Time spent close to a sexual partner as a measure of female mate preference in a sex-role-reversed population of the blenny<Emphasis Type="Italic"> Salaria pavo</Emphasis> (Risso) (Pisces: Blenniidae)

In most species females do not exhibit conspicuous sexual behaviours and female mate preferences are often measured by means of the time spent close to males. In spite of its widespread use, in only a few studies has this measure been validated as a reliable indicator of female mate preference. Sex-role-reversed species offer a better opportunity to test female preferences, as females usually court males. We tested in a sex-role-reversed population of the blenny Salaria pavo (Risso) if the time spent by females close to males related to the number of courtship displays directed towards males, and whether these measures of female preference reliably predicted matings. Females were simultaneously presented with two males behind a glass partition and the time spent close to each male was measured. We then allowed females to have access to the males' compartments and measured the courtship behaviours performed by females towards each male and recorded with which of the males females spawned. Females spent more time close to the male that subsequently received more courtship displays, and the preferred male had a more developed head crest. However, both measures of female preference failed to predict matings. Females were often attacked by males and probably had, in some occasions, to spawn with the less preferred male. Females that spawned with the previously preferred male had more swollen bellies than females that spawned with the less preferred male, suggesting a male preference towards more ripe females. These results validate the use of "time spent close to a sexual partner" as a measure of female preference in S. pavo. We argue that matings may not always reliably indicate mate preferences, particularly in the less choosy sex.Communicated by R. Serrão Santos     

Female preference for large males in sailfin mollies,<Emphasis Type="Italic"> Poecilia latipinna</Emphasis>: the importance of predation pressure and reproductive status

We examined the effect of predation risk on female association patterns in the live-bearing sailfin molly (Poecilia latipinna). We tested two classes of females, with and without the risk of predation by a green sunfish (Lepomis cyanellus): (1) postpartum females (maintained with males until visibly gravid, then isolated and tested within 24–48 h of dropping a brood); and (2) non-postpartum females (different females, isolated from males for >50 days). When there was no apparent risk of predation, postpartum females showed a significant preference for large over small males, whereas non-postpartum females showed no size preference at all. When there was an apparent risk of predation, postpartum females maintained their preference for larger males and non-postpartum females continued to show no preference for large or small males. These results suggest that reproductive status (receptivity) plays a greater role in mate preference than predation risk. For postpartum females, the cost of not choosing a preferred mate may outweigh the potential cost of predation. Non-postpartum females either do not benefit from mating or are being indecisive about mating and thus are less likely to be choosy whether or not a predator is present.Communicated by I. Schlupp     

Tasty figs and tasteless flies: plant chemical discrimination but no prey chemical discrimination in the cordylid lizard<Emphasis Type="Italic"> Platysaurus broadleyi</Emphasis>

Lizards use visual and/or chemical cues to locate and identify food. The ability to discriminate prey chemical cues is affected by phylogeny, diet, and foraging mode. Augrabies flat lizards (Platysaurus broadleyi) are omnivorous members of the lizard clade Scleroglossa. Within Scleroglossa, all previously tested omnivores are capable of both prey and plant chemical discrimination. At Augrabies Falls National Park, P. broadleyi feed on both insects (black flies) and plant material (figs), and as scleroglossans, are predicted to discriminate both plant and prey chemicals. However, Platysaurus broadleyi use visual, not chemical cues, to detect and capture black flies, which occur in large concentrations in the study area. We tested free-ranging individuals for the ability to discriminate insect and plant chemicals from controls. There was a significant stimulus effect such that lizards tongue-flicked fig-labelled tiles significantly more than the remaining stimuli, spent more time at the fig-labelled tile, and attempted to eat fig-labelled tiles more often than tiles labelled with control or insect stimuli. Platysaurus broadleyi is exceptional in being the first lizard shown to possess plant chemical discrimination but to lack prey chemical discrimination. We suggest that an absence of prey chemical discrimination may be a consequence of foraging behaviour and environmental effects. Because insect prey are highly clumped, abundant, and aerial, profitable ambushing using visual cues may have relaxed any selective pressure favouring insect prey chemical discrimination. However, a more likely alternative is that responses to figs are gustatory, whereas as prey chemical discrimination and plant chemical discrimination are usually mediated by vomerolfaction.Communicated by P.K. McGregor     

