Reproductive biology of two marine catfishes (Siluriformes, Ariidae) in the Sepetiba Bay, Brazil

Marine catfish are abundant in the Sepetiba Bay, a 305 km2 area in Southeast Brazilian coast (Lat. 22 degrees 54' - 23 degrees 04' S: Long. 43 degrees 44' - 44 degrees 10' W), but the knowledge on their biology is still scanty. The reproductive biology of Sciadeichthys luniscutis (Valenciennes 1840) and Genidens genidens (Valenciennes 1839) was studied through monthly sampling, from October 1998 to September 1999. Fishes were caught with a standardized otter trawl, in the interior of Sepetiba Bay, and near to the confluence with a major freshwater contributor. Six gonadal stages were described, based on macroscopic observations of gonad form, size, weight, color and oocyte diameter, and microscopic observations of differences in size and staining in the nucleus and cytoplasm structures, as viewed through a light microscope. Changes in the gonadosomatic index (GSI) and in stages of gonadal development showed what S. luniscutis spawned in Spring, while G. genidens spawned in Summer. Total spawning was shown for both species as indicated by high concentration of post-ovulatory follicles in spent stages. Fecundity was low (14-38 vitellogenic oocytes for S. luniscutis and 6-24 for G. genidens). when compared with other teleosts. Low fecundity and separation in spawning period suggest that both species are k-strategist, able to avoid interspecific competition in early stages of life cycle to optimize the use of the available niche.     

Foraging behaviour of the Brazilian squirrelSciurus aestuans (Rodentia, Sciuridae)

We describe the foraging behaviour of the Brazilian squirrelSciurus aestuans Linnaeus, 1776 in a natural free-living population, in an area with a high concentration of palm fruitsSyagrus romanzoffiana (Chamisso) Glassman. Our objective was to investigate if the abundance ofS. romanzoffiana fruits, an important food item for squirrels, temporally influenced the foraging behaviour of this population. The observations were carried out over an eight-month (April–November 2001) period. Fruiting phenology ofS. romanzoffiana was also monitored. The most consumed food item for this period was the fruit ofS. romanzoffiana (70%), followed by foods of human origin (14%). The percentage of time spent feeding increased in September, and the time spent travelling declined in September, October and November, when females were observed showing evidence of reproductive activity. At the same timeS. romanzoffiana fruits become available. The consumption of human items illustrates the opportunistic feeding habit of these squirrels, but variations in foraging behaviour detected probably were more strongly related to availability ofS. romanzoffiana fruits.     

Occurrence and use of an estuarine habitat by giant manta ray Manta birostris

Based on the knowledge of local artisanal fishermen and on direct observations, this study presents evidence that the giant manta ray Manta birostris uses the Paranaguá estuarine complex in south Brazil, south‐western Atlantic Ocean, in a predictable seasonal pattern. Behavioural observations suggest that the estuary can act as a nursery ground for M. birostris during the summer.     

Activity and space patterns of Pyrenean desman (Galemys pyrenaicus) suggest non-aggressive and non-territorial behaviour

The Pyrenean desman is considered a flagship species for biodiversity and evolution. However, its scientific knowledge is still under development and currently on debate, particularly in relation to its behavioural ecology and social organization. Based on the previous hypothesis of individual desmans being solitary and territorial, activity and space patterns were considered to be arranged to avoid conspecifics. However, recent insights into the species’ social behaviour revealed non-interspecific avoidance. With this study, we provide novel insights into the activity and space patterns of the desman, and their relation to its social behaviour. A total of 30 individuals were trapped, 18 of which provided informative radiotracking data to study (1) activity behaviour, (2) the proportion of the home range utilized and the distances travelled, and (3) the dominant movement directionality. Activity and space use patterns were affected by daylight and seasonality, but not by sex, age or number of other conspecifics sharing the home range. In contrast to the previous observations, individuals did not show a pattern of directionality in their movements. Noticeably, we observed encounters between individuals without evidence of aggressive behaviour. Our results suggest that desmans do not alter their activity or their spatial behaviour to avoid encounters with conspecifics, as previously suggested. These novel findings provide more evidence of a social structure and organization with social interactions and non-aggressive behaviour. This is of relevance for management actions and for the conservation of this endemic mammal.     

