Effects of photoperiod on reproduction of Siamese fighting fish Betta splendens

This study investigated the effect of different photoperiods (24 h of light (L):0 h of darkness (D); 20L:4D; 16L:8D; 12L:12D; and 8L:16D) on the reproduction and growth of Betta splendens. The results showed that spawning frequency was significantly higher in couples reared under 16L:8D and 12L:12D, in comparison with other treatments. The highest number of eggs per spawn was obtained under 16L:8D (544.76±375.23) and 12L:12D (471.13±261.52), and the lowest values were detected for 24L:0D (128.55±58.14) and 20L:4D (187.87±103.84). Fertility and fecundity also showed significantly higher average values in 16L:8D and 12L:12D when compared with 24L:0D and 20L:4D treatments. Egg volume and perivitelline space were significantly higher in 24L:0D treatments that showed the lowest numbers of eggs per spawn, while the vitelline volume did not show significant differences. Other variables such as breeders weight gain and condition factor (K) were not statistically different. Moreover, the final length varies according to photoperiod and gender. These results demonstrated a key role for the photoperiod upon B. splendens reproduction. The best reproductive performance is achieved under the photoperiods that best approached those that occur in spring and summer (16L:8D and 12L:12D), coinciding with their best seasons for reproduction.

Genetic relatedness among wild, domestic and Brazilian fighting roosters

Except for the meat- and egg-type strains used in commercial poultry farms in Brazil, there are no scientific reports about the origin of birds from the genus Gallus that have been introduced in this country with domestication or fighting purposes. Therefore, the aim of this study was to identify the position of the Brazilian Game Bird in the phylogenetic tree of the genus Gallus by nucleotide sequence analysis of the mitochondrial DNA D-loop region. The results indicate that fighting roosters comprise two different clusters within the species Gallus gallus domesticus. One of the clusters is related to the wild ancestors, while the other one is more related to the birds raised by the poultry industry. In conclusion, Brazilian fighting roosters have originated from the red jungle fowl (Gallus gallus) and belong to the subspecies Gallus gallus domesticus.

Correlation between the fighting rates of REM sleep-deprived rats and susceptibility to the 'wild running' of audiogenic seizures

Sleep-deprived rats exhibit defensive fighting as well as explosive flights very similar to the wild-running of audiogenic seizures. In order to determine why sleep deprivation is a common factor that facilitates both panic and convulsive manifestations, the present study was undertaken to investigate whether rats that display sleep deprivation-induced fighting (SDIF) are the same as those that are susceptible to audiogenic wild-running (WR). Twenty-eight male adult Wistar rats were divided into two groups assigned to two e-sleep deprivation for 5 days and had their SDIF evaluated in social experimental schemes. In the first, 18 subjects were submitted to REM grouping. After 1 week for recovery, their susceptibility to WR was tested in an acoustic stimulation trial ( 104 dB, 200 Hz, 60 S). Rats that did not present WR received a lactate infusion and were tested again by acoustic stimulation 40 min later. In the second experimental scheme, 10 subjects were initially evaluated for WR susceptibility and the number of SDIF was recorded in social grouping after I week. Three categories of WR-susceptibility were determined: WR-sensitive rats, intermediate WR-sensitive rats and WR-insensitive rats. T'he number of SDIF in each category was significantly different and there was a high positive correlation (r=0.89; Spearman test) between the number of SDIF and the level of WR-susceptibility. We conclude that the reasons why sleep deprivation exerts facilitatory effects on both panic and convulsive manifestations are due to overlappings of neural pathways responsible for both behavioral patterns and for the property of sleep deprivation to increase neuronal excitability. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Early social environment and the fighting behaviour of young Oreochromis niloticus (Pisces, Cichlidae)

