Forced Copulations and Female Contact Guarding at a High Male Density in a Calopterygid Damselfly

Territorial males of Calopteryx damselflies court females on territories that contain oviposition substrates. Nonterritorial males try to mate without courtship but very rarely obtain matings because females fail to bring up their abdomen to engage genitalia. Here I report the results of observations made on a very high-density population of Calopteryx haemorrhoidalis in central Italy. Mating activity was intense, and during 40 h of observation in an 8-m section of the stream, 209 matings were recorded (a maximum of 17 matings h ^–1 ). Males were continuously disturbing ovipositing females and tried to achieve tandem forcibly. Of 84 cases, males achieved forced tandem in 53, and 49 ended with copulation. Forced tandems were the most common method to obtain a mating in this population (55% of 65 matings). Males guarded females after forced or courtship copulations and, in some cases, maintained physical contact with their mate, by perching on her wings. Confusion was common and males guarded nonmates frequently, which suggests that they were unable to recognize their mate individually.     

Alternative Male Spawning Tactics and Acoustic Signals in the Plainfin Midshipman Fish Porichthys notatus Girard (Teleostei,Batrachoididae)

The plainfin midshipman Porichthys notatus has two male reproductive morphs, ‘Type I’ and ‘Type II’, which are distinguishable by their physical traits alone. Type I males are eight times larger in body mass than Type II males and have a six-fold larger relative sonic (vocal) muscle mass than Type II males. In contrast, the testicles of Type II males are seven times larger than those of Type I males. This study demonstrates morph-specific patterns of reproduction, including acoustic signals, for Type I and II males. Field censuses of nests showed that only Type 1 males maintained nests. Type II males and females transiently appeared in these nests in association with each other. Infra-red video and hydrophone recordings in aquaria showed that Type I males maintained nests and readily vocalized. Long-duration ‘hums’ and sequences of short-duration ‘grunts’ were produced during advertisement and agonistic contexts, respectively. Humming Type I males attracted females to their nests, pair-spawned, and then guarded egg clutches alone. By contrast, Type II males neither acoustically courted females nor maintained available nest sites, but rather ‘sneak-’ or ‘satellite-spawned’ at the nests of Type I males. Type II males infrequently produced low amplitude, short duration grunts that were similar in spectral, temporal and amplitude characteristics to the grunts of females. Type II males appear to be obligate sexual parasites of the nest-building, mate-calling, and egg-guarding Type I males. The dimorphic body and vocal muscle traits of the two male morphs in the plainfin midshipman are thus paralleled by a divergence in their reproductive tactics and the properties of their acoustic signals.     

Male Courtship Sounds in a Teleost with Alternative Reproductive Tactics, the Grass Goby, Zosterisessor ophiocephalus

Male grass gobies show two alternative breeding tactics, territorial and sneaker, distinguished by body size and difference in ray elongation on the second dorsal fin. The larger males, with elongated fins, are territorial and emit sounds during courtship. Smaller males, without elongated fins, act as sneakers. Both large and small males produce sounds in the presence of a ripe female. Males produce a grunt, lasting about 300ms, made up of pulses repeated at a low rate (22–68pps). Pulse duration, number, and repetition rate, did not differ between the two male types, but dominant frequency and sound amplitude did. Dominant frequency had a strong, inverse relationship with body size, whereas sound amplitude showed a weak positive relation to body size. Male size, and not the particular reproductive male tactic employed, is the most important correlate of sound properties in this species.     

Chorusing Behaviour,a Density-dependent Alternative Mating Strategy in Male Common Toads (Bufo bufo)

Male chorusing behaviour was studied in a population of common toads (Bufo bufo) on the island of Öland south Sweden, and the functional role of male advertisement calling in this species was experimentally examined. Calling males were larger and heavier than non-calling males (t = 2.41, p < 0.025 and t = 2.36, p < 0.025, respectively). However, small males were also found to call. This indicates that large males persisted in calling for longer and/or called more often. The proportion of calling males decreased as population size increased during the breeding season, indicating that calling is a low density strategy. Females responded more readily to calls than males. There were insufficient data to determine if the dominant frequencies of advertisement calls were inversely correlated with male body size, however, this relationship was found for the similar release calls. Females were found not to discriminate between high and low frequency calls, but when given a choice between two calls of different sound pressure levels (SPL), females were attracted to the louder calls. Thus, the function of chorusing is to advertise the position of males to mate-seeking females when the population density is low.     