The Relationship Between Scientific Knowledge and Behaviour: An HIV/AIDS Case

Debates on the role of scientific knowledge to affect behaviour are continuing. The theory of planned behaviour suggests that behaviour is influenced by attitudes, subjective norms and perceived behavioural control and not by knowledge. However, a large body of knowledge argues that increased HIV/AIDS-related knowledge leads to the adoption of safe behavioural practices. The purpose of this non-experimental survey study, therefore, was to investigate the correlation between academic HIV/AIDS knowledge, functional HIV/AIDS knowledge and self-reported behavioural preferences of 300 biology and 243 non-biology students from nine South African schools. Results suggest a correlation between students’ understanding of academic and functional HIV/AIDS knowledge. The behavioural preferences of both biology and non-biology students were generally the same and safe. Among biology students, correlation was observed between academic HIV/AIDS knowledge and self-reported safe behavioural preferences, which was not the case for non-biology students, where functional HIV/AIDS knowledge correlated with self-reported safe behavioural preferences. Within schools, however, no correlation was found between both forms of HIV/AIDS knowledge and self-reported safe behavioural preferences. There were indications that context-specific local factors have a greater influence on behavioural preferences. These findings suggest that the type of knowledge that could influence behaviour is informed by context-specific dynamics.     

Fishermen do more than fish: local ecological knowledge of raftsmen about the arboreal species used to construct rafts (Bahia,Brazil)

Background

Traditional raft (jangada), piúba wood raft (jangada de pau de piúba), six-log raft (jangada de seis paus), and wooden raft (jangada de pau) are some of the names given to the traditional Brazilian watercrafts created from the buoyancy of bound logs. The traditional raft is a watercraft used and built by artisan fishermen who have, throughout generations, kept and improved knowledge related to this practice and the use of the plant species they need as raw materials. Active groups of these fishermen and their watercrafts are distributed along 200?km of the coast of the state of Bahia. The fishermen interviewed in this study are at the southern limit of distribution for the use of this type of vessel.

Methods

This study aimed to characterize the use of the arboreal species applied in the construction of the traditional raft in the municipalities of Uruçuca, Ilhéus, and Canavieiras in the southern State of Bahia, Brazil. For this purpose, structured and semi-structured interviews were individually conducted with 36 fishermen, and walking tours were conducted with specialists in the construction of the watercraft.

Results

We observed that the raftsmen use 21 species to construct the traditional raft. The features of the wood, such as density, flexibility, and availability, are the main criteria applied to choose the arboreal species. Some species are preferred, such as pau de jangada (Apeiba tibourbou) and biriba (Eschweilera ovata), which are the most frequently employed in watercraft manufacturing.

Conclusions

The southern Bahia population is familiar with the different tree species that are linked to their fishing activities. The main link between the fishermen and the useful species is present in the practice of raft construction. Currently, the restricted access to raw materials limits this practice, which consequently results in the cultural erosion of this community.

     

The behaviour of sharks

Summary Despite the recent upsurge of interest in shark research, the current status of knowledge of the behavioural repertoire of most species is alarmingly incomplete. Clearly, from the steadily decreasing numbers of sharks caught by commercial and sport fishermen, sharks are highly vulnerable to human exploitation. Although education is making inroads, there is still steady opposition to the enforcement of catch limits and management strategies for most species. Accurate life history and behavioural information is required to enforce management policies. Wetherbee et al. (1990) cited a case in which commercial fishermen accused the spiny dogfish of stripping the commerical and recreational fisheries of their herring and salmon catch. A detailed study of the spiny dogfish diet disproved their claims.Sharks are clearly not mindless eating machines, as they have been labelled in the past. They are intelligent and have complex patterns of movement, space utilization, and social organization. Using a combination of remote and direct observational techniques, the scientific community is beginning to have a more complete understanding of these important apex predators in coral reef and oceanic ecosystems. More importantly, researchers who are interested in pursuing the fascinating field of shark behaviour still have a wide choice of direction.     

