Reproductive Pair Research Articles

Effects of mitochondria-targeted plastoquinone derivative antioxidant (SkQ1) on demography of free-breeding Campbell dwarf hamsters (Phodopus campbelli) kept in outdoor conditions. reproduction and lifespan: explanation in the framework of ultimate loads.

We studied demographic effects of the mitochondria-targeted antioxidant SkQ1 on free-breeding Campbell dwarf hamsters (Phodopus campbelli, Thomas, 1905, Rodentia, Cricetidae) in an outdoor vivarium with seasonally varying day length and temperatures. The animals were kept in pairs from their young age. We removed litters from parental cages at their age of 25 days. Experimental hamsters received daily 50nmol/kg SkQ1 with water by oral dosing, whereas control animals received water. SkQ1 had no effect on the lifespan of either males or females in reproductive pairs. Mortality among females was higher than among males irrespective of SkQ1 treatment, this being related to higher costs of reproduction in females. However, SkQ1 accelerated breeding in pairs in the first half of the reproductive period of a year. Although there were no statistical differences in body mass of males and females between experimental and control animals during most of their life, SkQ1-receiving males had higher body mass at the end of their life. The opposite tendency was characteristic for old females. One-year-old males and females of the experimental and control groups showed no difference in intensity of immune response to sheep red blood cells. The dermal hypersensitivity response to phytohemagglutinin (test for T-cell immunity) was significantly higher in SkQ1-treated 1- and 1.5-year-old males. This was not true for females. There was a tendency toward increased density of the neutrophil population in blood in 1-year-old SkQ1-treated males. However, experimental males showed no difference from control males in the activity of the "peroxidase-endogenous hydrogen peroxide system" of neutrophils. The background level of stress estimated by the concentration of cortisol in blood serum was significantly lower in the SkQ1-treated males during autumn adaptive adjustment of the organism. A similar trend was also observed during the January frosts, when the background level of stress was rather high. We observed no differences between cortisol concentration in experimental and control animals during the reproductive period in early spring and mid-summer. We tend to interpret the absence of geroprotective effect of SkQ1 on free-breeding dwarf hamsters by its ability to intensify breeding. We previously demonstrated the ability of SkQ1 to increase the lifespan of non-breeding females.

EFFECTS OF CITRUS OIL VOLATILES ON THE REPRODUCTIVE BIOLOGY OF THE RICE MOTH, CORCYRA CEPHALONICA (STAINTON) (LEPIDOPTERA: PYRALIDAE)

Rice moth, Corcyra cephalonica (Stainton) (Lepidoptera: Pyrali dae) is an important pest of stored food su ch as cer e als, cereal products, oil seeds puls es dried fruits nuts and spices . A sharp reduction in percent egg hatchability was n oticed at 72 hours exposure of the volatile s in comparison to 6, 12, 24 or 48 hours e xposure period to th e vapo r action of 20, 40, 80, or 160 µl volume of Citrus oil. There was a marked decline in egg output and egg hatchability in reproductive pairs, whose larval development for the first 15 days/from 16 th day till 30 days/continuous till 30 days took place in an environment ema nating from 20, 40, 80 or 160 µl volume of this oil. A ppreciable reduction in egg laying capacity and egg viability was noticed at 6 hour exposure of the volatile s in comparison to 3 hour exposure period to the action of different volume s of this oil. Ther e was significant reduction in Glycogen level , Total lipids , Total protein and Total free amino acids level in testes and ovaries of adults following the ir expo sure to the action of selected volatile s for 6 hours , emanating from 20 , 40, 80 or 160 µ l volume of Citrus oil.

Population Growth Characteristics of Incipient Colonies of the Eastern Subterranean Termite, Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae)

Growth of Reticulitermes flavipes (Kollar) incipient colonies during their first year was documented via a monthly destructive sampling census of 15 unique colonies, each headed by an inbred primary pair, for a total of 180 colonies. King and queen biomass greatly decreased during the first 2 months, coinciding with egg production and colony foundation, but their biomass remained relatively constant thereafter. Three cohorts of eggs were produced, with the greatest number of eggs (mean = 14.5) during the first month. Larvae were present at 1 month, and workers were first observed at 2 months. The survival rate of the initial brood was less than 100%, most likely due to cannibalism. A single soldier was first noted in some colonies at 6 months. Offspring biomass was equal to that of the reproductive pair at the 2-month census, double at 3 months, and quadruple at 11 months. One-year-old colonies ranged in size from 20 to 40 individuals, with an average of 28.9 individuals; total colony biomass was 39.8 mg. The growth rate of these R. flavipes colonies was much slower than was reported in other studies, but our observations are consistent with previous models and suggestions regarding colony growth.