Lek Mating System and Large Male Aggressive Advantage in a Gall-forming Tephritid Fly (Diptera: Tephritidae)

Field and laboratory studies revealed that the mating system of a tephritid fly, Procecidochares sp., meets even the most stringent definition of lekking behavior. Mark-recapture and plant-preference experiments confirmed that newly emerged adult Procecidochares sp. left their larval host plant (Chrysothamnus nauseosus) and flew to Atriplex canescens. The flies used A. canescens solely as a mate encounter site. Sex ratios of emerging flies did not differ from unity, but sex ratios at the leks were extremely male-biased. An advantage for larger individuals in male-male aggressive encounters was quantified and observations suggested that females might be choosing mates based on outcomes of fights. Lekking behavior, previously reported among polyphagic tephritids, is considered exceptional for a monophagous species. Factors favoring a lek mating system in this species are discussed.     

Extremely Low Microsatellite Diversity but Distinct Population Structure in a Long-Lived Threatened Species,the Australian Lungfish Neoceratodus forsteri (Dipnoi)

The Australian lungfish is a unique living representative of an ancient dipnoan lineage, listed as ‘vulnerable’ to extinction under Australia’s Environment Protection and Biodiversity Conservation Act 1999. Historical accounts indicate this species occurred naturally in two adjacent river systems in Australia, the Burnett and Mary. Current day populations in other rivers are thought to have arisen by translocation from these source populations. Early genetic work detected very little variation and so had limited power to answer questions relevant for management including how genetic variation is partitioned within and among sub-populations. In this study, we use newly developed microsatellite markers to examine samples from the Burnett and Mary Rivers, as well as from two populations thought to be of translocated origin, Brisbane and North Pine. We test whether there is significant genetic structure among and within river drainages; assign putatively translocated populations to potential source populations; and estimate effective population sizes. Eleven polymorphic microsatellite loci genotyped in 218 individuals gave an average within-population heterozygosity of 0.39 which is low relative to other threatened taxa and for freshwater fishes in general. Based on F _ST values (average over loci = 0.11) and STRUCTURE analyses, we identify three distinct populations in the natural range, one in the Burnett and two distinct populations in the Mary. These analyses also support the hypothesis that the Mary River is the likely source of translocated populations in the Brisbane and North Pine rivers, which agrees with historical published records of a translocation event giving rise to these populations. We were unable to obtain bounded estimates of effective population size, as we have too few genotype combinations, although point estimates were low, ranging from 29 - 129. We recommend that, in order to preserve any local adaptation in the three distinct populations that they be managed separately.     

Intra-sexual Dimorphism in Male Mandibles and Male Aggressive Behavior in the Broad-Horned Flour Beetle Gnatocerus cornutus (Coleoptera: Tenebrionidae)

In the stored-product beetle, the broad-horned flour beetle, Gnatocerus cornutus (Fabricius), all males possess enlarged mandibles, widened gena, and a pair of small horns on the vertex, but females lack these completely. Observations of male-male interactions of G. cornutus showed that larger individuals won male-male fights, and that the mandibles were used as weapons. Morphological analysis based on the non-linearity test of Eberhard and Gutierrez's model (1991) showed that intra-sexual dimorphism in males was only found in the mandibles used in male-male combat, but not in the gena and horns. This beetle can be an ideal model for evolutionary studies of exaggerated weapons for male combat, because rearing successive generations and observing male fighting are easy.     

Alternative Female Choice Tactics in the Scorpionfly Hylobittacus apicalis(Mecoptera) and Their Implications

Females of the scorpionfly Hylobittacus apicalis choose mateson the basis of material benefits (nuptial arthropod prey size)and probably on the basis of genetic benefits males deliverat mating. Females feed on the male's prey throughout copulation.They prefer males with large prey as mates and often refusemales who present small prey. That females may value male geneticquality is suggested by differences in ability of males to obtainlarge prey, which if inherited would influence offspring fitness,and by females often terminating mating with males with smallprey before they transfer any sperm or a complete ejaculate.Females hunt only when males with prey are not available becausehunting exposes individuals to predators. Female Hylobittacusapicalis exhibit alternative mate choice tactics, which arecondition-dependent in expression and probably comprise a conditionalstrategy. Body size, recent feeding history, and male availabilitydetermine how discriminating an individual female actually is,and these conditions may determine the value of material andgenetic benefits in mate choice decisions. The results suggestthat female choice controls male behavior. When females becomechoosy, males are forced to obtain rare large prey despite theincreased risks to males associated with this behavior. The implications of the findings on H. apicalis are discussedin relation to condition dependent female choice patterns inother species and the evolutionary maintenance of female choice.     

