar os custos energéticos impostos por diferentes padrões de investimento em quatro dos principais caracteres da história de vida de peixes: comportamento migratório, estação reprodutiva, fecundidade e tamanho dos ovócitos. A segregação espacial dos indivíduos jovens e adultos associada a informações da literatura indicaram que AJ é uma espécie migratória enquanto AH não migra. A análise sobre a estação reprodutiva (ER) revelou que AH se reproduz ao longo de todo o ciclo anual (12 meses) enquanto AJ se reproduz durante 9 meses. Os custos com a desova (Investimento Ovariano - IO) foram similares nas duas espécies (AJ - 364 ovócitos/g e volume dos ovócitos = 0,52 mm³; AH - 702 ovócitos/g e volume dos ovócitos = 0,27 mm³). O custo da reprodução (CR), considerado como o produto da produção de gametas (IO) e o tempo de liberação dos gametas (ER), foram 1.703,7 para AJ e 2.274,0 para AH; assim CR é 25 por cento superior em AH. Concluímos assim, que os custos com IO (tamanho e número de ovócitos) são iguais para as duas espécies, mas como a estação reprodutiva é maior para AH, a estratégia como um todo é mais custosa para AH. Dessa forma, sugerimos que os 25 por cento excedentes podem ser considerados como os custos extras que AJ necessita para a migração e são compensados pelo menor tempo da estação reprodutiva (9 meses em AJ versus 12 meses em AH).

Obtención de masas ovígeras del caracol lancetilla, Strombus pugilis (Mesogastropoda: Strombidae) en condiciones de laboratorio / Obtaining of egg masses of the snail, Strombus pugilis (Mesogastropoda: Strombidae) under laboratory conditions

The survival, reproduction and embryonic development of Strombus pugilis, were determined during a period of ten months under laboratory conditions. Seven progenitors were collected in Contoy Island, Quintana Roo, Mexico and later transferred to the laboratory, where they were placed in aquarium with 80 1 of sea water and fed with "pellets". A total of 30 egg masses were collected, one on September and the other on April. The estimated total length of one egg mass was 11.24 m; the mean number of embryos obtained per 2 cm was 264, obtaining an estimated total of 157 500 embryos in the egg mass. The means of the physical-chemical parameters during the study were: salinity 37.6 +/- 0.5% per hundred, pH 7.5 +/- 0.5 and temperature 28 +/- 0.2 degrees C. The maintenance and water recirculation system used to sustain the breading stock is excellent both for reproduction of the organism and for obtaining egg masses under controlled conditions.

First description of the immature stages of Hemilucilia segmentaria (Diptera: Calliphoridae)

The immature stages oí Hemilucilia segmentaria (Fabricius, 1805) (Diptera: Calliphoridae) are described. Egg morphology and structures such as the cephalopharyngeal skeleton, anterior and posterior spiracles, and the dorsal spines between the prothorax and mesothorax from first, second and third instar larvae are characterized, using light and scanning electron microscopy. This species is abundant in Neotropical forests and, because of its necrophagous behavior, is of substantial medico-legal importance for estimating the postmortem interval in criminal investigations. Information presented herein may be useful to differentiate among eggs and larvae of closely related species and to supplement the database for blowfly identification.

Comparative morphology of reproductive and trophic eggs in melipona bees (Apidae, Meliponini)

The process of cell provisioning and oviposition (POP) in stingless bees involves highly complex interactionsbetween the queen and workers. During this process, workers can usually lay two types of eggs, referred toas reproductive and trophic. Reproductive worker-laid eggs are unfertilized but develop into males whereastrophic worker-laid eggs are eaten by the queen immediately after oviposition. Although the egg-layingactivity of reproductive workers varies considerably among species, the laying of trophic eggs appears to bethe rule in Melipona bees. In this work, we examined whether the morphology of eggs laid by workers andqueens of M. scutellaris, M. compressipes fasciculata and M. asilvai was similar to that of other Meliponaspecies. Egg morphology was examined by scanning electron microscopy whereas egg size was measured bylight microscopy. In all of the species studied, the chorion of queen and worker reproductive eggs showed acharacteristic reticulate pattern. The surface of trophic eggs was not reticulate and had an irregular appearancefollowing fixation. Trophic eggs were also invariably smaller than queen-laid eggs and were sometimessmaller than worker-laid reproductive eggs. These findings indicate that trophic eggs can be smaller than theeggs of functional workers, which suggests that the development of this type of egg is probably associatedwith different physiological adaptations.