Genetic Analysis of Population Structure and Reproductive Mode of the Termite Reticulitermes chinensis Snyder

The subterranean termite Reticulitermes chinensis Snyder is an important pest of trees and buildings in China. Here, we characterized genetic structure and reproductive modes of R. chinensis from China for the first time. A total of 1,875 workers from 75 collection sites in Huanggang, Changsha and Chongqing cities were genotyped at eight microsatellite loci. Analysis of genetic clusters showed two subpopulations in Chongqing city. The Huanggang population showed a uniform genetic pattern and was separated from the other populations by the largest genetic distances (F ST: 0.17–0.20). In contrast, smaller genetic distances (F ST: 0.05–0.12) separated Changsha, Chongqing-1 and Chongqing-2 populations. Chongqing-1 was the only population showing a genetic bottleneck. Isolation by distance among colonies in the Huanggang population indicated limited alate dispersal or colony budding. Lack of isolation by distance among colonies within the populations of Changsha, Chongqing-1 and Chongqing-2, suggested long-range dispersal by alates and/or human-mediated transport. Overall, extended family colonies (73.91%) were predominant in all four populations, followed by simple (20.29%), and mixed family colonies (5.80%). Most simple families were headed by inbred related reproductive pairs in the Changsha population, while most simple families in the Chongqing-1 population were headed by outbred unrelated pairs. Simple families in the Huanggang population were a mixture of colonies headed by outbred or inbred reproductive pairs. The sample size of simple families in the Chongqing-2 population was too small to yield significant results. Extended families in all four populations were headed on the average by ≤10 neotenics. Mixed families likely originated from pleometrosis. Presence of heterozygote genotypes showed that all neotenic reproductives collected in addition from five field colonies in Wuhan city were sexually produced, suggesting that these colonies did not undergo parthenogenesis. This study contributes to better understanding of the variance of genetic structure and reproductive mode in the genus Reticulitermes.

Socially Adjusted Synchrony in the Activity Profiles of Common Marmosets in Light-Dark Conditions

Synchronized state of activity and rest might be attained by mechanisms of entrainment and masking. Most zeitgebers not only act to entrain but also to mask circadian rhythms. Although the light-dark (LD) cycle is the main zeitgeber of circadian rhythms in marmosets, social cues can act as weaker zeitgebers. Evidence on the effects of social entrainment in marmosets has been collected in isolated animals or in pairs where activity is not individually recorded. To characterize the synchronization between the daily activity profiles of individuals in groups under LD conditions, the motor activity of animals from five groups was continuously monitored using actiwatches for 15 days during the 5th, 8th, and 11th months of life of juveniles. Families consisting of twins (4 ♂♀/1 ♂♂) and their parents were maintained under controlled lighting (LD 12:12 h), temperature, and humidity conditions. Synchronization was evaluated through the synchrony between the circadian activity profiles obtained from the Pearson correlation index between possible pairs of activity profiles in the light and dark phases. We also calculated the phase-angle differences between the activity onset of one animal in relation to the activity onset of each animal in the group (ψon). A similar procedure was performed for activity offset (ψoff). By visual analysis, the correlation between the activity profiles of individuals within each family was stronger than that of individuals from different families. A mixed-model analysis showed that within the group, the correlation was stronger between twins than between twins and their parents in all families, except for the family in which both juveniles were males. Because a twin is an important social partner for juveniles, a sibling is likely to have a stronger influence on its twin’s activity rhythm than other family members. Considering only the light phase, the second strongest correlation was observed between the activity profiles of the individuals in the reproductive pair. Regarding the parameters ψon and ψoff, the juvenile/juvenile dyad had lower values than the other dyads, but these differences did not reach statistical significance in relation to all dyads. Comparing the results of the ψon and ψoff, and correlation indices, we suggest that the latter could detect differences between the animals that were not observed in the results of the phase-angle differences. These differences could be related to changes that occur during the active phase but not only in a particular phase, such as the temporal changes during the activity phase that characterize unimodal or bimodal patterns. Based on the differences in the correlations between individuals subjected to the same LD routine, we suggest that social cues modulate the circadian activity profiles of marmosets as a result of interactions between the animals within each group. Future studies are necessary to characterize the mechanisms of synchronization that are involved in this social modulation. (Author correspondence: carolina@cb.ufrn.br)