A review of glass eel migratory behaviour,sampling techniques and abundance estimates in estuaries: implications for assessing recruitment,local production and exploitation

Recruitment of the three northern hemisphere eel species (European eel Anguilla anguilla, American eel Anguilla rostrata and Japanese eel Anguilla japonica) has reduced significantly over the past thirty-five years. The stock of the European eel is described as being outside safe biological limits, with urgent action required by European Union Member States to assist recovery of the panmictic stock. Stock recruitment models and estimates of silver eel output from a river catchment are strongly influenced by the degree of certainty in estimating key population parameters of each life history stage. Therefore, management decisions aimed at enhancing eel populations rely on sound scientific evidence, based upon a fundamental understanding of the complex anguillid eel life cycle. This review paper focuses on the estuarine entry phase of the eel life cycle and synthesises the current scientific knowledge with regard to glass eel migratory behaviour, sampling methods and abundance estimates within estuaries. Although the behavioural and environmental processes modulating glass eel migration patterns are reasonably well understood, site specific factors play a significant role in determining fine scale distribution patterns at an individual estuary level. Given the large resource commitment required to adequately sample this key life history stage, behavioural studies of migration patterns on a local scale are crucially important to aid the design of robust sampling programmes aimed at quantifying seasonal abundance and annual recruitment.     

Behaviour-Genetics of Lake Charr (Salvelinus namaycush) and Brook Charr (S. fontinalis): Observation of Backcross and F2 Generations

Brook charr (Salvelinus fontinalis) defend territories and show high levels of agonistic behaviour. In contrast, lake charr (S. namaycush) are non-territorial and rarely show any agonistic behaviour. The genetic determinance of behavioural differences between these species was confirmed by the behavioural similarity of brook charr backcross hybrids and brook charr and a significant maternal effect on hybrid behavioural phenotypes. Backcross and F₂ generations showed either one of two distinct behavioural strategies, one aggressive and territorial and the other non-aggressive and non-territorial. It seems most likely that these strategies are conditional on individual phenotypes, such as size of nearby conspecifics. However, precise measurements of costs and benefits of each strategy are required to distinguish between these alternate hypotheses for either species. Each action pattern was an independent pattern of variation and a distinct behavioural unit. However, patterns were coordinated with all other patterns at a higher hierarchical level (corresponding to the particular behavioural strategy). It seems most likely that these strategies would be controlled by a polygenic system, even though the nature of our data does not allow us to make firm conclusions in this regard.     

5',6'-dehydroguiachrysine and 5',6'-dehydroguiaflavine, two curarizing quaternary indole alkaloids from the stem bark of Strychnos guianensis

Two new quaternary indole alkaloids 5',6'-dehydroguiachrysine (1) and 5',6'-dehydroguiaflavine (2) were isolated from Strychnos guianensis stem bark. Their structures were determined by analysis of spectral data. Their inhibitory effects on neuromuscular transmission are also reported and compared to that of other quaternary alkaloids.     

Reproductive Success Associated with Territoriality, Sneaking, and Grouping in Male Rose Bitterlings, Rhodeus ocellatus (Pisces: Cyprinidae)

The spawning success of male rose bitterlings, Rhodeus ocellatus, adopting an alternative reproductive style, was estimated through behavioural data and electrophoretic paternal analyses in field observations and experiments. Three mating patterns were observed: territoriality, sneaking, and grouping. Mating patterns depended on a male's relative size and on local male density (the number of males around a spawning spot: a mussel). Spawning patterns (pair spawning, pair spawning with sneaker, and group spawning) varied with local male density. Time-budget data of the territorial males indicated a trade-off between chasing and courtship behaviour as local male density changed. Females deposited appoximately only 1 egg per egg-laying into the mussels. As a result of isozyme analysis, a minimum of 12% (two out of 17) of the offspring in the sample were found to have been fathered by sneaker males in pair spawning with sneaker. I scored through behavioural data the mating success per spawning for each pattern, on an individual basis. The average reproductive success per spawning for each pattern was: territorial (0.61), sneaking (0.31) and grouping (0.11), and thus the successes of the patterns were not equal. Accordingly, the alternative reproductive styles of male rose bitterlings are best interpreted as alternative phenotypes in a conditional behaviour.     

