Reproductive Tactics of Sexes and Fitness in the Dragonfly, Diastatops obscura

The sexual selection strategies of territorial Odonata that do not present courtship behavior is still not completely understood, especially the role of the females. Diastatops obscura Fabricius (Odonata: Libellulidae) females participate in mate selection in a passive manner, allowing copulation with the first male that captures them and afterwards choosing whether to oviposit or not. This study introduces the idea of female passive choice as an adaptative tactic in intersexual selection. Also discussed is the adaptative value of this tactic and its flexibility according to environmental conditions and reproductive strategies adopted by the males. A natural population of Diastatops obscura was observed in the Pitimbu River of northeast Brazil. Focal continuous and ad libitum techniques were used to record attempted copulation, copulation, and oviposition behavior, in addition to registering male territoriality. An estimate of individual reproductive success (IRS) was obtained by recording 187 reproductive events. Territorial males, mainly occupying areas near the river margin, achieved greater copulation and oviposition success (IRS = 0.371) than did satellite males (IRS = 0.028). Females that copulated with territorial males experienced, for the most part, only one copulation and oviposition event, while those that copulated with satellite males fled or performed a second copulation with a territorial male. Thus, the best tactic adopted by the D. obscura males was to occupy a territory providing the greatest access to females, while the females used passive choice for fitness optimization

Monkey see, monkey feel? Marmoset reactions towards conspecifics' arousal

Consolation has been observed in several species, including marmoset monkeys, but it is often unclear to what extent they are empathy-based. Marmosets perform well in at least two of three components of empathy-based consolation, namely understanding others and prosociality, but it is unknown to what extent they show matching with others. We, therefore, tested whether non-aroused individuals would become aroused themselves when encountering an aroused group member (indicated by piloerection of the tail). We found a robust contagion effect: group members were more likely to show piloerection themselves after having encountered an aroused versus relaxed conspecific. Moreover, group members offered consolation behaviours (affiliative approaches) towards the aroused fellow group members rather than the latter requesting it. Importantly, this pattern was shown by both aroused and non-aroused individuals, which suggests that they did not do this to reduce their own arousal but rather to console the individual in distress. We conclude that marmosets have all three components of empathy-based consolation. These results are in line with observations in another cooperative breeder, the prairie vole

REPRODUCTIVE BIOLOGY OF MARBLED SWAMP EEL, Synbranchus marmoratus BLOCH, 1975 IN GARGALHEIRAS RESERVOIR, RIO GRANDE DO NORTE, BRAZIL

A biologia reprodutiva do peixe hermafrodita mussum, Synbranchus marmoratus (Bloch, 1795) (Osteichthyes: Synbranchidae) foi investigada no açude Marechal Dutra, Acari, Rio Grande do Norte, utilizando os exemplares capturados mensalmente no período de julho de 2010 á janeiro de 2011. Os peixes capturados foram numerados, pesados, medidos, dissecados as e gônadas foram retiradas, pesadas e identificadas quanto ao sexo. A relação peso-comprimento foi determinada para sexos agrupados. O índice gonadossomático (IGS) e o fator de condição (K) foram verificados. As fases do desenvolvimento das gônadas foram investigadas usando técnicas macroscópicas. As características macroscópicas do desenvolvimento gonadal mostraram quatro tipos sexuais diferentes na população dos peixes capturados, sendo: machos primários, fêmeas, intersexos e machos secundários. As fêmeas foram mais frequentes durante todo o período de estudo (74%). A espécie mostrou um crescimento do tipo alométrico negativo, com maior incremento em comprimento do que em peso. O fator de condição mostrou seu menor valor no mês de agosto e dois picos sendo, um em dezembro de 2010 e outro em janeiro de 2011. O IGS indicou um período reprodutivo que vai de julho a agosto de 2010, mostrando correlação negativa ao fator de condição. S. marmoratus mostra uma estratégia reprodutiva sazonal que aperfeiçoa seu sucesso reprodutivo dentro das condições climáticas do semiárido.Palavras-chave: Symbranchus marmoratus, índice gonadossomático, fator de condição, aspectos gônadais, açúde semiárido.The Reproductive biology of the hermaphrodite fish the marbled swamp eel, Synbranchus marmoratus (Bloch, 1795) (Osteichthyes: Synbranchidae) was investigated in the Marechal Dutra reservoir, Acari, Rio Grande do Norte, using samples captured monthly during the period of July 2010 to July 2011. The captured fish specimens were numbered, weighed, measured, dissected and their gonads was removed, weighed and identified as to sex and developmental stages of gonads. The length-weight relationship was determined for grouped sex. The gonadosomatic index (GSI) and condition factor (K) were calculated. The developmental stages of the gonads were investigated using macroscopic techniques. The macroscopic characteristics of gonadal development showed four different sexual types in the sampled population: primary males, females, transitional individuals and secondary males. Females were more frequent during the entire study period. This species showed a negative allometric growth with a higher increase in length than weight. The condition factor showed its lowest value in August and showed two peak values in December 2010 and in January 2011. The GSI indicated a reproductive period from July to august 2010 and was negatively correlated with the condition factor. S. marmoratus presents a seasonal reproductive strategy which optimizes its reproductive success under the semiarid climatic conditions.Keywords: Synbranchus marmoratus; gonadosomatic index; condition factor; gonadal aspects; semiarid reservoir