Determining Host Suitability of Pecan for Stored-Product Insects

A no-choice test was performed to determine survival and reproductive capacity of stored-product insect pests on pecan, Carya illinoensis (Wangenheim) Koch. Insects used were Indianmeal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae); sawtoothed grain beetle, Oryzaephilus surinamensis (L.) (Coleoptera: Cucujidae); red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae); lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae); and rusty grain beetle, Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae). Fifty adults of each beetle species or 10 reproductive pairs of P. interpunctella adults were placed in 0.5-liter containers with either whole-shell pecans, cracked-shell pecans, randomly selected in-shell pecans, pecan nutmeats, cracked wheat, or glass beads and held at 28 degrees C, 60-70% relative humidity, and 16:8 (L:D) photoperiod for 2, 4, 6, and 8 wk. Four replications of each insect-diet-interval combination were performed. Larvae of P. interpunctella, O. surinamensis, T. castaneum, C. ferrugineus, and adult P. interpunctella and O. surinamensis developed on cracked and nutmeat pecan diets. R. dominica did not complete reproduction on pecans. Knowledge that these pests can reproduce on stored pecan will assist pecan growers, accumulators, and storage facilities in preventing insect outbreaks on their product.

The Unusual Neotenic System of the Asian Dry Wood Termite, Neotermes koshunensis (Isoptera: Kalotermitidae)

In most lower termites, colonies are headed by neotenic reproductives of both sexes after the primary reproductives (i.e., the queen and king) are lost. The production of a neotenic sexual is inhibited by the presence of a primary reproductive of the same sex. We found an exception in the caste system of the dry wood termite Neotermes koshunensis (Kalotermitidae). The neotenic caste is exclusively male. Moreover, production of male neotenics is completely inhibited not only by the presence of a king but also by the presence of a queen. Therefore, it is likely to be difficult for N. koshunensis colonies to recover their reproductive pairs.

The hindgut lumen prokaryotic microbiota of the termite Reticulitermes flavipes and its responses to dietary lignocellulose composition

Reticulitermes flavipes (Isoptera: Rhinotermitidae) is a highly eusocial insect that thrives on recalcitrant lignocellulosic diets through nutritional symbioses with gut-dwelling prokaryotes and eukaryotes. In the R. flavipes hindgut, there are up to 12 eukaryotic protozoan symbionts; the number of prokaryotic symbionts has been estimated in the hundreds. Despite its biological relevance, this diverse community, to date, has been investigated only by culture- and cloning-dependent methods. Moreover, it is unclear how termite gut microbiomes respond to diet changes and what roles they play in lignocellulose digestion. This study utilized high-throughput 454 pyrosequencing of 16S V5-V6 amplicons to sample the hindgut lumen prokaryotic microbiota of R. flavipes and to examine compositional changes in response to lignin-rich and lignin-poor cellulose diets after a 7-day feeding period. Of the ~475,000 high-quality reads that were obtained, 99.9% were annotated as bacteria and 0.11% as archaea. Major bacterial phyla included Spirochaetes (24.9%), Elusimicrobia (19.8%), Firmicutes (17.8%), Bacteroidetes (14.1%), Proteobacteria (11.4%), Fibrobacteres (5.8%), Verrucomicrobia (2.0%), Actinobacteria (1.4%) and Tenericutes (1.3%). The R. flavipes hindgut lumen prokaryotic microbiota was found to contain over 4761 species-level phylotypes. However, diet-dependent shifts were not statistically significant or uniform across colonies, suggesting significant environmental and/or host genetic impacts on colony-level microbiome composition. These results provide insights into termite gut microbiome diversity and suggest that (i) the prokaryotic gut microbiota is much more complex than previously estimated, and (ii) environment, founding reproductive pair effects and/or host genetics influence microbiome composition.