Movement Activity Based Classification of Animal Behaviour with an Application to Data from Cheetah (Acinonyx jubatus)

We propose a new method, based on machine learning techniques, for the analysis of a combination of continuous data from dataloggers and a sampling of contemporaneous behaviour observations. This data combination provides an opportunity for biologists to study behaviour at a previously unknown level of detail and accuracy; however, continuously recorded data are of little use unless the resulting large volumes of raw data can be reliably translated into actual behaviour. We address this problem by applying a Support Vector Machine and a Hidden-Markov Model that allows us to classify an animal''s behaviour using a small set of field observations to calibrate continuously recorded activity data. Such classified data can be applied quantitatively to the behaviour of animals over extended periods and at times during which observation is difficult or impossible. We demonstrate the usefulness of the method by applying it to data from six cheetah (Acinonyx jubatus) in the Okavango Delta, Botswana. Cumulative activity data scores were recorded every five minutes by accelerometers embedded in GPS radio-collars for around one year on average. Direct behaviour sampling of each of the six cheetah were collected in the field for comparatively short periods. Using this approach we are able to classify each five minute activity score into a set of three key behaviour (feeding, mobile and stationary), creating a continuous behavioural sequence for the entire period for which the collars were deployed. Evaluation of our classifier with cross-validation shows the accuracy to be , but that the accuracy for individual classes is reduced with decreasing sample size of direct observations. We demonstrate how these processed data can be used to study behaviour identifying seasonal and gender differences in daily activity and feeding times. Results given here are unlike any that could be obtained using traditional approaches in both accuracy and detail.     

The paraty artisanal fishery (southeastern Brazilian coast): ethnoecology and management of a social-ecological system (SES)

ABSTRACT: This study intends to give recommendations to the management of Paraty fishery in Brazil through an interplay of local and scientific knowledge. In particular, the objectives are the following: 1) to describe the Paraty fishery; 2) to compare the fishermen's local ecological knowledge with recorded fish landings and previous studies in Paraty; 3) to combine the data on local fishing and on local/Caicara livelihoods with the SES (social-ecological systems) Model. The methods include a systematic survey of fishing in Tarituba and Praia Grande, which are located in the northern end and the central part of the Paraty municipality, respectively. For four days each month, systematic data on catches at landing points were collected, as well as macroscopic gonad analysis data for the fishes Centropomus parallelus and C. undecimalis (snook, robalo), Epinephelus marginatus (grouper, garoupa), Scomberomorus cavalla (King mackerel, cavala), and Lutjanus synagris (Lane snapper, vermelho). Spring and summer are important seasons during which some species reproduce, and the integration of fishing periods for some target species could assist in fishing management through the use of closed seasons. Fishermen could obtain complementary earnings from tourism and from the "defeso system" (closed season including a salary payment) to conserve fishing stocks. The SES model facilitates an understanding of the historical context of fishing, its economic importance for local livelihoods, the constraints from conservation measures that affect fishermen, and the management processes that already exist, such as the defeso. If used to integrate fishing with complementary activities (tourism), such a system could improve the responsibility of fishermen regarding the conservation of fish stocks.     

An information-theory analysis of task specialization among worker honey bees performing hive duties

Worker honey bees (Apis mellifera) performing field duties are known to possess individual task specializations. However, little evidence has been forthcoming about individual specializations among the younger pre-foraging worker bees performing hive duties. This paper reports results obtained from behavioural observations of worker bees in seven hives. An information-theory analysis of these data reveals that the divergence from independence (D₂) of worker bee identity and behavioural pattern performed has a low value in all of the experimental hives. Young worker bees performing hive duties therefore do not possess detectable individual specializations. Environmental and life-history considerations that may account for this difference in behaviour between field and hive worker bees are discussed.     