Embryonic and larval development of Jundiá (Rhamdia quelen, Quoy & Gaimard, 1824, Pisces, Teleostei), a South American Catfish

The jundiá (Rhamdia quelen, Quoy & Gaimard) is an endemic South American fish species. Because this species supports cold winters and grows faster during warm months, it has begun to be viewed as an ideal species for fish production in southern South America. In the present study, jundiá oocytes used were obtained by extrusion from females after hormone injection. Soon after hydration, the eggs were transferred to 50 L conic glass incubators, with constant and controlled water influx. Samples of fertilized eggs were transferred to Petri dishes and, examined under a stereoscopic microscope, were spherical, demersal, and non-adhesive with defined perivitelline space and resistant chorion. Cleavage stages occurred during the first 3.5 h. After hatching, larvae were transferred to 200 L glass fiber incubators. First signs of embryo movement were observed 21 h after fertilization; larval eclosion occurred 30.5 h after fertilization. Present findings may provide a basis for studies aimed at determining the complete ontogeny of jundiá and may be useful in eco-toxicological studies.

O jundiá (Rhamdia quelen, Quoy & Gaimard) é uma espécie endêmica da América do Sul. Por ser adaptada ao frio do inverno e ter um crescimento rápido durante os meses quentes, o jundiá é uma espécie adequada para aqüicultura no sul da América do Sul. Muitos aspectos da fisiologia reprodutiva, larvicultura, hematologia, fisiologia da resposta ao estresse, têm sido recentemente estudados. Os ovócitos utilizados neste estudo foram obtidos pela extrusão de fêmeas após indução hormonal. Logo após a hidratação, foram transferidos para incubadoras cônicas de vidro com capacidade para 50 L, com fluxo de água constante e controlado. Amostras de ovos fertilizados foram colocadas em placas de Petri e examinadas através de estereomicroscópio. Os ovos eram esféricos, demersais e não-adesivos, com espaço perivitelino definido e córion resistente. Os estágios de clivagem ocorreram durante as 3,5 primeiras horas. Após a eclosão, as larvas foram transferidas para incubadoras de fibra de vidro de 200 l. Os primeiros sinais de movimento embrionário foram observados 21 h após a fertilização, e a eclosão das larvas ocorreu 30,5 h após a fertilização. Estes resultados podem servir como base para muitos estudos, objetivando o conhecimento da ontogenia completa do jundiá, e para aplicação em estudos ecotoxicológicos.

Comparison between morphological and staining characteristics of live and dead eggs of Schistosoma mansoni

Schistosoma mansoni eggs are classified, according to morphological characteristics, as follows: viable mature and immature eggs; dead mature and immature eggs, shells and granulomas. The scope of this study was to compare the staining characteristics of different morphological types of eggs in the presence of fluorescent labels and vital dyes, aiming at differentiating live and dead eggs. The eggs were obtained from the intestines of infected mice, and put into saline 0.85 percent. The fluorescent labels were Hoechst 33258 and Acridine Orange + Ethidium Bromide and vital dyes (Trypan Blue 0.4 percent and Neutral Red 1 percent). When labelled with the probe Hoechst 33258, some immature eggs, morphologically considered viable, presented fluorescence (a staining characteristic detected only in dead eggs); mature eggs did not present fluorescence, and the other types of dead eggs, morphologically defined, showed fluorescence. As far as Acridine Orange + Ethidium Bromide are concerned, either the eggs considered to be live, or the dead ones, presented staining with green color, and only the hatched and motionless miracidium was stained with an orange color. Trypan Blue was not able to stain the eggs, considered to be dead but only dead miracidia which had emerged out of the shell. Neutral Red stained both live and dead eggs. Only the fluorescent Hoechst 33258 can be considered a useful tool for differentiation between dead and live eggs.