59. Current status of tundra cranes species populations in Yakutia

Just two from four breeding species of cranes in Yakutia, Siberian Crane Grus leucogeranus and Sandhill crane Grus canadensis canadensis , are found in the most northern areas of the region, inhabiting the subarctic tundra of the lowland between rivers Yana and Kolyma. Siberian crane is represented by the eastern population in the region. This crane winters in China (Yangtze River downstream basin) and appears to be a typical species of the Siberian fauna and endangered bird of the world fauna. Sandhill crane is an expanding species of American fauna with wintering grounds in Texas (USA) and Mexico. This crane is in a process of active distribution in the northeastern Yakutia and related to rare endangered species of the region. Siberian cranes’ increase of the eastern population number has been observed since the late 1990s on the breeding ground, particularly in tundra of the River Indigirka basin (the number of crane pairs increased from 52 to 56 on the model site of 1314 km 2 ) and on the main wintering ground in Poyang Lake Nature Reserve in the southeast of China (it reached 4 thousand individuals), no doubt, was related to the active scientific and conservation work undertaken within the framework of international cooperation, with a reduction of disturbance factors in key areas of habitat. Nevertheless, the current status of the population is still estimated to be alarming. The optimal habitat of Siberian Cranes is lakeside lowlands and wetlands occupied by 21–26% of the breeding range. They are located outside of the regular spring flooding territories and in uneven and mosaic distribution. The birds inhabit mainly areas adjacent to large and medium-sized lakes, occupying no more than 50–60% of the areas suitable for their nesting. The water content increases in the territory because of the destruction and defrosting of tundra soils that leads to a reduction of the most optimum habitat for the population. An average home range size for a reproductive pair, including its breeding and feeding areas, is 7.3–16.5 or 10.6 km 2 . The rate of population growth (reproduction efficiency varies from 4.3–8.7 to 65–83.3%) allows us to assume that the absence of separate generations of birds which did not live to maturity was due to their very low number and natural losses. The front of the bird migration in Yakutia has a quite narrow corridor. This is especially noticeable in the middle Aldan River at fall where up to 50% of the eastern population is reported from the separate observation points. Siberian crane transit stops are much longer in China than in Russia, and the concentrations of birds are more numerous in China. Sandhill cranes continue to distribute in the western region of tundra and increase their numbers. At present, the range of this species almost completely coincides with that of the Siberian crane (approximately 82 km 2 ). The species number has grown tenfold and reached 56 pairs over the past 20 years on the model site in tundra of the River Indigirka basin.

Prey selectivity affects reproductive success of a corallivorous reef fish

Most animals consume a narrower range of food resources than is potentially available in the environment, but the underlying basis for these preferences is often poorly understood. Foraging theory predicts that prey selection should represent a trade-off between prey preferences based on nutritional value and prey availability. That is, species should consume preferred prey when available, but select less preferred prey when preferred prey is rare. We employed both field observation and laboratory experiments to examine the relationship between prey selection and preferences in the obligate coral-feeding filefish, Oxymonacanthus longirostris. To determine the drivers of prey selection, we experimentally established prey preferences in choice arenas and tested the consequences of prey preferences for key fitness-related parameters. Field studies showed that individuals fed almost exclusively on live corals from the genus Acropora. While diet was dominated by the most abundant species, Acropora nobilis, fish appeared to preferentially select rarer acroporids, such as A. millepora and A. hyacinthus. Prey choice experiments confirmed strong preferences for these corals, suggesting that field consumption is constrained by availability. In a longer-term feeding experiment, reproductive pairs fed on non-preferred corals exhibited dramatic reductions to body weight, and in hepatic and gonad condition, compared with those fed preferred corals. The majority of pairs fed preferred corals spawned frequently, while no spawning was observed for any pairs fed a non-preferred species of coral. These experiments suggest that fish distinguish between available corals based on their intrinsic value as prey, that reproductive success is dependent on the presence of particular coral species, and that differential loss of preferred corals could have serious consequences for the population success of these dietary specialists.

