Population attributes of Littoraria angulifera (Gastropoda: Littorinidae) in mangroves in Bahia State, northeastern Brazil

Littoraria angulifera (Lamarck, 1822) is an estuarine gastropod of tropical occurrence, which lives mainly on trunks of mangrove tree species. This study aimed to evaluate the population attributes of this species, such as abundance, space-time distribution, sex ratio and recruitment in mangroves in Bahia State, northeastern Brazil. The specimens were collected monthly throughout 2018, on trunks of the red mangrove Rhizophora mangle L. at two heights and on two horizontal levels. Specimens that were on the marine grass Spartina alterniflora Loisel were also collected. After counting, biometrics and sexing, the specimens were returned alive to the environment. The average size and weight of L. angulifera was higher (p<0.05) in places with taller and less sparse trees and the vertical distribution on the trunks showed a preference for strata close to the soil. Both results are related to shading and protection against desiccation. Females were more abundant than males, at an approximate sex ratio F: M of 1.4: 1. Recruits were observed throughout the period, showing continuous reproduction of the species with a recruitment peak in spring (September to November). The study revealed the importance of keep the mangroves intact to allow the maintenance of the natural stocks of the species.

SOCIO-CULTURAL VIEWS OF PERSONAL ECOLOGICAL CULTURE

The article discusses the socio-cultural aspects of the formation of a person's ecological culture. It is well-founded that the important criterion for the ecologicalization of the socio-cultural environment is the formation of the ecological culture of the individual and the society. The socio-cultural environment encompasses all spheres of human life, ensuring the continuous reproduction of the "education-culture-society" quarter - vitality according to the laws of nature.

Age and growth of the shark, Mustelus higmani (Carcharhiniformes: Triakidae) from Venezuela

Introduction: Mustelus higmani is one of the shark species most commonly caught in the northeastern region of Venezuela; however, this species has been poorly studied. Objective: to evaluate the age and growth of M. higmani on the basis of the optical analysis of vertebrae. Methods: Between August 2016 and July 2017, the vertebral samples were collected in the fishing port of Juan Griego, Margarita Island. The growth study was based on a sample of 238 individuals, 86 males (24.1-59.5 cm TL) and 152 females (24.4-69.5 cm TL) and the use of growth modeling approaches. Results: The RMI analysis indicated an annual periodicity for the deposition of growth rings. Ages assigned varied between 0 and 5 years in males, and between 0 and 6 years in females. The estimates of growth parameters obtained were L∞ = 60.8 cm TL, k = 0.54 years-1 and t0 = -1.04 years in males; and L∞ = 72.4 cm TL, k = 0.40 years-1 and t0 = -1.31 years in females. The ages at maturity and longevities resulted respectively in 2.5 and 6.4 years for males; and in 2.0 and 8.7 years for females. Conclusions: In general, results indicate that M. higmani has a rapid growth, early maturity, short longevity, and continuous reproduction, characterizing it as a biologically productive species. Key words: Caribbean; ecology; elasmobranchs; fishery; sharks.

ON TECHNIQUE OF CULTIVATION OF MARINE AND BRACKISH-WATER CILIATES

The paper shows the results of the study of cultivating marine and brackishwater ciliates conducted at the experimental centre “Zavetnoe” (the Kerch Strait) in 2008-2019. The main parameters for the ciliates cultivation have been defined and the effectiveness of nutrient mixtures for their feeding have been analyzed. Planktonic ciliates Euplotes affinis Dujardin, 1842; Euplotes charon O. F. Müller, 1786; Mesodinium pulex Claparede et Lachmann, 1858 were taken as the research material. Growing was carried out under the tent and in the open air, in ambient conditions, in cultivation containers in broad daylight and with artificial lighting at night. Coral-shell fractions in 5-7 kg/m2 were put on the bottom of the pools as the underlying layer. The density of seeding the uterine culture in E. affinis was 5-10 ind./ml, in E. charon and M. pulex - 1-2 ind./ml. Cultivation of ciliates was carried out in spring and autumn. According to the results of the study, the feed is better used in the form of water-soluble nutrient mixtures. Due to the fact that the nutrient ingredients are in a dissolved state, they are absorbed faster by organisms. This leads to the continuous reproduction of the culture of populations, which helps to grow ciliates even at suboptimal temperatures. Nutrient mixtures are recommended to be added to the culture containers 15-20 days before the introduction of the uterine culture. It has been stated that the increased density of ciliates occurs regardless of the composition of the feed; the density of ciliates always depends on the composition of the nutrient mixture. The best results are obtained when using a nutritious mixture with horse manure and dry banana skin.

ACOUSTICS OF PROCESS AS A FACTOR OF FORMING IN THE COMBUSTION ZONE OF FORMATIONS WITH EXCESS CHARGE

The nature and mechanism of formation and reproduction in time of macroscopic, fluctuational nature of formations with uncompensated electric charge (aquazineutral or AQN-formations) fixed by observations in the burning zone are investigated. With account of characteristic to combustion acoustic manifestations it is shown, that when burning in the reacting medium are necessarily developed instabilities in the distribution of electrical charge over the volume.It is substantiated, that the excitation conditions and the general features of charge instabilities in distribution of charge over volume really determine the mechanism under study as factor jointly providing of both the formation and continuous reproduction of AQN-formations in the combustion zone (in the pre-flame region, first of all).