Mating Systems and Male Size in Australian Hylaeine Bees (Hymenoptera: Colletidae)

The mating systems of seven previously unstudied members of the colletid bee genus Hylaeus Fabricius and one of Hyleoides Smith are described. Male mating tactics can be categorized as territorial (perched males defend flowers or other sites that attract receptive females) or non-territorial (patrolling males search for receptive females at flowering plants). The four species in which some territorial males occur are characterized by: 1. grappling fights among males for preferred perches; 2. territorial control by larger males; 3. the possession of prominent spines or other projections on the venter of the abdomen in larger males; and 4. the occurrence of some males that are as large as, or larger than, the largest females of their species (the ‘large-male phenomenon’). In contrast, the four species that lack territorial males are distinctive in that males: 1. do not engage in grappling contests; 2. lack abdominal weaponry; and 3. are smaller than the largest females of their species. In addition, we searched for the large-male phenomenon in museum collections of four species of Hylaeus that exhibit male abdominal spines (presumed to be the weapons used by territorial individuals) and two other species that lack these attributes (presumed non-territorial patrolling species). The results tend to support the sexual-selection-for-fighting-ability hypothesis, which argues that the evolution of unusually large males is a selective consequence of aggressive male—male competition for access to mates. The limitations of the present data set as a comparative test of this hypothesis are discussed.     

Molecular Proxies for Climate Maladaptation in a Long-Lived Tree (Pinus pinaster Aiton,Pinaceae)

Understanding adaptive genetic responses to climate change is a main challenge for preserving biological diversity. Successful predictive models for climate-driven range shifts of species depend on the integration of information on adaptation, including that derived from genomic studies. Long-lived forest trees can experience substantial environmental change across generations, which results in a much more prominent adaptation lag than in annual species. Here, we show that candidate-gene SNPs (single nucleotide polymorphisms) can be used as predictors of maladaptation to climate in maritime pine (Pinus pinaster Aiton), an outcrossing long-lived keystone tree. A set of 18 SNPs potentially associated with climate, 5 of them involving amino acid-changing variants, were retained after performing logistic regression, latent factor mixed models, and Bayesian analyses of SNP–climate correlations. These relationships identified temperature as an important adaptive driver in maritime pine and highlighted that selective forces are operating differentially in geographically discrete gene pools. The frequency of the locally advantageous alleles at these selected loci was strongly correlated with survival in a common garden under extreme (hot and dry) climate conditions, which suggests that candidate-gene SNPs can be used to forecast the likely destiny of natural forest ecosystems under climate change scenarios. Differential levels of forest decline are anticipated for distinct maritime pine gene pools. Geographically defined molecular proxies for climate adaptation will thus critically enhance the predictive power of range-shift models and help establish mitigation measures for long-lived keystone forest trees in the face of impending climate change.     

Male Migration in Barbary Macaques (Macaca sylvanus) at Affenberg Salem

We analyzed male migration during a 20-year period in the free-ranging Barbary macaque population of Affenberg Salem. Most natal migrations occurred around puberty, but only one third of all males left the natal group. Secondary group transfers were rare. All males immediately transferred to other bisexual groups. Migration rates were highest during periods with high adult female/male ratios within social groups. Immigrants highly preferred groups with fewer males of their own age than in the natal group, and many males immigrated into groups that had no male their own age. These groups originated from a skewed distribution of resident males during group fissions. A comparison of emigrants with their natal peers supports the inbreeding avoidance hypothesis as cause of emigration rather than the male competition avoidance hypothesis. Emigrants had no lower individual rank position and did not come from lower-ranking matrilines. Emigrants had more female maternal relatives, especially sisters. Males without female relatives almost never emigrated. Conversely, there is virtually no indication that emigrants were evicted from the natal group. Emigrants had no increased mortality. Paternity data revealed that the reproductive success of emigrants and natal males is similar, indicating that emigration had no reproductive cost. Many similarities between emigrants and natal males that separated from female maternal kin during group fissions suggest that inner migration during fissions is an alternative way to avoid maternal inbreeding. The mating system resulted in a genetic structure within social groups that largely diminished the chances for paternal inbreeding even without recognizing paternal kin.     