Life-history and thermal tolerance traits display different thermal plasticities and relationships with temperature in the marine polychaete Ophryotrocha labronica La Greca and Bacci (Dorvilleidae)

In order to gain insights into links between fitness and physiological function, the phenotypic plasticity of life-history traits and thermal tolerances has been investigated in a laboratory strain of the polychaete Ophryotrocha labronica acclimated to a broad range of temperatures. Reproductive pairs were kept in isolation for two months at one of six temperatures (10, 15, 20, 25, 30 and 35°C), and survival and a number of life-history traits recorded. Tolerance to heat and cold was assessed in individuals that survived the acclimation period by measuring upper and lower thermal limits. Life-history and thermal tolerance traits showed different relationships with temperature: generally non-monotonic for life-history and monotonic for thermal limits. The thermal history of the strain used in the study seemed to be partly responsible for this pattern, affecting the thermal responses of most life-history traits, but not those of the upper and lower thermal limits. Survival correlated positively with tolerance to cold but not with heat tolerance. This result supports the idea that tolerance to heat is under stronger selection in O. labronica, resulting in a lower level of plasticity for this trait. Some life-history features positively co-varied with tolerance to heat (e.g. body size), whilst in other cases reproductive traits showed apparent trade-offs with thermal limits. In all cases correlations amongst traits were apparently driven by their relationship with temperature. Even if we found no evolutionary trade-offs among the thermal responses of life-history traits and thermal limits, the strategies evolved by organisms to cope with thermal variability result from the mutual interaction of these traits, which plays a key role in defining organisms' responses to temperature changes and fluctuations.

Dispersal flight and colony development in the fungus-growing termites Pseudacanthotermes spiniger and P. militaris

Pseudacanthotermes spiniger and P. militaris are two African fungus-growing termites (Termitidae, Macrotermitinae) which may become pests in disturbed agrosystems where they often live in sympatry. To study their development and their reproductive strategies, colonies of both species were reared in the laboratory for 20 and 17 years, respectively, after their foundation from reproductive pairs. The first steps of development were in great part similar in both species, although P. spiniger favoured the defence during the juvenile period, while P. militaris tended to favour a rapid development. While P. spiniger colonies did not produce alates until year 7 of colony life, P. militaris colonies were able to produce a fertile progeny 4 years after their foundation. In contrast, major soldiers were more rapidly differentiated in the incipient colonies of P. spiniger. Dispersal flights occurred every year for 10 years in P. spiniger. In P. militaris, dispersal flights did not occur regularly although alates appeared yearly. The annual number of alates produced by P. spiniger increased with the colony age to reach a maximum of 25,000 individuals and global production of alates was estimated at ca. 150,000 individuals in the life of a colony. The longevity of P. spiniger and P. militaris colonies was around 20 years. These species were shown to be reproductively isolated by multiple pre-mating mechanisms. While chronological differences in dispersal flights contribute to reproductive isolation of the two species, the non-viability of experimental hybrid colonies also indicates the involvement of post-mating mechanisms of isolation.

Impact of combined action of Neem and Eucalyptus oil volatiles on different stages of Corcyra cephalonica (Lepidoptera: Pyralidae)

Combined action of neem (Azadiracta indica) and eucalyptus (Eucalyptus sp.) oil volatiles causes a sharp reduction in percent egg hatchability in rice moth, Corcyra cephalonica (Stainton) (Lepidoptera: pyralidae) when freshly laid eggs were exposed to these volatiles for 24 hours. A marked decline in egg output and egg hatchability in reproductive pairs, was observed whose larvae were allowed to develop in a programmed manner in an environment, laden with combined action of selected volumes of neem and eucalyptus oil or when both the sexes of these pyralids, were confined for the prescribed limited period, in such odorous environment. A significant reduction in glycogen, lipid and protein level and an increase in free amino acids was noticed in testes and ovaries of these pyralids, when breeding pairs were exposed to the selected volatiles for a period of six hours only.

A microsatellite-based test of the Reticulitermes speratus genetic caste determination model in Coptotermes lacteus

Coptotermes lacteus, a termite found in eastern Australia, is a central-site nester that constructs mounds up to 2 m in height. Mature colonies typically contain the primary king and queen, and up to a million or more worker and soldier offspring. Once a year, male and female nymphs are produced in approximately equal numbers and develop into new alates. Experimental removal of the queen in the field and subsequent mating of the king with a replacement queen, results in an unusual phenomenon whereby the production of female nymphs completely ceases, while the production of male nymphs, and workers of both sexes, continues. The proximate cause of this nymph male-bias is yet to be discovered. The production of male nymphs and workers of both sexes in de-queened C. lacteus colonies is equivalent to offspring production patterns in laboratory crosses of male nymphoid (nymph-derived) with female ergatoid (worker-derived) replacement reproductives in the related species Reticulitermes speratus. An X-linked genetically influenced caste determination (GCD) mechanism has been proposed to account for such offspring patterns in R. speratus. We examined microsatellite genotypes in C. lacteus to test a prediction arising from the R. speratus GCD model: that nymphs should result from reproduction by neotenics, rather than the primary pair. In five of six colonies examined, genotypes indicated that all workers and nymphs were derived from a single reproductive pair. In three of these cases, the primary queen was also located and examined; her genotype matched that inferred from worker and nymph genotypes. These results suggest that the GCD model proposed for R. speratus does not apply to C. lacteus, at least under field conditions. The male-nymph bias following queen removal therefore remains an unresolved issue in C. lacteus.

Міжвидова гібридизація і фактори її формування на прикладі теріофауни Східної Європи

Phenomenon of hybridization as a special type of interspecies relationships is considered in relation to mammalians of East-European fauna. Hybridization can be considered either as restoration of panmixia or as violation of isolation depending on the level of evolutionary differentiation of populations. Diversity of hybridization cases could be categorized in six main groups, analyzed separately. It is shown that principal aspect in the concept of hybridization is the presence of «trigger» mechanisms of this process. In case of experimental (incl. stock-raising) hybridization, the key factor is an artificial formation of reproductive pairs. In natural conditions, main factor provoking hybridization is the changing of species geographical ranges. The leading role in case of young species is played by the expansions of allospecies inside geographical ranges of their siblings. Territory of Eastern Europe is a zone of high concentration of cryptic biodiversity, as well as polygon for multipling expansions. The expansions associated with colonization of post-glacial zones (in the past) and agricultural landscapes (recently), and with similarly directed migrations of fauna are the result of global climate changes. Keywords: hybridization, interspecies relations, invasions, evolution.

Genetic Evidence Highlights Potential Impacts of By-Catch to Cetaceans

Incidental entanglement in fishing gear is arguably the most serious threat to many populations of small cetaceans, judging by the alarming number of captured animals. However, other aspects of this threat, such as the potential capture of mother-offspring pairs or reproductive pairs, could be equally or even more significant but have rarely been evaluated. Using a combination of demographic and genetic data we provide evidence that i) Franciscana dolphin pairs that are potentially reproductive and mother-offspring pairs form temporal bonds, and ii) are entangled simultaneously. Our results highlight potential demographic and genetic impacts of by-catch to cetacean populations: the joint entanglement of mother-offspring or reproductive pairs, compared to random individuals, might exacerbate the demographic consequences of by-catch, and the loss of groups of relatives means that significant components of genetic diversity could be lost together. Given the social nature of many odontocetes (toothed cetaceans), we suggest that these potential impacts could be rather general to the group and therefore by-catch could be more detrimental than previously considered.

Effect of roundup® (glyphosate formulation) in the energy metabolism and reproductive traits of Hyalella castroi (Crustacea, Amphipoda, Dogielinotidae)

Roundup(®) (glyphosate formulation) is a nonselective and posts emergent herbicide used for controlling aquatic weeds and different concentrations are used in cultures around the world. The objective of this investigation was to examine the effects of Roundup(®) (glyphosate formulation) on the biochemical composition, levels of lipoperoxidation, Na(+)/K(+)ATPase activity and reproductive traits in the Hyalella castroi. Amphipods were collected in summer 2009, in the southern Brazilian highlands. In the laboratory, the animals were kept in aquariums under controlled conditions for 7 days, and after this period they were exposed to 0.36, 0.52, 1.08 and 2.16 mg/l of glyphosate for 7 days. After the period of exposure, the animals were immediately frozen for determination of glycogen, proteins, lipids, triglycerides, cholesterol, levels of lipoperoxidation, and Na(+)/K(+)ATPase activity. During each day of the cultivation reproductive traits (number of reproductive pairs, ovigerous females and eggs in the marsupium) were observed. All concentrations of Roundup(®) induced significant decreases in all biochemical parameters and Na(+)/K(+)ATPase activity, and significant increase in lipoperoxidation levels. Showing this form a potentially toxic effect at very low concentrations, this pattern of results can lead to significant changes in trophic structure of limnic environments because these amphipods are important links in food chain in these habitats.