This study examines the influence of early experience with different forms of aggressive behaviour on the fighting behaviour of young fish. Fry of the cichlid fish, Oreochromis niloticus, were raised from hatching in small groups consisting of a normal individual (the test fish) and either mutant conspecifics lacking the dorsal fin and thereby the ability to perform fin displays, or normal ones. Following a 63-day period of development in groups the test fish were confronted in their home tanks with an unfamiliar normal fish for 10 min. The fighting behaviour of the test fish was analyzed considering their previous group type (mutant or normal) and rank (alpha or beta). There was no difference between test fish in the rate and sequence of behaviour patterns used in fighting. However, test fish that had developed in mutant groups were rarely the first to bite in contests and had a longer latency to biting following the first bite of the stimulus fish than rest fish with normal experience. This finding is attributable to the form of aggressive behaviour experienced by the test fish during development but not to existing differences in the amount of aggression previously experienced, nor to previous rank, sex, or size relative to the stimulus fish. The results suggest that early experience influenced decision making by the test fish during the fight. The involvement of the fin displays and the possible mechanism of this influence are discussed.

Fighting by sleep-deprived rats as a possible manifestation of panic: effects of sodium lactate

Increased fighting is an effect of desynchronized sleep deprivation (DSD) in rats, and recently this behavior has been suggested to be spontaneous panic and equivalent to panic disorder. In the present study we tested this hypothesis by evaluating the effect of sodium lactate on this aggressiveness, because this substance is recognized to induce spontaneous panic attacks in patients. A total of 186 male albino Wistar rats, 250-350 g, 90-120 days of age, were submitted to DSD (multiple platform method) for 0, 4, or 5 days. At the end of the deprivation period the rats were divided into subgroups respectively injected intraperitoneally with 1.86, 2.98 and 3.72 g/kg of 1 M sodium lactate, or 1.86 and 3.72 g/kg of 2 M sodium lactate. The control animals were submitted to the same procedures but received equivalent injections of sodium chloride. Regardless of DSD time, sleep-deprived animals that received sodium lactate presented a significantly higher mean number of fights (0.13 ± 0.02 fights/min) and a longer mean time spent in confrontation (2.43 ± 0.66 s/min) than the controls (0.01 ± 0.006 fights/min and 0.12 ± 0.07 s/min, respectively; P<0.01, Student t-test). For the sodium lactate group, concentration of the solution and time of deprivation increased the number of fights, with the mean number of fights and mean duration of fighting episodes being greater with the 2.98 g/kg dose using 1 M lactate concentration. These results support the hypothesis that fighting induced by DSD is probably a spontaneous panic manifestation. However, additional investigations are necessary in order to accept this as a promising animal model for studies on panic disorder.

Effects of trophic poisoning with methylmercury on the appetitive elements of the agonistic sequence in fighting-fish (Betta splendens)

The aggressive display in Betta splendens is particularly prominent, and vital to its adaptation to the environment. Methylmercury is an organic variation of Hg that presents particularly pronounced neuro-behavioral effects. The present experiments aim to test the effect of acute and chronic poisoning with methylmercury on the display in Bettas. The animals were poisoned by trophic means in both experiments (16 ug/kg in acute poisoning; 16 ug/kg/day for chronic poisoning), and tested in agonistic pairs. The total frequency of the display was recorded, analyzing the topography of the agonistic response. The methylmercury seems to present a dose- and detoxification-dependent effect on these responses, with a more pronounced effect on motivity in acute poisoning and on emotionality in the chronic poisoning. It is possible that this effect could be mediated by alteration in the mono-amino-oxidase systems.

New ruthenium(II)/phosphines/diimines complexes: Promising antitumor (human breast cancer) and Mycobacterium tuberculosis fighting agents

The synthesis and characterization of ruthenium compounds of the type [RuCl2(P)2(N-N)] [(P)2 = (PPh3) 2, dppb = 1,4-bis(diphenylphosphino)butano; dppp = 1,3-bis(diphenylphosphino)propane; N-N = 5,5′-dimethyl-2,2′dipyridyl (5,5′-mebipy) or 4,4′-dimethyl-2,2′dipyridyl (4,4′-mebipy)] are described. The complexes were characterized using elemental analysis, UV-Vis and infrared spectroscopies, cyclic voltammetry, and X-ray crystallography. In vitro evaluation of the complexes, using the MTT methodology, revealed their cytotoxic activities in a range of 5.4-15.7 μM against the MDA-MB-231 breast tumor cells and showed that, in this case, they are more active than the reference metallodrug cisplatin. The in vitro antimycobacterial activities of the complexes had their Minimum Inhibitory Concentration (MIC) for MTB cell growth measured, by the REMA method. The MICs for these complexes were found to be between 12.5 and 25.0 μg/mL. The results are comparable with the second line drug cycloserine (MIC = 12.5-50.0 μg/mL), commonly used in the treatment of TB. © 2013 Elsevier Ltd. All rights reserved.

