Histological aspects of the mucosa of the spermaceti chamber of a dwarf sperm whale / Aspectos histológicos da mucosa da câmera do espermacete de cachalote-anão

The sound producing apparatus of the dwarf sperm whale (Kogia sima) presents a complex anatomic structure composed of melon, spermaceti, phonic lips, vocal cap, case, papillae, spermaceti chamber and other airspaces, as well as facial muscles involved in sound production. The spermaceti chamber rests on the caudal portion of the premaxilla, with part of its mucosa covered with spherical/oval-shaped structures (approximately 1 to 2 mm in diameter), compatible with vesicles (previously referred to as "papillae"). Macroscopical examination revealed whitish, firm, widely and irregularly distributed vesicular mucosa on the premaxillary portion of the spermaceti chamber of a K. sima specimen stranded on the coast of Santos (southeastern Brazilian coast). Upon microscopic examination, walls of connective tissue with abundant type I collagen forming vesicles with an internal space or cavity filled with a small amount of eosinophilic substance compatible with mucoproteic fluid were observed. The base of such vesicles presented glands within the connective tissue, probably responsible for fluid production. This study describes the histology of the mucosa of the spermaceti chamber of a K. sima specimen and characterizes the glands associated with fluid production.(AU)

O sistema de produção sonora do cachalote-anão (Kogia sima) apresenta uma complexa estrutura anatômica composta por melão, espermacete, lábios fônicos, "vocal cap", "case", papilas, câmara do espermacete e outros espaços aéreos, além de músculos faciais envolvidos na produção sonora. A câmara do espermacete localiza-se na porção caudal da pré-maxila, apresentando parte de sua mucosa recoberta por estruturas esférico-ovaladas de aproximadamente 1 a 2 mm de diâmetro, compatíveis com vesículas (previamente denominadas "papilas"). Ao exame macroscópico de um espécime de K. sima encalhado no litoral de Santos (sudeste da costa brasileira), foi identificada mucosa esbranquiçada e firme ao corte, ampla e irregularmente distribuída na porção pré-maxilar da câmara do espermacete. Ao exame microscópico foram observadas vesículas compostas por abundante tecido conectivo de colágeno tipo I, dando origem a um espaço interno ou cavidade, contendo pequena quantidade de substância eosinófila, compatível com fluido mucoprotêico. Estruturas glandulares foram observadas em tecido conjuntivo na base das vesículas, provavelmente responsáveis pela produção do fluido observado no interior das mesmas. Esse estudo caracteriza histologicamente a mucosa da câmara do espermacete de um espécime de K. sima e as glândulas relacionadas a sua produção secretória.(AU)

¿Pueden los perros domésticos (canis lupus familiaris) reconocer expresiones emocionales humanas? una revisión crítica de las evidencias / Can domestic dogs (canis lupus familiaris) recognize human emotional expressions? a critical review of the evidence

Las expresiones emocionales tienen un papel fundamental en las interacciones de especies sociales, brindando información acerca del emisor, las características e importancia del estímulo o situación que desencadena tales interacciones, y también funcionan regulando los vínculos sociales. Los perros poseen notorias capacidades comunicativas hacia los humanos por lo que resulta interesante estudiar si estas habilidades se extienden al reconocimiento de las expresiones emocionales. Se han realizado diversas investigaciones acerca del reconocimiento de expresiones emocionales humanas en perros exponiéndolos a una situación representada por personas durante la evaluación, así como mediante el uso de imágenes, videos y grabaciones. El análisis de las evidencias permite concluir que los perros podrían distinguir entre distintas emociones humanas ya sea en presencia de modelos en vivo o mediante la observación de imágenes y modulan su conducta conforme esta discriminación, así como también pueden utilizar esta información como clave en la resolución de problemas. Sin embargo, aún no están claros los mecanismos que subyacen a estas habilidades.

Emotional expressions play a critical role in the interactions among individuals, particularly, in social species. They provide information about the sender and the characteristics and importance of the triggering stimulus or situation, also regulating social ties. Dogs have notorious communication skills towards humans, which makes the study of their ability to recognize human emotional expressions an interesting endeavor. There have been several studies in which dogs have been tested using real people in an experimental situation as well as images, video and audio recordings of people's expressions. The evidence suggests that dogs can discriminate between different human emotions either in the presence of live models or by looking at images. This type of information has been shown to modulate their behavior and to be used as cues to solve problems. However, the mechanisms underlying these abilities are not fully understood yet.

Acoustic communication in insect disease vectors

Acoustic signalling has been extensively studied in insect species, which has led to a better understanding of sexual communication, sexual selection and modes of speciation. The significance of acoustic signals for a blood-sucking insect was first reported in the XIX century by Christopher Johnston, studying the hearing organs of mosquitoes, but has received relatively little attention in other disease vectors until recently. Acoustic signals are often associated with mating behaviour and sexual selection and changes in signalling can lead to rapid evolutionary divergence and may ultimately contribute to the process of speciation. Songs can also have implications for the success of novel methods of disease control such as determining the mating competitiveness of modified insects used for mass-release control programs. Species-specific sound “signatures” may help identify incipient species within species complexes that may be of epidemiological significance, e.g. of higher vectorial capacity, thereby enabling the application of more focussed control measures to optimise the reduction of pathogen transmission. Although the study of acoustic communication in insect vectors has been relatively limited, this review of research demonstrates their value as models for understanding both the functional and evolutionary significance of acoustic communication in insects.

Ultrasound call detection in capybara / Detecção de chamados de ultrassom em capivara

The vocal repertoire of some animal species has been considered a non-invasive tool to predict distress reactivity. In rats ultrasound emissions were reported as distress indicator. Capybaras[ vocal repertoire was reported recently and seems to have ultrasound calls, but this has not yet been confirmed. Thus, in order to check if a poor state of welfare was linked to ultrasound calls in the capybara vocal repertoire, the aim of this study was to track the presence of ultrasound emissions in 11 animals under three conditions: 1) unrestrained; 2) intermediately restrained, and 3) highly restrained. The ultrasound track identified frequencies in the range of 31.8±3.5 kHz in adults and 33.2±8.5 kHz in juveniles. These ultrasound frequencies occurred only when animals were highly restrained, physically restrained or injured during handling. We concluded that these calls with ultrasound components are related to pain and restraint because they did not occur when animals were free of restraint. Thus we suggest that this vocalization may be used as an additional tool to assess capybaras[ welfare.

O repertório vocal de algumas espécies de animais tem sido considerado uma ferramenta não invasiva para predizer o distresse. Em ratos, emissões de ultrassom foram registradas como indicador de distresse. O repertório vocal de capivaras foi relatado recentemente e parece haver a presença de chamados em ultrassom que ainda não foram confirmados. Assim para associar o estado de bem-estar empobrecido em capivaras e a possibilidade de ocorrência de ultrassom em seu repertório vocal, o presente estudo teve como objetivo rastrear a presença deste tipo de vocalização em 11 animais submetidos a três condições diferentes: 1) sem contenção; 2) média contenção e 3) alta contenção. O rastreamento revelou a presença de faixas de frequência de 31,8±3,5 kHz em adultos e 33,2±8,5 kHz em filhotes. Estas emissões encontradas na faixa de ultrassom ocorreram apenas durante a alta contenção, quando contidos fisicamente ou feridos durante o manejo. Concluímos que tais emissões, com componentes de ultrassom, estão relacionadas à dor e ao distresse de contenção pois não ocorreram quando os animais estavam livres de contenção. Assim sugerimos que esta vocalização pode ser usada como uma ferramenta adicional para acessar o estado de bem-estar em capivaras.

Spatial choice is biased by chemical cues from conspecifics in the speckeled worm eel Myrophis punctatus

The speckeld worm eel Myrophis punctatus lives in high-densities assemblages, and usually digs through, or lies on the substrate. These behaviours could lead to chemical marks on the substrate and could modulate the spatial distribution in this species. We tested the hypothesis that the spatial choice of the speckled worm eel is modulated by the presence of conspecific odour on the substrate. Here, we showed that the speckled worm eel avoids the substrate area containing the conspecific odour, indicating that this chemical cue modulates the eel's spatial decision. The eels clearly detected the conspecific's odour. This perception might indicate the presence of conspecifics into the substrate. Since the eels avoided an area containing conspecific odour, we suggest this may be a response that avoids the consequences of invading a resident-animal's territory.

A enguia mirongo-mirim Myrophis punctatus vive em agrupamentos de alta densidade populacional e comumente se enterra ou permanece sob o substrato. Esses comportamentos podem levar a marcas químicas no subtrato e podem, portanto, modular o uso do espaço nessa espécie. Neste estudo, testamos a hipótese de que a preferência espacial da enguia mirongo-mirim é influenciada pela presença de odor do animal coespecífico no subtrato. Mostramos que as enguias evitam a área que contém tal odor, indicando que as decisões de ocupação espacial podem ser influenciadas por pistas químicas de coespecíficos. As enguias claramente detectaram o odor de um animal coespecífico e essa percepção poderia ser um indicativo da presença de um coespecífico enterrado no substrato. Visto que elas evitam uma área contendo tal odor, sugerimos que isso poderia ser uma resposta para evitar invadir o território de um animal residente.

Exploiting triatomine behaviour: alternative perspectives for their control

Living in close association with a vertebrate host and feeding on its blood requires different types of adaptations, including behavioural adjustements. Triatomines exhibit particular traits associated with the exploitation of their habitat and food sources and these traits have been the subject of intense analysis. Many aspects of triatomine behaviour have been relatively well characterised and some attempts to exploit the behaviours have been undertaken. Baited traps based on host-associated cues, artificial refuges and light-traps are some of the tools used. Here we discuss how our knowledge of the biology of Chagas disease vectors may help us sample and detect these insects and even increase the efficiency of control measures.

Visual communication stimulates reproduction in Nile tilapia, Oreochromis niloticus (L. )

Reproductive fish behavior is affected by male-female interactions that stimulate physiological responses such as hormonal release and gonad development. During male-female interactions, visual and chemical communication can modulate fish reproduction. The aim of the present study was to test the effect of visual and chemical male-female interaction on the gonad development and reproductive behavior of the cichlid fish Nile tilapia, Oreochromis niloticus (L.). Fifty-six pairs were studied after being maintained for 5 days under one of the four conditions (N = 14 for each condition): 1) visual contact (V); 2) chemical contact (Ch); 3) chemical and visual contact (Ch+V); 4) no sensory contact (Iso) - males and females isolated. We compared the reproductive behavior (nesting, courtship and spawning) and gonadosomatic index (GSI) of pairs of fish under all four conditions. Visual communication enhanced the frequency of courtship in males (mean ± SEM; V: 24.79 ± 3.30, Ch+V: 20.74 ± 3.09, Ch: 0.1 ± 0.07, Iso: 4.68 ± 1.26 events/30 min; P < 0.05, two-way ANOVA with LSD post hoc test), induced spawning in females (3 spawning in V and also 3 in Ch+V condition), and increased GSI in males (mean ± SEM; V: 1.39 ± 0.08, Ch+V: 1.21 ± 0.08, Ch: 1.04 ± 0.07, Iso: 0.82 ± 0.07 percent; P < 0.05, two-way ANOVA with LSD post hoc test). Chemical communication did not affect the reproductive behavior of pairs nor did it enhance the effects of visual contact. Therefore, male-female visual communication is an effective cue, which stimulates reproduction among pairs of Nile tilapia.

Genetic divergence between two sympatric species of the Lutzomyia longipalpis complex in the paralytic gene, a locus associated with insecticide resistance and lovesong production

The sandfly Lutzomyia longipalpis s.l. is the main vector of American Visceral Leishmaniasis. L. longipalpis s.l. is a species complex but until recently the existence of cryptic sibling species among Brazilian populations was a controversial issue. A fragment of paralytic (para), a voltage dependent sodium channel gene associated with insecticide resistance and courtship song production in Drosophila, was isolated and used as a molecular marker to study the divergence between two sympatric siblings of the L. longipalpis complex from Sobral, Brazil. The results revealed para as the first single locus DNA marker presenting fixed differences between the two species in this locality. In addition, two low frequency amino-acid changes in an otherwise very conserved region of the channel were observed, raising the possibility that it might be associated with incipient resistance in this vector. To the best of our knowledge, the present study represents the first population genetics analysis of insecticide resistance genes in this important leishmaniasis vector.

Singing of Neoconocephalus robustus as an example of deterministic chaos in insects.

We use nonlinear time series analysis methods to analyse the dynamics of the sound-producing apparatus of the katydid Neoconocephalus robustus. We capture the dynamics by analysing a recording of the singing activity. First, we reconstruct the phase space from the sound recording and test it against determinism and stationarity. After confirming determinism and stationarity, we show that the maximal Lyapunov exponent of the series is positive, which is a strong indicator for the chaotic behaviour of the system. We discuss that methods of nonlinear time series analysis can yield instructive insights and foster the understanding of acoustic communication among insects.

Chemical modulation on heterogeneous growth in Prochilodus lineatus (Valenciennes, 1847) (Pisces; Characiformes)

In the present study, the effect of chemical factors released by conspecifics on growth variability (heterogeneous growth - HetG) in a gregarious fish species (Prochilodus lineatus) was tested. HetG was assessed by the weight variation coefficient in two consecutive 21-day periods. The fish were grouped in tanks (4 fish in each) that received running water with constant draining. The tanks contained either conspecifics (C) or non-conspecifics (N). Four conditions were established in accordance with the tank water supply: a) water with previous contact with conspecifics throughout the experiment (CC); b) water without previous contact with conspecifics throughout the experiment (NN); c) water with previous contact with conspecifics in just the first period, 0 to 21 days (CN); and d) just in the period from 21 to 42 days (NC). At the end of the experiments, the occurrence of chemical modulation on the growth variability in P. lineatus was verified: the fish that received water with previous contact with a conspecific (C) presented exacerbation of HetG. This corroborates the notion that the predominant mechanism in the determination of intraspecific growth variation in the gregarious species is associated to chemical factors released by conspecifics.

No presente trabalho, testou-se o efeito de fatores químicos liberados por coespecíficos sobre o crescimento e sua variabilidade no grupo (crescimento heterogêneo, CHet), numa espécie gregária, o curimbatá, Prochilodus lineatus. O CHet foi avaliado pelo coeficiente de variação do peso dos animais, em dois períodos consecutivos de 21 dias. Os peixes foram agrupados em aquários (4 peixes cada) que receberam água corrente, com vazão constante, de tanques contendo (C) ou não (N) coespecíficos. Quatro condições foram delineadas de acordo com a água que abastecia os aquários: a) água com contato prévio com coespecíficos durante todo o experimento (CC); b) água sem contato prévio com coespecíficos durante todo o experimento (NN); c) água com contato prévio com coespecíficos apenas no primeiro período, 0 a 21 dias (CN); e d) apenas no período de 21 a 42 dias (NC). Ao término dos experimentos, verificou-se que ocorre modulação química sobre a variabilidade de crescimento em P. lineatus: os peixes que receberam água com contato prévio com coespecífico (C) apresentaram exacerbação do CHet. Fato que corrobora a idéia de que o mecanismo predominante da determinação da variação intra-específica do crescimento, em espécies gregárias, está associado à ação de fatores químicos liberados por coespecíficos.

Colony membership is reflected by variations in cuticular hydrocarbon profile in a Neotropical paper wasp, Polistes satan (Hymenoptera, Vespidae)

Nestmate recognition is one the most important features in social insect colonies. Although epicuticular lipids or cuticular hydrocarbons have both structural and defensive functions in insects, they also seem to be involved in several aspects of communication in wasps, bees and ants. We analyzed and described for the first time the cuticular hydrocarbons of a Neotropical paper wasp, Polistes satan, and found that variation in hydrocarbon profile was sufficiently strong to discriminate individuals according to their colony membership. Therefore, it seems that small differences in the proportion of these compounds can be detected and used as a chemical-based cue by nestmates to detect invaders and avoid usurpation.

Evidence for presence of female produced pheromone components in male scent brush extract of castor semi-looper moth Achaea janata L.

Hexane extract of male terminalia (along with scent brushes) of castor semi-looper moth, Achaea janata L, elicited significant olfactory responses in both male and female insects by electroantennogram recording technique. However, male extract in the wind tunnel evoked noticeable behaviour responses in the female insects only. Orientation response of the males to the male extract was not evident in wind tunnel experiments. Two electrophysiologically-active compounds were identified from the male extract. Based on GC retention times and mass spectrometry the two compounds were confirmed as (Z,Z)-9,12-octadecadienal and (Z,Z,Z)-3,6,9-heneicosatriene. These two compounds are also constituents of female produced four-component blend of A. janata.

Electroantennography in the study of two stingless bee species (Hymenoptera: meliponini)

Relatam-se aqui os resultados preliminares de estudos eletroantenográficos realizados com duas espécies de Frieseomellita brasileira. Os experimentos com F. silvestrii e F. varia mostraram que as antenas respondem aos extratos obtidos com hexano das cabeças e dos abdômens das duas espécies e da tíbia posterior de F. silvestrii (que transporta resinas coletadas de plantas). Respondem também aos compostos puros, 2-heptanol e 2-nonanol, e aos terpenos, a-cubebeno, humuleno e b-cariofileno, encontrados nas tíbias e no cerume de seus próprios ninhos.

Identification of glandular (preputial and clitoral) proteins in house rat (Rattus rattus) involved in pheromonal communication.

Proteins (18-20 kDa) belonging to lipocalin family have been reported to act as carriers for ligands binding to pheromones in mouse urine, pig saliva, hamster vaginal fluid and human sweat, that are involved in pheromonal communication. As the preputial gland is a major pheromonal source, the present study was aimed to detect the specific protein bands (around 18-20 kDa) in the preputial and clitoral glands of the house rat, R. rattus. The amount of protein was higher in preputial gland of the male than that of female (clitoral) gland. A 20 kDa protein was noted in male and female glands; however, the intensity of the band was much higher in male than in female. In addition, 70, 60, 35 kDa bands, identified in male preputial gland, were absent in females. The presence of higher concentration of glandular proteins in the male preputial gland suggests that male rats may depend more on these glandular proteins for the maintenance of reproductive and dominance behaviours. The results further suggest that these glandular proteins (20 kDa) may act as a carrier for ligand binding.