Evaluation of dietary microalgae for culture of the calanoid copepod Pseudodiaptomus pelagicus

A series of five experiments were conducted to evaluate the effects of various dietary microalgae on survival, reproduction, sex ratio, fecundity, time to first maturation, brood interval, brood size, total nauplii production, and population development of the calanoid copepod Pseudodiaptomus pelagicus. Three experiments utilized 10 reproductive pairs of adults cultured in 1 L beakers. In the first experiment, the microalga Isochrysis galbana (T-iso) was fed at five densities to determine the optimal density for production. In the second experiment, five microalgae, T-iso, Thalassiosira weissfloggi (Tw), Chaetoceros gracilis (Ch), Rhodomonas lens (Rh), and Tetraselmis suecica (Tet), were each fed at a carbon equivalency of 80,000 cells/mL of T-iso. In the third experiment, the same five microalgae were fed along with four mixed microalgae diets, consisting of T-iso/Tw and T-iso/Ch at two ratios, 50:50 and 75:25, all were fed at a carbon equivalency of 160,000 cells/mL of T-iso. The fourth experiment cultured individual pairs in 30 mL beakers to determine the effects of dietary microalgae on nauplii production, brood size, and brood interval. The fifth experiment cultured 100 early stage nauplii (N1–N3) until the population reached sexual maturity. The optimal density of T-iso was 160,000 cells/mL. At 80,000 cells/mL, Tw produced a significantly greater number of copepods than the other microalgal diets. In the 160,000 cells/mL experiment, total production with T-iso/Tw at 50:50 ratio was the highest and was significantly higher than all monoalgal diets except Rh. In general, the total number of copepods produced was greater with mixed algal diets than those attained with the monoalgal diets. Results of the nauplii growout experiment showed that the survival of nauplii to adult was highest with Rh and lowest with T-iso. Time to first maturity was significantly affected by dietary microalgae with T-iso being the slowest. The percentage of ovigerous females was significantly different among dietary microalgae, with T-iso and Ch exhibiting the lowest percentage. P. pelagicus can be successfully cultured with various monoalgal diets but results suggest that a mixed algae ration of T-iso and Tw will produce the greatest population growth.

Carbofuran-induced alterations in the energy metabolism and reproductive behaviors of Hyalella castroi (Crustacea, Amphipoda)

Continuous or pulse exposure to pesticides may have negative effects on non-target organisms, resulting in a number of pathological and disturbed biochemical processes, including changes in energy budgets. The objective of this investigation was to examine the potential effects of carbofuran on the biochemical composition (glycogen, proteins, total lipids, triglycerides and cholesterol), levels of lipoperoxidation, Na +/K +ATPase activity, and reproductive behaviors (number of reproductive pairs, ovigerous females, and number of eggs) in the amphipod Hyalella castroi. The amphipods were collected in spring 2007, in the southern Brazilian highlands. In the laboratory, the animals were kept in aquariums under controlled conditions for 7 days, and after this period were exposed to 1 or 10 µg/L of carbofuran for 7 days. After the period of exposure, the animals were immediately frozen for determination of glycogen, proteins, lipids, triglycerides, total cholesterol, levels of lipoperoxidation, and Na +/K +ATPase activity. During each day of culture, reproductive behaviors were observed. Carbofuran induced significant decreases in biochemical reserves (glycogen, proteins, lipids, triglycerides and cholesterol), a significant increase in lipoperoxidation levels, and a decrease in Na +/K +ATPase activity in both males and females. Studies of all the biochemical parameters seem to be quite promising, in order to assess and predict the effects of toxicants on non-target organisms. The results showed that reproductive behaviors may provide sensitive criteria for assessing ecotoxicological effects. H. castroi lives among rooted aquatic macrophytes, and we suggest that it is a sensitive species that could be used in monitoring studies.

Geographic distribution and possible taxonomic distinction ofCallicebus torquatuspopulations (Pitheciidae: Primates) in Peruvian Amazonia

Population densities of yellow-handed titi monkey (Callicebus torquatus) were estimated using transect census methods. Densities were 2.8 individuals/km(2 )in the upper Rio Itaya basin and 2.5 individuals/km(2) in the lower Rio Algodón basin. Group size varied from two to five individuals, with an average of 2.9 individuals per group at the Rio Itaya. Groups were generally composed of two adults, probably the reproductive pair, with progeny from one to three previous birth seasons. Although the Rio Itaya population is phenotypically identical to populations from the rivers Nanay and Tigre, it differs from population on the rivers Napo and Putumayo. This suggests the existence of two disjunct populations of C. torquatus in Peruvian Amazonia whose taxonomic status warrants further examination.