Population structure of Macrobrachium amazonicum (Heller, 1862) (Decapoda: Palaemonidae) in Miranda Hydroelectric Plant Reservoir, Araguari river, Minas Gerais, Brazil

Aim The present study aimed to analyze a M. amazonicum population structure in a reservoir of the “Triângulo Mineiro”, Brazil. Methods Monthly surveys were carried out from April/2012 to May/2013 at the Miranda Hydroelectric Plant Reservoir located in Araguari river, state of Minas Gerais. A sampling section of 100 m long, 5 m wide and depth not exceeding 1 m was defined on the banks of the reservoir. Sampling consisted on two persons quickly passing a 2 mm sieves in partially submerged marginal vegetation, for one hour. The sampled specimens were identified, sexed and measured. Results A total of 2,584 specimens were analyzed, of which 64.62% were females (3.93% ovigerous, 5.94% non-ovigerous and 54.75% juveniles), 29.16% males (21.41% adults and 7.76% juveniles) and 6.22% juveniles of undetermined sex. The sex ratio (1:2.21) indicated a clear deviation for females, for the whole sampling period, monthly and for each size class. Males had an average carapace length (CL = 4.50 ± 0.71 mm) significantly lower than females (CL = 4.64 ± 1.47 mm) and the size frequency distribution revealed a unimodal pattern, with peaks occurring in 4.0 - 4.9 mm size class for males and in 3.0 - 3.9 mm size class for females. The relation between total and carapace length was significant, indicating a negative allometric growth. No males’ morphotypes were found. The population presented a continuous reproduction with a gradual increase between April and June/2012. Female sexual maturity was determined for 6.3 mm of CL, while for males was estimated for 4.0 mm. Conclusion The Miranda reservoir population had a body size variation similar to the continental populations of Pantanal. The sexual dimorphism observed may be related to the absence of male morphotypes and to the “pure search” reproduction strategy. The deviated sex ratio for females may increase the chance of fertilization and the reproductive success. The presence of juveniles and ovigerous females throughout the year indicates a continuous reproduction pattern of the population.

COMPORTAMENTO FENOLÓGICO DE Emmotum nitens (Benth.) Miers (METTENIUSACEAE) EM FRAGMENTO DE CERRADÃO

Emmotum nitens é uma espécie bem conhecida em termos de florística e fitossociologia, entretanto, há poucos trabalhos que tratam-se de sua fenologia. Este estudo buscou avaliar a fenologia reprodutiva de uma população de E. nitens no Município de Rio Verde, Goiás. Observou-se mensalmente as fenofases reprodutivas (botão, antese, fruto imaturo e maduro) de 15 indivíduos. Para a coleta dos dados utilizou-se o método de Fournier e presença/ausência, e para analisar os mesmos utilizou-se a estatística circular e correlação com as variáveis meteorológicas (temperatura e precipitação). E. nitens produziu botões e flores de modo irregular ao longo do estudo, no entanto se correlacionaram positivamente com a temperatura. Durante todo estudo registrou-se frutos imaturos, embora as maiores concentrações ocorreram na transição do período seco-chuvoso e durante as chuvas, correlacionando-se positivamente com a precipitação. A maturação dos frutos iniciou-se no final da estação das chuvas, com maiores intensidades no período seco. Para E. nitens é mais vantajoso apresentar reprodução continua já que a mesma não é fortemente limitada pelas variáveis climáticas da área de estudo, do que seguir um padrão sazonal.Palavra-chave: fenologia, espécie de cerrado, eventos reprodutivos, correlação com metereologia. PHENOLOGICAL BEHAVIOR OF EMMOTUM NITENS (BENTH.) MIERS (METTENIUSACEAE) ON CERRADÃO FRAGMENT ABSTRACT:Emmotum nitens is a well-known species in terms of floristic and phytosociology, however, there are few studies that deal with its phenology. The objective of this study was to evaluate the reproductive phenology of a population of E. nitens in the municipality of Rio Verde, Goiás. The reproductive phenomena (flower bud, anthesis, immature fruit and ripe fruit) were observed monthly in 15 individuals. Fournier method and presence/absence were used to collect the data, and to analyze them, the circular statistic and correlation with the meteorological variables (temperature and precipitation) were used. E. nitens produced flower bud and flowers irregularly throughout the study, however they correlated positively with temperature. During the whole study immature fruits were recorded, although the highest concentrations occurred in the transition from the dry-rainy season and during the rains, correlating positively with the precipitation. Fruit maturation began at the end of the rainy season, with higher intensities in the dry season. For E. nitens it is more advantageous to present continuous reproduction since it is not strongly limited by the climatic variables of the study area, rather than following a seasonal pattern.Keywords: phenology, species of cerrado, reproductive events, correlation with meteorology. DOI: