Seasonal variation in male alternative reproductive tactics.

Genetic parentage analyses reveal considerable diversity in alternative reproductive behaviours (e.g. sneaking) in many taxa. However, little is known about whether these behaviours vary seasonally and between populations. Here, we investigate seasonal variation in male reproductive behaviours in a population of two-spotted gobies (Gobiusculus flavescens) in Norway. Male two-spotted gobies guard nests, attract females and care for fertilized eggs. We collected clutches and nest-guarding males early and late in the breeding season in artificial nests and used microsatellite markers to reconstruct parentage from a subset of offspring from each nest. We hypothesized that mating, reproductive success and sneaking should be more prevalent early in the breeding season when competition for mates among males is predicted to be higher. However, parentage analyses revealed similar values of mating, reproductive success and high frequencies of successful sneaking early (30% of nests) and late (27% of nests) in the season. We also found that multiple females with eggs in the same nest were fertilized by one or more sneaker males, indicating that some males in this population engage in a satellite strategy. We contrast our results to previous work that demonstrates low levels of cuckoldry in a population in Sweden. Our results demonstrate marked stability in both the genetic mating system and male alternative reproductive tactics over the breeding season. However, sneaking rates may vary geographically within a species, likely due to local selection influencing ecological factors encountered at different locations.

Effects of VIE tagging and partial tissue sampling on the immune response of three-spined stickleback Gasterosteus aculeatus.

A 14 day experiment on effects of visible implant elastomer (VIE) tagging and spine-clipping of three-spined stickleback Gasterosteus aculeatus showed significant increases in immune response, particularly in the granulocyte:lymphocyte ratio, in both treatments and the sham control. A minimum two-week recovery after handling, anaesthesia, tagging and spine-clipping is recommended to minimize effect of manipulation on the immune system.

The genetics and genomics of Syngnathidae: pipefishes, seahorses and seadragons.

The goal of this review was to provide a historical overview of how molecular techniques have increased the understanding of the ecology and evolution of the family Syngnathidae (pipefishes, seahorses and seadragons). Molecular studies based primarily on mitochondrial DNA markers have proved their worth by elucidating complex phylogenetic relationships within the family. Phylogeographic studies, which have revealed how life-history traits and past climatic events shape geographic distributions and patterns of genetic variation within syngnathid species, also provide interesting case studies for the conservation and management of threatened species. The application of microsatellite DNA markers has opened a floodgate of studies concerned with the breeding biology of these fishes, which are interesting due to their unique reproductive mode of male pregnancy. Research in this area has contributed significantly to the understanding of mating patterns and sexual selection. Molecular markers may also be employed in studies of demography, migration and local breeding population sizes. Genomic studies have identified genes that are probably involved in male pregnancy and promise additional insights into various aspects of syngnathid biology at the level of the gene. Despite these advances, much more remains to be explored. Goals for future research should include: (1) a more inclusive phylogeny to resolve outstanding issues concerning the relationships within the family and higher order taxa, (2) a broader use of molecular studies to aid management and conservation efforts, (3) the inclusion of more genera in comparative behavioural studies and (4) the continued development of genomic resources for syngnathids to facilitate comparative genomic work.

Evidence of paternal nutrient provisioning to embryos in broad-nosed pipefish Syngnathus typhle.

In two experiments, radioactively labelled nutrients (either (3)H-labelled amino-acid mixture or (14)C-labelled glucose) were tube-fed to brooding male Syngnathus typhle. Both nutrients were taken up by the males and radioactivity generally increased in the brood pouch tissue with time. Furthermore, a low but significant increase of (3)H-labelled amino acids in embryos was found over the experimental interval (48 h), whereas in the (14)C-glucose experiment the radioactivity was taken up by the embryos but did not increase over the experimental time (320 min). Uptake of radioisotopes per embryo did not differ with embryo size. A higher uptake mg(-1) tissue of both (3)H-labelled amino acids and (14)C-labelled glucose was found in smaller embryos, possibly due to a higher relative metabolic rate or to a higher surface-area-to-volume ratio compared to larger embryos. Uptake in embryos was not influenced by male size, embryonic developmental advancement or position in the brood pouch. It is concluded that brooding males provide amino acids, and probably also glucose, to the developing embryos in the brood pouch.

Results of wellness examinations of 28 African hunting dog (Lycaon pictus) puppies at the Denver Zoological Foundation.