FEEDING AND REPRODUCTIVE ASPECTS OF THE FISH Hypostomus pusarum (STARKS, 1913) (OSTEICHTHYES: LORICARIIDAE) IN MARECHAL DUTRA RESERVOIR, RIO GRANDE DO NORTE, BRAZIL

O peixe cascudo, Hypostomus pusarum é de importância ecológica e econômica dos ecossistemas aquáticos da região neotropical. O presente estudo verificou os aspectos alimentares e reprodutivos dessa espécie no açude Marechal Dutra, Acari, Rio Grande do Norte. As capturas dos peixes foram realizadas durante o período de julho de 2011 a junho de 2012, com o auxílio de pecadores locais, que utilizaram redes de espera e tarrafas. Os itens alimentares do estômago de H. pusarum foram identificados até o nível taxonômico mais inferior possível. Foi capturado um total de 118 exemplares de H. pusarum e no laboratório eles foram numerados, pesados, medidos, dissecados e o sexo foi identificado. Foram verificadas a proporção sexual, a relação peso-comprimento, o conteúdo estomacal, o índice gonadossomático (IGS), o fator de condição (K), a fecundidade e o período reprodutivo de H. pusarum. Houve uma predominância de fêmeas (n=67; 55,3%) sobre os machos (n=51; 44,7%). H. pusarum apresenta um crescimento do tipo alométrico negativo, ganhando mais incremento em comprimento do que em peso. A espécie em estudo apresentou uma dieta baseada em material orgânico em decomposição (88,7%) e microalgas (11,3%) consistindo de Bacilariofíceas, Clorofíceas e Cianobacteria. O índice gonadossomático (IGS) dos machos variou de 0,483 a 7,502 e das fêmeas de 3,408 a 10,533. A média do fator de condição (K) dos machos foi de 0,089 e das fêmeas foi de 0,266. A fecundidade absoluta apresentou a média de 756,85. Os peixes apresentaram gônadas em várias fases de maturação durante o período de estudo e a caracterização macroscópica das gônadas indicou quatro estádios de maturação, sendo imaturo, em maturação, maduro e esvaziado. O período reprodutivo de H. pusarum foi indicado pelo pico de IGS durante janeiro a abril.Palavras-chave: Alimentação, reprodução, Hypostomus pusarum, açude Marechal Dutra.The armoured catfish, Hypostomus pusarum is of ecological and economical importance in the neotropical aquatic ecosystems. The present study verified the feeding and reproductive aspects of this species in Marechal Dutra reservoir, Rio Grande do Norte. Fish samples were captured during the period of July, 2011 to June, 2012 with the help local fishermen, who utilized gillnets and cast nets. The food items contained in the stomach of H. pusarum were identified to the lowest possible taxonomic level. A total of 118 individuals of H. pusarum were captured, in the laboratory they were numbered, weighed, measured, dissected and the sex was identified. The sex ratio, length-weight relationship, stomach contents, gonadossomatic index (GSI), condition factor (K), fecundity and reproductive period of H. pusarum were verified. There was a predominance of females (n=67; 55,3%) over the males (n=51; 44,7%). H. pusarum presents a negative a type of growth (negative allometry) with a higher increase in total length than in body weight. The study species showed a diet based on decaying organic matter (88.7%) and microalgae (11.3%), consisting of Chlorophyta, Bacillariophyta and Cyanobacteria, confirming a detritivore/herbivore food habit. The gonadossomatic index (GSI) of males varied from 0.483 to 7.502 and that of females from 3.408 to 10.533. The mean value of condition factor (K) of males was 0.089 and that of females was 0.266. The mean absolute fecundity was 756.85. The fish had gonads in different developmental stages throughout the study period, and the macroscopic characterization of the gonads indicated indicted four stages of development, immature, maturing, mature and spent. The reproductive period of H. pusarum during January to April was indicated by the peak of GSI.Keywords: Feeding; reproduction; Hypostomus pusarum; Marechal Dutra reservoir