Estudo biológico e biométrico dos estádios ninfais de Rhodnius prolixus Stãl, 1859 (Hemiptera, Reduviidae) sob condições laboratoriais / Biological and biometric studies of the nymph instars of R. prolixus (Hemiptera, Reduviidae)

A partir de ninfas de 5o estádio obtiveram-se casais de Rhodnius prolixus, que originaram ovos e ninfas para estudos de ciclo biológico e biométrico. Foram determinados os seguintes parâmetros do ciclo biológico à temperatura de 28OC e umidade relativa do ar variando entre 52 e 94%: período médio de incubação dos ovos: 13,01 dias; taxa de eclosão dos ovos: 77,6%; período médio de desenvolvimento do 1º, 2º, 3º, 4º e 5º estádio ninfal: 19, 33;19,09; 20,38; 24,37; 38,14 dias, respectivamente;percentual de mortes nos estádios ninfais: 26,70; 14,00;18,26; 17,02; 35,47% respectivamente; percentual de mudas por estádio ninfal; 73,30; 86,03; 81,73; 82,97 e 64,52%, respectivamente. Estudo biométrico mostrou que o abdômen é o maior segmento em todos os estádios. Nos quatro primeiros estádios a cabeça apresenta-se maior que o tórax, enquanto no quinto estádio a cabeça e o tórax apresentam portes equivalentes.

Teste de toxicidade e criopreservação de folículos pré-antrais ovinos isolados utilizando Glicerol, Etilenoglicol, Dimetilsulfóxido e Propanodiol / Toxicity test and cryopreservation of sheep isolated preantral follicles using glycerol, ethylen glycol, dimethil sulfoxyde and propanediol

O objetivo deste estudo foi avaliar foliculos pré-antrais (FOPA) ovinos isolados após sua exposição e criopreservação utilizando glicerol (GLI), etilenoglicol (EG), propanodiol (PROH) ou dimetilsulfóxido (DMSO) a 1,5 e 3,0 M. Cada par ovariano de 5 ovelhas sem raça definida foi coletado em abatedouro local e submetido ao isolamento folicular. Da suspensão obtida, uma aliquota foi imediatamente destinada à análise da viabilidade folicular com o auxílio do corante vital azul de trypan. O restante da suspensão foi dividida em 16 aliquotas de 0,9 mL, suspensas (v/v) em MEM+ com EG, DMSO, GLI ou PROH a 1,5 ou 3,0 M, para teste de toxicidade e criopreservação. Após o término de cada tratamento, a viabilidade folicular foi analisada e os FOPA considerados viáveis se não corados ou não viáveis, quando corados. A análise dos dados mostrou que após o teste de toxicidade e criopreservação, em todos os crioprotetores e em ambas as concentrações, a percentagem de FOPA viáveis foi significativamente reduzida quando comparada ao controle. No teste de toxicidade, quando os crioprotetores foram comparados entre si nas mesmas concentrações, foram observadas percentagens signifIcativamente menores de FOPA viáveis no PROH 3,0 M (38,9%), apresentando-se, portanto, mais tóxico quando comparado aos demais crioprotetores. Após criopreservação, obteve-se percentagens significativamente maiores de foliculos pré-antrais viáveis quando o EG e o DMSO foram utilizados. Em conclusão, FOPA ovinos isolados podem ser criopreservados com sucesso utilizando-se D MSO e EG a 1,5 e 3,0 M.

The aim of this study was to evaluate isolated sheep preantral follicles (PF) after exposure and cryopreservation using glycerol (GLI), ethylene glycol (EG), propanediol (PROH) or dimethyl sulfoxide (DMSO) at 1.5 and 3.0 M. Each ovarian pair from 5 mixed breed adult sheeps was obtained at a local slaughterhouse and submited to follicular isolation. From the obtained suspension, one aliquot was immediately analysed with trypan blue. The remaining suspension was divided in 16 aliquots of 0.9 mL, suspended in (v /v) in MEM+with EG, DMSO, GLI or PROH at 1.5 or 3.0 M to the toxicity test and cryopreservation. After the end of each treatment, the follicular viability was analysed and the PF were classified as viable if not dyed or not viable if dyed with trypan blue. The analysis of the results showed that after the toxicity test and cryopreservation, using all cryoprotectants and at both concentrations, the percentage of viable PF was significandy reduced when compared to the control. At the toxicity test, when the cryoprotectants were compared at the same concentrations, the lowest percentage of viable preantral follicles was obtained when 3.0 M PRO H (38,9%) was used, being, more toxic when compared to the others cryoprotectants. After cryopreservation, significantly higher percentual of viable PF was observed when the EG and DMSO were used. In conclusion, sheep PF can be cryopreserved successfully using DMSO and EG at 1.5 and 3.0 M.