In search of traditional bio-ecological knowledge useful for fisheries co-management: the case of jaraquis <Emphasis Type="Italic">Semaprochilodus</Emphasis> spp. (Characiformes,Prochilodontidae) in Central Amazon,Brazil

The jaraquis (Semaprochilodus spp.) are the most abundant group in the fishing landing in Manaus. However, just command and control management strategies have been used by the fishery governmental agency in the region without the power to enforce centralized decisions. The fishermen and their culture represent a source of information on dynamics of the resources and aquatic environments, fundamental in making possible the co-management of the fishing resources. The present study aims to contribute to management through identification of common information available in scientific and traditional knowledge about the jaraquis' bio-ecology. There were 57 semi-structured interviews recorded with fishermen of Manaus and rural areas of Manacapuru in 2002 concerning biological and ecological aspects. Similarity was observed between scientific and traditional knowledge in the following items: size of first sexual maturation, spawning type, parental care, trophic relationships and migratory behavior, as well as in some aspects of the mortality and growth of the species. However, there was less ethnoicthyological information on fecundity and the determination of the age and growth of adult fish. Common information would be used preferably by agencies to start an effective and technical dialogue with commercial and riverine fishermen to design management plans in a decentralized strategy.     

A Comparative Study of Social Behaviour of Two Sympatric Ground Squirrels (Spermophilus spilosoma,S. mexicanus)

During the reproductive period, intraspecific dyadic encounters were staged within and between S. spilosoma and S. mexicanus individuals under controlled conditions. Video recordings were used to describe and quantify behaviour of males and females of these two sympatric ground squirrels. To compare dyads within and between species two indices (an Agonistic index and a Tolerance index) were designed from measures of behavioural frequencies. During intrasexual encounters, S. mexicanns males and females appear to be more aggressive than male and female S. spilosoma. In both species, encounters between males were more aggressive than between females, which were very tolerant to each other in S. spilosoma. In most cases encounters between male and female conspecifics exhibit an intermediate level of agonistic behaviour and tolerance. The null hypothesis of similarity of the social behaviour of S. spilosoma and S. mexicanus is falsified. Some alternative hypotheses are proposed. First, the tolerance of S. spilosoma is an adaptation to the difficult environmental conditions. Thus differences between the two species reflect differences in behavioural evolution in allopatric populations. Second, S. spilosoma tolerance is a behavioural response to S. mexicanus' recent arrival.     

A declaration of intent in the kittiwake gull (Rissa tridactyla)

During the breeding seasons 1979–1982 observations were made of the vocal behaviour of the kittiwake gull (Rissa tridactyla). Attention was directed at the vocal behaviour emitted immediately preceding a bird's departure from the nest and partner. The data indicate that the kittiwake consistently makes only one type of vocalization (the Pre-departure Call) prior to departure and that the behaviour communicates intention to leave nest and partner. An analysis of the behavioural interactions reveals that the Pre-departure Call given by one bird elicits five different categories of response in the other. The data reveal that consequent partner behaviour either sanctioned or prevented absence. The functional significance of the results is discussed.     

Social and cultural efficacies of medicines: Complications for antiretroviral therapy

Ethnoecological knowledge may be understood as spontaneous knowledge, culturally referenced of any society's members, learned and transmitted through social interactions and that are targeted at resolution of daily routine situations. The traditional knowledge in small scale economy societies as well as the non-academic knowledge in urban-industrial societies might be included in this concept. An ethnoecological approach study was performed here on people living at the communities of Alvinho, Almeida, Chã do Marinho, Floriano, and Chã de Oiti, all located in the municipality of Lagoa Seca, Paraíba state, Northeast Brazil. The general objective pursued here was to study the knowledge that peasant farmers have on management of plant species utilized for pest control. For this, the methodological instruments employed here to investigate the ethnoecological knowledge were: direct observation, structured and semi-structured interviews, and tours conducted by local peasant farmers. We analyzed the data obtained under an emic/etic view and also by comparing the local knowledge with those obtained from the literature. The results showed that people in those communities utilize management alternatives for controlling pests, which are mainly: (i) fallowing; (ii) crop rotation; (iii) destruction of crop remains and fruits attacked by pests; (iv) alternations of crops with repellent plants; and/or (v) mixed cropping; (vi) insect's larvae covered with soil; (vii) crops irrigated abundantly; and (viii) soil preparation. The recovery and comprehension we get about this knowledge as well as the farmers' savoir faire, are extremely important to the revival of ancient agricultural practices, which have been forgotten due to advances in modern agriculture. The data obtained here showed that a huge body of knowledge the farmers have on many forms or strategies of management are generally compatible with scientific knowledge.