Since 2002 the Denver Zoological Foundation has produced 28 African hunting dog (Lycaon pictus) puppies in 3 litters (7, 14 and 7 pups) from the same dam and sire. Wellness examinations were performed on each puppy. The wellness examinations spanned the range of 6-14 weeks of age. During the wellness examinations, in addition to physical examinations and vaccinations, blood samples for complete blood counts and sera biochemistry were obtained. Weights, morphometric measurements, rectal cultures for enteric pathogens and dental eruption patterns were recorded. Blood samples from each age group were compared with adult values from the Denver Zoo. It was noted that animals from the 14-pup litter were 63.6% of the mean weight of the two 7-pup litters, but size differences (in, for example, total body length) were less apparent. Two organisms were recovered from rectal cultures, namely Yersinia enterocolitica (n = 2) and Plesiomonas shigelloides (n = 3). The following deciduous eruption patterns were also noted; at 6 weeks, 11-3, i1-3, C1, c1, P1-2 and p1-2 (n = 7) were present, at 9-10 weeks, P3 and p3 (n = 21), and finally at 12-14 weeks, P4 (n = 28).

Geographical variation in the mating system of the dusky pipefish (Syngnathus floridae).

Differences among populations in the intensity of sexual selection resulting from distinct genetic mating systems can lead to divergent morphological evolution and speciation. However, little is known about how genetic mating systems vary between populations and what factors may contribute to this variation. In this study, we compare the genetic mating systems of two geographically distinct populations of the dusky pipefish (Syngnathus floridae), a species characterized by polygynandry and male pregnancy, from the Atlantic Coast of Virginia and the Gulf Coast of Florida. Our results revealed significant interpopulation variation in mating and reproductive success. Estimates of the opportunity for selection (I), the opportunity for sexual selection (I(s)) and the Bateman gradient (beta(ss)) were higher among males in the Florida population than in the Virginia population, suggesting that sexual selection on males is stronger in the Florida population. The Virginia population is larger and denser than the Florida population, suggesting that population demographics may be one of many causal factors shaping interpopulational mating patterns. This study also provides evidence that the adult sex ratio, operational sex ratio, population density and genetic mating system of S. floridae may be temporally stable over timescales of a month in the Florida population. Overall, our results show that this species is a good model for the study of mating system variation in nature and that Bateman's principles may be a useful technique for the quantitative comparison of mating systems between populations.

Serum bupivacaine concentrations following wound infiltration in children undergoing inguinal herniotomy.

Serum bupivacaine concentrations were measured in 12 children who underwent elective herniotomy and who received analgesia in the form of wound infiltration. Mean (SD) peak concentration was 0.36 (0.14) micrograms/ml and time to peak concentration was 14.6 (7.2) minutes after infiltration of 1.25 mg/kg of bupivacaine. These concentrations are lower than those associated with other local anaesthetic blocks and well below potentially toxic levels. Wound infiltration provides a simple, effective and safe method of providing postoperative analgesia for hernia repair in children.

Haemodynamic changes after induction of anaesthesia and tracheal intubation following propofol or thiopentone in patients of ASA grade I and III.

Thirty-six ASA I patients received either propofol 2.25 (0.07) mg kg-1 (mean (SEM] or thiopentone 4.8 (0.18) mg kg-1, for induction of general anaesthesia together with fentanyl and a neuromuscular blocking drug. This technique was repeated in 12 ASA III patients, using propofol 1.8 (0.18) mg kg-1 or thiopentone 4.7 (0.37) mg kg-1. There was a significant decrease in systolic arterial pressure following induction of anaesthesia with both drugs; this was more pronounced after propofol, and in ASA III patients. Plasma noradrenaline concentrations increased after tracheal intubation only in the thiopentone group, but the pressor response to tracheal intubation was not attenuated by the use of propofol.

Postoperative absorption of controlled-release morphine sulphate. A study in patients given no parenteral opioids.

The absorption of morphine sulphate in a controlled-release formulation was studied in 12 patients who had undergone unilateral inguinal hernia repair under a light general anaesthetic and ilio-inguinal block. Serum morphine concentrations were measured serially and gastric emptying was assessed by measurement of paracetamol absorption. Three patients had delayed gastric emptying and impaired morphine absorption in the immediate postoperative period. Four hours later, there was a significant reduction in gastric emptying in eight patients who had normal paracetamol and morphine absorption in the immediate postoperative period.

Plasma catecholamine concentrations--changes after infiltration with local anaesthetic solutions and adrenaline during bat-ear surgery.

Plasma catecholamine concentrations were measured in 12 patients who had bilateral bat-ear surgery following infiltration of each ear with 2 ml 2% lignocaine with adrenaline 1:100,000. Venous blood samples were withdrawn before and at set intervals after infiltration. Plasma adrenaline concentration increased from 0.8 pmol/ml to a peak of 2.2 pmol/ml at 2 minutes after infiltration; this is an increase of 175%. There was no significant change in plasma noradrenaline concentration.

Periosteal ganglion case report and review of the literature.

The first reported case of a periosteal ganglion to be documented by computerized tomography is presented. The lesion was located on the shaft of the tibia and was unrelated to ligamentous and joint structures. A review of the literature reveals that the most common site for this lesion is the upper leg, as noted in our case; for that reason, periosteal ganglion should be included in the differential diagnosis of any soft tissue lesion in this location. CT may be more useful than plain films to demonstrate periosteal ganglion when cortical erosion is absent.