Metabolic parameters of rats prone to display wild-running of the audiogenic crisis and fighting induced by REM-sleep deprivation

Fundação de Apoio à Pesquisa do Estado de São Paulo (FAPESP)

Environmental enrichment reduces aggression of pearl cichlid, Geophagus brasiliensis, during resident-intruder interactions

Em lutas entre peixes residentes e intrusos, residentes geralmente vencem, provavelmente porque valorizam o território mais do que os intrusos. Nós aventamos a hipótese de que ambientes enriquecidos aumentam o valor da área em disputa, levando os residentes a defenderem mais violentamente ambientes enriquecidos de recursos do que ambientes empobrecidos, pois possuiriam mais motivação para mantê-lo. No entanto, no presente estudo, ao testarmos as interações entre intrusos e residentes em acarás, Geophagus brasiliensis, observamos que o enriquecimento ambiental reduz a agressividade e pode levar a cohabitação entre os peixes, sem luta. Adicionalmente, em nossos experimentos, o efeito da residência prévia ocorreu independente da condição de enriquecimento. A diminuição das interações entre os peixes e, consequentemente, a diminuição do nível de agressividade é aqui atribuída aos efeitos da diminuição da visibilidade entre os peixes devido ao aumento de complexidade do ambiente.

Sex group composition, social interaction, and metabolism in the fish Nile tilapia

O objetivo deste trabalho foi testar se grupos monossexuais de machos gastam mais energia e exibem perfil agonístico diferente de grupos formados por um macho e uma fêmea na tilápia-do-Nilo (Oreochromis niloticus). Tais diferenças são esperadas, pois machos e fêmeas competem por diferentes recursos reprodutivos. Foram utilizadas duplas de machos (MM) e duplas de macho-fêmea (MF) que permaneceram pareadas por 40 minutos. Durante esse período foi feito o registro da interação agonística (10 minutos iniciais e 10 minutos finais do pareamento) e determinado o gasto energético (consumo de O2) pelo Método de Winckler. A latência para o início dos confrontos (média ± DP, MM = 27,40 ± 25,15 s; MF = 14,22 ± 21,19 s; Mann-Whitney, U = 33,50, P = 0,21) e a freqüência de todas as unidades comportamentais (média ± DP, MM < 72,30 ± 25,29; MF < 73,50 ± 21,65.10/min; Mann-Whitney, P > 0,10) foram semelhantes entre os grupos MM e MF nos 10 minutos iniciais. Isso indica que cada intruso foi considerado um potencial competidor no início da interação. No entanto, a freqüência de ondulação (interação também exibida durante a corte) foi maior para o residente do grupo MF nos 10 minutos finais (média ± DP, MM = 3,56 ± 5,89; MF = 8,56 ± 4,00.10/min; Mann-Whitney, U = 15,50, P = 0,01). A freqüência de fuga, entretanto, foi menor para o intruso do mesmo grupo (média ± DP, MM = 3,90 ± 4,33; MF = 0,44 ± 0,96.10/min; Mann-Whitney, U = 23,50, P = 0,04). Além disso, o perfil agonístico no grupo MM foi composto por um maior número de itens comportamentais do que o MF (para residentes e intrusos). Apesar das diferenças comportamentais, o consumo de O2 não foi afetado pela composição sexual do grupo (média ± DP, MM = 1,93 ± 0,54; MF = 1,77 ± 0,46 mgO2.g peso seco-1.40/min; t-teste de Student, t = 0,71, P = 0,49).