COMPARATIVE MORPHOLOGY OF THE DIGESTIVE TRACT OF THE FISHES Hoplias malabaricus AND Hypostomus pusarum IN MARECHAL DUTRA RESERVOIR, RIO GRANDE DO NORTE, BRAZIL

A traíra, Hoplias malabaricus e o cascudo, Hypostomus pusarum são espécies de peixes que apresentam importância ecológica e econômica nos ecossistemas aquáticos neotropicais. O presente trabalho comparou os aspectos morfológicos do trato digestório de H. malabaricus e H. pusarum, relacionando-os com seu hábito alimentar. No período de julho de 2011 a junho de 2012, foram capturados 45 espécimes de H. malabaricus e 33 de H. pusarum, utilizando-se rede de espera e tarrafa no açude Marechal Dutra, Acari, RN. Foram obtidos de cada exemplar o comprimento total e peso do corpo. A posição da boca, presença e tipo dos dentes, número de rastros branquiais, esôfago, forma do estômago e presença de cecos pilóricos foram observados para a descrição morfológica. O comprimento intestinal foi verificado e o conteúdo estomacal foi identificado até o nível taxonômico mais inferior possível. A boca e os dentes de H. malabaricus são adaptados para agarrar e ingerir grandes presas inteiras, enquanto de H. pusarum são adaptados para raspagem. O primeiro o arco branquial de H. malabaricus possui em média sete rastros branquiais afastados entre si, curtos e pontiagudos, mas H. pusarum não apresenta rastros brânquias. A disposição dos órgãos digestórios em ambas as espécies está diretamente relacionada com a forma da cavidade peritoneal e o formato do corpo. H. malabaricus apresenta um intestino curto, porém H. pusarum mostra um intestino muito longo. H. malabaricus alimentou-se de material animal, preferencialmente de peixes (72,8%) e camarões (27,2%), enquanto a dieta de H. pusarum foi baseada em material orgânico em decomposição (88,7%) e microalgas (11,3%). A morfologia do trato digestório e o conteúdo estomacal de H. malabaricus indica hábito alimentar carnívoro, e de H. pusarum confirma seu hábito alimentar detritívoro/herbívoro.Palavras-chave: aspectos morfológicos, trato digestório, dieta, Hoplias malabaricus, Hypostomus pusarum.Hoplias malabaricus and Hypostomus pusarum are fish species which are of ecological and economical importance in the neotropical aquatic ecosystems. The present work compares the morphological aspects of the digestive tract of H. malabaricus and H. pusarum, in relation to their feeding habits. During the period July, 2011 to June, 2012, 45 individuals of H. malabaricus and 33 of H. pusarum were captured, using gillnets and cast nets in the Marechal Dutra reservoir, Acari, RN. Each individual was measured for total length and body weight was obtained. The position of the mouth, presence and type of teeth, number of gill rakers, esophagus, stomach and the presence of pyloric caeca were observed for morphological description. The intestinal length was checked and stomach contents were identified to the lowest possible taxonomic level. The mouth and teeth of H. malabaricus are adapted to grab and swallow large prey, while that of H. pusarum are adapted for scraping. The first branchial arch of H. malabaricus has seven gill rakers, which are spaced, short and sharp, but H. pusarum has no gill rakers. The arrangement of the digestive organs in both species is directly related to the shape of the peritoneal cavity and body shape. H. malabaricus has a short intestine, while H. pusarum presents a very long intestine. . H. malabaricus feeds on animal material, preferably fish (72.8%) and prawns (27.2%), while the diet of H. pusarum constituted mainly of decaying organic matter (88.7%) and microalgas (11.3%). The morphology of the digestive tract and the stomach contents of H. malabaricus indicte a carnivorous food habit and that of H. pusarum confirms a detritivore / herbivore food habit.Keywords: Morphological aspects, digestive tract, diet, Hoplias malabaricus, Hypostomus pusarum