Penguins and their noisy world

Os pingüins identificam seu parceiro ou seu filhote através de um sinal acústico, o grito de exibição. Esta identificação está realizada num ambiente particularmente exigente: o mundo barulhento de uma colônia de milhares de aves. Para entender totalmente como essas aves resolvem este problema de comunicação, realizamos observaçäes, análises acústicas e experiências de propagação e de "play-back" com 6 espécies de pingüins estudados no campo. Segundo nossos resultados, parece que os pingüins usam um sistema de codificação "anti-confusão" e "anti-barulho" particularmente eficiente, permitindo uma rápida identificação e localização dos indivíduos em movimento numa multidão barulhenta.

Urinary proteins and pheromonal communication in mammals.

Urinary proteins play a significant role as pheromones and pheromone-binders in mammalian reproduction and social behaviour. The present study was carried out to quantify the urinary proteins in five different mammalian species viz mouse, rat, rabbit, bovine and human. The results revealed that the male rodents excrete large amounts of urinary protein as compared to that of other mammals. In addition, the male mammals excrete a higher quantity of protein than do the females., suggesting the role of androgens in excretion of protein. The presence of higher concentration of urinary proteins in rodents suggests that the rodents depend more on urinary proteins for olfactory/social communication.

Aggregation Behaviour and Interspecific Responses in Rhodnius prolixus Stal

The response to intra- and interspecific faecal assembling signals was tested in Rhodnius prolixus. Papers impregnated with excrement of R. prolixus induced the aggregation of larvae of this species, but also of those of Triatoma infestans. However, faeces belonging to T. infestans were not able to assemble larvae of R. prolixus. On the other hand, there was no response of R. prolixus to putative chemical factors from their cuticle (footprints), in contrast to T. infestans. Results are discussed as related to the ecology of both species

Vocalizações de longo alcance de Alouatta fusca clamitans e Alouatta belzebul belzebul: estrutura e contextos / Long distance in Alouatta fusca clamitans and Alouatta belzebul belzebul: structure and contexts

Duas espécies de bugios foram estudadas coro o intuito tio esclarecer seus padrões de vocalizações tio longo alcance e as funções por estas assumidas. Registros de vocalizações e observações sobre contextos de emissão em Alouatta fusca clamitans Foram obtidos em Indaial, Santa Catarina. Registros de Alouatta belzebul belzebul foram obtidos em Sapé, Paraíba. O repertório de vocalizações de longo alcance das duas espécies é formado por sons roucos e graves, em geral de ata amplitude, que são emitidos em seqüências que podem durar vários minutos. Ocorrem amplas gradações dentro de cada tipo de vocalização, assim como entre diferentes categorias de vocalização. As emissões predominantes são os rugidos e latidos, sendo que a estrutura destas vocalizações parece refletir urna divergência funcional: latidos aparentam ser sinais graduados ele alarme agregativo ou de alerta, enquanto rugidos sinalizariam o Potencial de defesa de recursos dos emissores, sendo empregados em lutas ritualizadas por recursos ou defesa dos mesmos a longa distância. As observações contextuais feitas em A. f. clamitans dão suporte a estas hipóteses. As principais divergências entre as duas espécies ocorreram no uso e estrutura do rugido, que parece ser finais espontâneo em A. b. belzebul. Coros matinais de emissão de rugidos ocorrem em A. b. belzebul, mas não em A. f. clamitans. A divergência estrutural das vocalizações pode refletir adaptações próprias de cada espécie

Sentinels in Saltator atricollis (Passeriformes: Emberizidae)

I studied the existence of sentinels in Saltator atricollis in a 'campo-cerrado' (Brazilian savanna) during the breeding seasons of 1994-95 and 1995-96. Groups of this species consisted of two to seven birds (N = 25). Sentinels were present (mean sd) 62 percent 9 percent of the time, and most sentinel bouts lasted from less than one to six minutes (although in some occasions for more than 30 min.). Overlap of two or more sentinels occurred on average only 3.2 percent of the time with birds on guard. Sentinels commonly gave contact calls in the beginning and/or at the end of a sentinel bout. The group size had no effect on time with sentinels. However the encounter rate between raptors and groups significantly influenced the time guarded. The results of this study suggests that the ability of sentinels to detect predators may play a central role as an anti-predator device