Aggressive behavior in the genus Gallus sp

The intensification of the production system in the poultry industry and the vertical integration of the poultry agribusiness have brought profound changes in the physical and social environment of domestic fowls in comparison to their ancestors and have modified the expression of aggression and submission. The present review has covered the studies focusing on the different aspects linked to aggressiveness in the genus Gallus. The evaluated studies have shown that aggressiveness and subordination are complex behavioral expressions that involve genetic differences between breeds, strains and individuals, and differences in the cerebral development during growth, in the hormonal metabolism, in the rearing conditions of individuals, including feed restriction, density, housing type (litter or cage), influence of the opposite sex during the growth period, existence of hostile stimuli (pain and frustration), ability to recognize individuals and social learning. The utilization of fighting birds as experimental material in the study of mechanisms that have influence on the manifestation of aggressiveness in the genus Gallus might comparatively help to elucidate important biological aspects of such behavior.

Resistance of stored bean varieties to Acanthoscelides obtectus (Coleoptera : Bruchidae)

During bean seed storage, yield can be lost due to infestations of Acanthoscelides obtectus Say, the bean weevil. The use of resistant varieties has shown promising results in fighting these insects, reducing infestation levels and eliminating chemical residues from the beans. The expression of resistance to A. obtectus in bean varieties is frequently attributed to the presence of phytohemagglutinins, protease inhibitors and alpha-amylase, and especially to variants of the protein arcelin, which reduce the larval viability of these insects. To evaluate the effect of bean seed storage time on the resistance expression of bean varieties to A. obtectus, tests with seeds of three ages (freshly-harvested, 4-month-old, and 8-month-old) were conducted in the laboratory, using four commercial varieties: Carioca Pitoco, Ipa 6, Porrillo 70, Onix; four improved varieties containing arcelin protein: Are. 1, Arc.2, Arc. 3, Arc.4; and three wild varieties also containing arcelin protein: Arc. IS, Arc.3S, and Arc. 5S. The Arc.5S, Arc. IS, and Arc.2 varieties expressed high antibiosis levels against the weevil; Arc. I and Arc3S expressed the same mechanism, but at lower levels. The occurrence of oviposition non-preference was also observed in Arc.5S and Arc. IS. The Arc.3 and Arc. 4 varieties expressed low feeding non-preference levels against A. obtectus. The expression of resistance in arcelin-bearing, wild or improved varieties was affected during the storage of seeds, and was high under some parameters but low in others. The results showed that addition of chemical resistance factors such as protein arcelin via genetic breeding may be beneficial in improving the performance of bean crops.

Synthesis, characterization and antimycobacterial activity of Ag(I)-aspartame, Ag(I)-saccharin and Ag(I)-cyclamate complexes

The present work describes the synthesis and antimycobacterial activity of three Ag(I)-complexes with the sweeteners aspartame, saccharin, and cyclamate as ligands, with the aim of finding new candidate substances for fighting tuberculosis and other mycobacterial infections. The minimal inhibitory concentration of these three complexes was investigated in order to determine their in-vitro antimycobacterial activity against Mycobacterium tuberculosis, Mycobacterium avium, Mycobacterium intracellulare, Mycobacterium malmoense, and Mycobacterium kansasii. The MIC values were determined using the Microplate Alamar Blue Assay. The best MIC values found for the complexes were 9.75 mu M for Ag(l)-aspartame against M. kansasii and 15.7 mu M for Ag(I)-cyclamate against M. tuberculosis.

Digestibilidade de alimentos protéicos e energéticos para fêmeas de beta

Foram avaliados os coeficientes de digestibilidade aparente de MS, PB, energia bruta (EB) e EE de alimentos protéicos (farelo de soja e farinha de peixe) e energéticos (fubá de milho e farelo de trigo) para beta (Betta splendens). Fêmeas adultas foram alojadas em gaiolas e mantidas em dois aquários de fibra de vidro (30 peixes/aquário) para alimentação e dois para coleta de fezes, ambos de formato cônico e com capacidade para 30 L. Os resultados dos coeficientes de digestibilidade aparente de MS, PB, EB e EE foram, respectivamente, de 69,43; 72,52; 67,91 e 55,50% para farelo de soja; 60,67; 51,15; 75,55 e 58,26% para farinha de peixe; 63,88; 87,16; 77,61 e 50,40% para fubá de milho; e 61,06; 93,37; 58,17 e 65,51% para farelo de trigo. Os resultados obtidos neste estudo permitem otimizar a formulação de dietas práticas balanceadas, economicamente viáveis para a espécie.