134 Cryopreservation of Chlamydomonas Reinhardtii (Chlorophyceae): A Cause of Low Viability at High Cell Density

Cryopreservation provides a convenient method for long term storage of living organisms. Current protocols allow the successful cryopreservation of a wide range of algae, although many strains remain recalcitrant to cryopreservation. Chlamydomonas reinhardtii , a species utilized in many molecular and biochemical studies, survives cryopreservation best at low cell density. We show that reduced viability at higher cell densities is caused by the accumulation of a substance released from C. reinhardtii into the culture medium during cryopreservation. A mutant strain of C. reinhardtii (cw10) with a greatly reduced cell wall did not release a substance inhibitory to wild type or cw10 C. reinhardtii during cryopreservation, and could be cryopreserved with the same viability regardless of cell density. The inhibitory substance is small (mw<1300), polar, heat-stable and organic. Chlamydomonas moewusii Gerloff and Chlamydomonas zebra Korschikov ex Pascher both produce substances that reduce the viability of cryopreserved C. reinhardtii . However, neither is affected by the inhibitory substance produced by themselves or C. rienhardtii. Pandorina morum (Müller) Bory and Volvox carteri f. nagariensis Iyengar are colonial Volvocalean algae related to C. reinhardtii that cannot be successfully cryopreserved. They both generate substances that inhibit C. reinhardtii during cryopreservation. The identification of the substance inhibitory to C. reinhardtii during cryopreservation should explain why this alga cryopreserves best at a low cell density, and may lead to protocols that facilitate the more successful cryopreservation of C. reinhardtii and related algae.     

Social polymorphism in the Australian small carpenter bee, Ceratina (Neoceratina) australensis

The bee tribe Ceratinini provides important insights into the early stages of sociality. Many arthropods exhibit behaviours precursory to social life, including adult longevity, parental care, nest loyalty and mutual tolerance, yet the origins of social behaviour are few. Here we describe the biology of a facultatively social bee, Ceratina (Neoceratina) australensis, which exhibits all of the preadaptations for successful group living, yet presents ecological and behavioural characteristics that seemingly disfavour frequent colony formation. This species is socially polymorphic with both solitary and social nests collected in sympatry. Social colonies consist of two foundresses, one contributing both foraging and reproductive effort and the second which remains at the nest as a passive guard. Cooperative nesting provides no overt reproductive benefits over solitary nesting in this population, although brood survival tends to be greater in social colonies. Maternal longevity, subsociality and bivoltine nesting phenology in this species favour colony formation, while dispersal habits and offspring longevity may inhibit more frequent social nesting in this and other ceratinines.     

Social and maintenance behaviour in two Australian ocypodid crabs (Crustacea: Brachyura)

The feeding, burrowing and fighting behaviour and courtship display of the two ocypodids Heloecius cordiformis (H. Milne Edwards) and Hemiplax latifrons (Haswell) are described from daytime observations in the field over a two-year period and from four months study under laboratory conditions. The behaviour of the two species is compared with that of other ocypodid crabs. Heloecius cordiformis and Hemiplax latifrons live intertidally in estuaries in semi-permanent burrows and feed on detritus sifted from the mud and sand by the mouth-parts. The two species each possess considerably stereotyped patterns of behaviour, particularly in relation to fighting and courtship display in which the two differ most. The courtship display of Heloecius cordiformis closely resembles that of vertically waving, narrow-fronted species of fiddler crabs (genus Uca). The fighting behaviour of Hemiplax latifrons is similar to that of the New Zealand Hemiplax hirtipes (Jacquinot) which apparently lacks courtship display.     