Immunohistochemical expression of pi class glutathione S-transferase and alpha-fetoprotein in hepatocellular carcinoma and chronic liver disease

OBJECTIVE: To determine whether tumor marker pi glutathione transferase (GST-pi) is expressed in hepatocellular carcinoma (HCC) and other chronic liver diseases and to compare its expression with that of alpha-fetoprotein (AFP). STUDY DESIGN: Samples used were formalin-fixed, paraffin-embedded liver tissues: normal (n = 3), chronic hepatitis B (n = 15), cirrhosis (n = 15) and HCC (n = 30). The expression of AFP and GST-pi was detected by using immunohistochemistry with the peroxidase-antiperoxidase method. AFP immunoreactivity was based on the cytoplasm of the hepatocytes, while GST-pi immunoreactivity was based on the nuclei of hepatocytes. RESULTS: In normal liver tissues, AFP was not expressed. However, there was strong staining of GST-pi in bile duct epithelium cells and weak staining in hepatocytes. Our results showed higher AFP immunoreactivity in cases of HCC (36.7%) as compared to cirrhosis (6.7%) and hepatitis B (0%), whereas GST-pi immunoreactivity was lower in cases of HCC (53.3%) as compared to cases of cirrhosis (100.0%) and hepatitis B (93.3%). Percent sensitivity of AFP determination for HCC was 36.7% as compared to 53.3% for GST-pi, thus making GST-pi a more sensitive marker for detection of HCC. This study showed a significant relationship between the intensity and percentage of cells stained in hepatitis B, cirrhosis and HCC for GST-pi immunoreactivity (P < .001, .001 and .05, respectively) but not for AFP (P > .05). Statistical analysis showed that there was no significant relationship between expression of AFP and GST-pi in cirrhosis and HCC cases. Hepatitis B virus infection in HCC cases showed a positive rate of 46.7%, with AFP staining positively in 42.9% of tissues and GST-pi staining positively in 57.1% of tissues. CONCLUSION: AFP is a diagnostic but rather insensitive tissue marker for HCC. However, the absence of AFP in benign chronic liver disease makes this marker useful in differentiating between HCC and other chronic liver diseases, whereas GST-pi can be used as a diagnostic marker for HCC as well as in detecting other chronic liver diseases.     

Coumarins from Malaysian Micromelum minutum

In a continuation of our study of the Rutaceae, detailed chemical investigation on Micromelum minutum (Rutaceae) collected from Sepilok, Sabah, Malaysia gave four new coumarins. The structures of the coumarins have been fully characterised by spectroscopic methods as 3",4"-dihydrocapnolactone 1, 2',3'-epoxyisocapnolactone 2, 8-hydroxyisocapnolactone-2',3'-diol 3 and 8-hydroxy-3",4"-dihydrocapnolactone-2',3'-diol 4.     

Mother–infant relationships and maternal estrogen metabolites changes in macaques (<Emphasis Type="Italic">Macaca fuscata,M. mulatta</Emphasis>)