The Temporal Pattern of Mating Behavior of the Fruit Fly, Anastrepha zenildae in the Laboratory

The state of Rio Grande do Norte is an important fruit-producing and exporting area in northeastern Brazil. The success of this industry depends on fruit fly population control, especially in fly-free exporting zones. However, many fruits are not exported because of quarantine restrictions imposed by importing countries. A survey in the state has detected a considerable increase of the fruit fly, Anastrepha zenildae Zucchi (Diptera: Tephritidae), probably a result of the introduction of irrigated guava orchards that make fruit available all year. Knowledge of the sexual behavior of Tephritidae has great importance to pest control programs, particularly those that employ the Sterile Insect Technique. In order to characterize the reproductive behavior of A. zenildae, 32 individuals (16 males; 16 females) in each of six generations were submitted to an artificial 12:12 L:D cycle (750: < 1 lux, lights on 07:00–19:00) and observed over their lifetimes. The courtship and copulation occurred in leks and the episodes varied with the time of day, courtship being most frequent between Zeitgeber time (ZT) 3 and ZT 7, peaking at ZT 5–6. Copulations occurred between ZT 2 and ZT 8, with a higher frequency between ZT 5–7 and a peak at ZT 6. Mean duration was 0.28 ± 0.03 min/male (range: 5–163 min). Males in the leks attempted to copulate mainly between ZT 3 and ZT 7 with a peak at ZT 6, and males outside leks peaked at ZT 7. The different timing of sexual behaviors among related sympatric species, including A. zenildae, may contribute to species isolation

Male behavioral response to the urine odor of females in lesser mouse lemur (Microcebus murinus Miller, 1777)(Cheirogaleidae, Primates)

Chemical signals play an important role in Microcebus murinus Miller, 1777 social communication, a representative species of prosimians. It presents the major and vomeronasal olfactory systems and uses mainly urine for chemical marking. I studied the effect of females’ urine on the behavior of 14 males in 3 group conditions: intact, vomeronasalectomized (VNx) and bulbectomized (Bx). Stimuli presented were pro-estrus female’s urine, post-estrus female’s urine, distilled water and female’s presence. The groups were submitted to two phases: familiarization in the cage (3 days), and experimental stage (4 days) when each stimulus was presented for 30 min once a day. Results showed that intact males could discriminate different chemical stimuli; VNx males continued to discriminate stimuli using the major olfactory system but not as efficiently as intact animals; Bx animals did not perform any olfactory discrimination. The reduction in olfactory discrimination by VNx and Bx males may have been due to a central action of bulb activity

FATORES BIÓTICOS E ABIÓTICOS QUE INFLUENCIAM O DESENVOLVIMENTO DE BRANCONETA (CRUSTACEA: ANOSTRACA)

Fatores bióticos e abióticos nos viveiros de cultivo da Estação de Piscicultura da CHESF e da região de Paulo Afonso, Bahia que influenciam no desenvolvimento de Dendrocephalus brasiliensis Pesta, 1921 foram investigados mediante monitoramento realizado em quatro viveiros de cultivo, no período de dezembro de 2004 a novembro de 2005. Para os fatores bióticos e abióticos referentes à qualidade da água dos viveiros estudados, o monitoramento, foi realizado em duas épocas do ano (maio e outubro) coincidindo com os períodos chuvoso e seco, respectivamente. O manejo dos viveiros que incluiu adubação orgânica e química e complementação dos níveis de água dos viveiros fez com que as variáveis limnológicas se situassem dentro de limites toleráveis para os crustáceos em estudo possibilitando aos mesmos crescimentos em peso e comprimento e reprodução dentro de padrões normais. As águas dos viveiros pesquisados apresentaram de um modo geral condições bióticas e abióticas propícias ao desenvolvimento do microcrustáceo branconeta, D. brasiliensis