Secreted Progranulin Is a Homodimer and Is Not a Component of High Density Lipoproteins (HDL)

Progranulin is a secreted glycoprotein, and the GRN gene is mutated in some cases of frontotemporal dementia. Progranulin has also been implicated in cell growth, wound healing, inflammation, and cancer. We investigated the molecular nature of secreted progranulin and provide evidence that progranulin exists as a homodimer. Although recombinant progranulin has a molecular mass of ∼85 kDa by SDS-PAGE, it elutes in fractions corresponding to ∼170–180 kDa by gel-filtration chromatography. Additionally, recombinant progranulin can be intermolecularly cross-linked, yielding a complex corresponding to a dimer (∼180 kDa), and progranulins containing different epitope tags physically interact. In plasma, progranulin similarly forms complexes of ∼180–190 kDa. Although progranulin partially co-fractionated with high density lipoproteins (HDL) by gel-filtration chromatography, we found no evidence that progranulin in mouse or human plasma is a component of HDL either by ultracentrifugation or by lipid binding assays. We conclude that circulating progranulin exists as a dimer and is not likely a component of HDL.     

Social Status and Plasma-Testosterone-Titers in Male Guinea Pigs (Cavia aperes f. porcellus)

The relationship between social status and testosterone (T) titers was studied in male guinea pigs living in a) either one group of 12 males and 12 females for 14–20 months in a 7.86 m² enclosure or in b) five groups of 3 males and 2 females for four months in 3.00 m² enclosures. As described in the literature the social structure of the large group was mainly characterized by long-term male-female associations and spatial preferences whereas in the small groups the linear rank-order between the males was the most obvious element. In all groups the rank-position was positively correlated with the amount of courtship bouts displayed. Fighting occurred only in the large group and in one small group where a challenge to the alpha-position took place. Here the highest ranking males showed highest T-titers in their groups. In those four groups where no fighting occurred rank-position and amount of courtship behaviour displayed was uncorrelated to plasma-T-titers. Our findings suggest that endogenous levels of T only reflect the highest ranking males' social status when their social position is challenged. When dominance relations are resolved and stabilized a male's rank-position and its amount of courtship behaviour displayed appear independent of plasma-T-levels in guinea pigs.     

Evolution of the Mitochondrial Genome in Mammals Living at High Altitude: New Insights from a Study of the Tribe Caprini (Bovidae,Antilopinae)

Organisms living at high altitude are exposed to severe environmental stress associated with decreased oxygen pressure, cold temperatures, increased levels of UV radiation, steep slopes, and scarce food supplies, which may have imposed important selective constraints on the evolution of the mitochondrial genome. Within mammals, the tribe Caprini is of particular interest for studying the evolutionary effects of life at high altitude, as most species live in mountain regions, where they developed morphological and physiological adaptations for climbing. In this report, we analyzed the complete mitochondrial genome of 24 ruminants, including 20 species of Caprini. The phylogenetic analyses based on 16,117 nucleotides suggested the existence of a new large clade, here named subtribe Caprina, containing all genera, but Pantholops (Pantholopina), Capricornis, Naemorhedus, and Ovibos (Ovibovina). The alignment of the control region showed that all Caprini have between two and four tandem repeats of ~75 bp in the RS2 region, and that several of these copies emerged from recent and independent duplication events. We proposed therefore that the maintenance of at least two RS2 repeats in the control region of Caprini is positively selected, probably for producing a higher number of D-loop strands 3′-ending at different locations. The analyses of base composition at third-codon positions of protein-coding genes revealed that Caprini have the highest percentage of A nucleotide and the lowest percentage of G nucleotide, a pattern which suggests increased rates of cytosine deamination (C→T transitions) on the H strand of mtDNA. Two nonexclusive hypotheses related to high-altitude life can explain such a mutational pattern: more severe oxidative stress (ROS) and higher metabolic rates. By comparing the relative rates of nonsynonymous and synonymous substitutions in protein-coding genes, we identified that Caprini have higher levels of adaptive variation in the ATPase complex. In addition, we detected several changes in mitochondrial genes that should be tested for their potential role in mountain adaptation. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Postcopulatory Behavior in Libellula pulchella Drury (Odonata: Libellulidae) and Female Tactics for Avoiding Male Interference with Oviposition

Postcopulatory behavior was studied in Libellula pulchella, a North American dragonfly in which ovipositing females face frequent harassment by unpaired males seeking matings. Although males performed noncontact guarding of their mates after copulation, females received minimal protection since their guarders tended to leave on extended chases of other males when harassment was intense. Ovipositions by unguarded females were even more likely to be terminated by harassment and were disrupted sooner. Female tactics to minimize interference included rapid escape flights, repeated return visits to the water within short time periods, perching when severerly harassed, and proceeding with mating when clasped. Female use of multiple oviposition sites is discussed in the context of guarding effectiveness and mate recognition by males.