This research assessed mother–infant relationships in rhesus and Japanese macaques living in analogous captive social groups, and monitored changes in the levels of excreted estrogen metabolites during the peripartum period. Each mother–infant pair was focally observed 3 h per week during the first 12 weeks of life of newborns. Fecal samples were collected twice a week from each mother, starting 4 weeks before delivery and ending 4 weeks after delivery. Infant-directed behaviors appeared to be consistently less protective/controlling and more rejecting in rhesus macaques than in Japanese macaques. Estrogen metabolite levels during the perinatal period were, on average, 3-fold higher in Japanese macaques and showed a sharp increase during the last weeks of pregnancy only in the Japanese macaque group. Considering the ecological and behavioral similarities between Japanese and rhesus macaques, the divergence between the two species in the onset and maintenance of maternal behavior was unexpected. This was possibly linked to the difference in the overall body size and life history, and to the striking divergence in estrogen metabolite variation during the peripartum period. Group size, social relationships, and average age of individuals in the two captive groups were not clearly involved in the recorded differences in maternal behavior. Electronic Publication     

A model of the biogeographical journey from<Emphasis Type="Italic"> Proto-pan</Emphasis> to<Emphasis Type="Italic"> Pan paniscus</Emphasis>

Pan paniscus is unique in the group of African apes because of its range south of the Congo River. Examination of the bio-geographical journey of the genus Pan to the species P. paniscus is important when discussing the evolution of African apes. This paper is a review of the paleo-geographic events, the zoogeography, and faunal sorting which influenced P. paniscus divergence from the Proto-pan ancestor within the recent Miocene through Pliocene Epochs, approximately 10–2 MYA. Finally, by elucidating modern day evidence of food plant forms in the southern periphery exploited by P. paniscus in the forest/savanna mosaic habitat, we are able to conclude with those extrinsic events that most influenced the occurrence and distribution of P. paniscus. Electronic Publication     

How fruit abundance affects the chimpanzee party size: a comparison between four study sites

We examined the relationship between fruit abundance and chimpanzee (Pan troglodytes) party size by comparing data from four study sites: the Kalinzu Forest Reserve, Uganda, the Djinji Camp and Guga Camp in the Ndoki Forest, Congo, and Kahuzi-Biega National Park, Democratic Republic of Congo. Although the difference in the fruit abundance between the sites was responsible for the difference in the party size between the sites, the seasonal changes in fruit abundance did not explain the changes in the party size in each study site. Across the four study sites, there were significant correlations of the mean and minimum of monthly party size with the mean of monthly fruiting-tree density, and a significant correlation of the maximum of monthly party sizes with the minimum of monthly fruiting-tree density. We proposed a hypothesis that (1) the monthly fruit abundance affects the monthly party size in the sites where the fruit availability is as low as to limit the party size during a major part of a year, while (2) the party size does not increase with the increase in the monthly fruit abundance, but is affected by other social factors, in the sites where the minimum of monthly fruit abundance is high enough for chimpanzees to form parties of an adequate size. Electronic Publication     

Violent coalitionary attacks and intraspecific killing in wild white-faced capuchin monkeys (<Emphasis Type="Italic">Cebus capucinus</Emphasis>)

During 12 years of observation, we have observed three confirmed and two inferred lethal coalitionary attacks on adult male white-faced capuchins (Cebus capucinus) by members of two habituated social groups at Lomas Barbudal Biological Reserve, Costa Rica. In one case, an alpha male was badly wounded and evicted from his group, and when later found by his former groupmates he was attacked by several of them and died less than 24 h later. In two other cases, lone extra-group males were mobbed by adult and immature males of a bisexual group. One victim's abdomen was torn open and he died less than 24 h later. A second victim was quite badly bitten but may have escaped. The fourth and fifth cases resulted from intergroup encounters. One victim lost the use of both arms but may have survived, whereas the other died of unknown causes within an hour of the attack. The observed death rate from coalitionary aggression at our site is approximately the same as that reported for eastern chimpanzees. Because at least three of the five observed incidents involved large coalitions attacking lone victims, they support the general hypothesis that imbalances of power contribute to intraspecific killing in primates. However, the occurrence of lethal coalitional attacks in a species lacking fission–fusion social organization poses a challenge to the more specific version of the imbalance-of-power hypothesis proposed by Manson and Wrangham in 1991 to explain chimpanzee and human intergroup aggression.