Pharmacokinetics of ceftriaxone in Green sea turtles (Chelonia mydas) following intravenous and intramuscular administration at two dosages

Green sea turtles are widely distributed in tropical and subtropical waters. Adult green sea turtles face many threats, primarily from humans, including injuries from boat propellers, being caught in fishing nets, pollution, poaching, and infectious diseases. To the best of our knowledge, limited pharmacokinetic information to establish suitable therapeutic plans is available for green sea turtles. Therefore, the present study aimed to describe the pharmacokinetic characteristics of ceftriaxone (CEF) in green sea turtles, Chelonia mydas, following single intravenous and intramuscular administrations at two dosages of 10 and 25 mg/kg body weight (b.w.). Blood samples were collected at assigned times up to 96 hr. The plasma concentrations of CEF were measured by liquid chromatography tandem mass spectrometry. The concentrations of CEF in the plasma were quantified up to 24 and 48 hr after i.v. and i.m. administrations at dosages of 10 and 25 mg/kg b.w., respectively. The C_max values of CEF were 15.43 ± 3.71 μg/ml and 43.48 ± 4.29 μg/ml at dosages of 10 and 25 mg/kg, respectively. The AUC_last values increased in a dose‐dependent fashion. The half‐life values were 2.89 ± 0.41 hr and 5.96 ± 0.26 hr at dosages of 10 and 25 mg/kg b.w, respectively. The absolute i.m. bioavailability was 67% and 108%, and the binding percentage of CEF to plasma protein was ranged from 20% to 29% with an average of 24.6%. Based on the pharmacokinetic data, susceptibility break‐point and PK‐PD index (T > MIC, 0.2 μg/ml), i.m. administration of CEF at a dosage of 10 mg/kg b.w. might be appropriate for initiating treatment of susceptible bacterial infections in green sea turtles.     

Incidental catch of the loggerhead turtle Caretta caretta off the Balearic Islands (western Mediterranean)

A survey, which included questionnaires for fishermen and the placement of observers onboard fishing vessels, was conducted to assess turtle catch off the Balearic Islands. The survey focused on those fishing vessels whose base port was in the archipelago and, hence, the catch of South-eastern Spain longliners moving in summer to the archipelago was not considered. The fishermen's perception was that the stock of loggerhead turtles is declining in the archipelago and that fishing activities are at least partially responsible for this trend. The observer reports indicated that the figures produced by the interviewees for catch per unit effort (CPUE) were reliable. Therefore, on the basis of these figures we calculated a total catch of 373 (95% CI: 365-308) loggerheads for 2001. Most turtles were caught in lobster trammel nets (196; 95% CI: 269-123) or drifting longlines (102; 95% CI: 111-93). Although the CPUE was much lower for the former, total catch was greater because of a larger fleet. Moreover, most loggerheads caught in lobster trammel nets were found dead when nets were hauled in, while no immediate mortality was observed in individuals caught in drifting longlines. This observation highlights the threat of trammel nets to loggerhead turtle populations. The estimated impact of the catches on the turtle population depends on the origin of the individuals inhabiting the region, which is yet to be established.     

蛇鳄龟稚幼龟温室高密度培育试验

[目的]为控制蛇鳄龟养殖成本,探索适合当地实际的效益型蛇鳄龟稚幼龟高密度培育技术。[方法]2012年9月～2013年4月,利用控温温室,人工控制气温31～33℃、水温30～31℃,稚龟放养密度50只／m2,采用“一次放足全程培育法”培育蛇鳄龟幼龟。[结果]经7个月的培育,稚龟成活率达91．8％,雌龟规格达500～750g,雄龟达450～550g;稚幼龟培育平均投入产出比1：1．35。[结论]该试验为蛇鳄龟在当地的养殖与技术推广提供了依据。     

Implications of conserving an ecosystem modifier: Increasing green turtle (Chelonia mydas) densities substantially alters seagrass meadows

Ecosystem modifiers have the ability to significantly alter the ecosystem they inhabit sometimes with serious consequences for their own populations. We evaluated the ability of green turtles (Chelonia mydas) to modify seagrass ecosystems by their foraging activity. This study was conducted in a seagrass-dominated lagoon in the Lakshadweep Islands, Indian Ocean, where a stable high-density congregation of green turtles is present. We determined a gradient of turtle density in the lagoon and measured the intensity of turtle herbivory across the gradient. We then measured the impact of increasing grazing on seagrass structural parameters, growth and flowering along this gradient. Our results indicate that turtles substantially change seagrass meadow structure (canopy height, shoot length, width and density), reduce flowering and can potentially even cause changes in the species composition of the meadow. We discuss the implications of these results for seagrass ecosystem function, green turtle movement and human attitudes. When conserving ecosystem modifiers like the green turtle, any management strategy needs to include a detailed knowledge of the roles these species play in the ecosystems they inhabit.     

Conserving the terecay (Podocnemis unifilis, Testudines: Pelomedusidae) through a community-based sustainable harvest of its eggs

The exploitation of South American river turtles as a food source has long been considered the main factor contributing to the decline of populations. Along a stretch of the Aguarico River (Ecuador), we investigated the spatial and temporal distribution of terecay (Podocnemis unifilis) nests, factors affecting nest outcome, and the effect of offering a reward for each hatchling captured on the pattern of egg consumption by the local human community. Flooding influence on egg mortality appears to be particularly important in this Amazonian region, destroying 63.1% of all nests. This amount of nests resulted more than sufficient to satisfy the local community’s consumption needs (28.2%). The proposed reward for each hatchling ensured the voluntary participation of the Cofan people in the terecay conservation project, leading to: (i) nests being harvested only from sites where there were likely no hatching possibilities, (ii) efficient management and protection of nesting beaches with abolition of poaching of nests and adult females, and (iii) transplantation of nests from sites that would be flooded (and whose yield exceeds human consumption). Therefore, we argue that in this area of Aguarico River there are both biologically and socially favourable conditions for the establishment of a sustainable harvest of terecay eggs. Possible factors determining high nest mortality due to flooding in this area, as well as opportunities to make the project evolve toward economic self-sustainability, will also be discussed.     

Do circle hooks reduce the mortality of sea turtles in pelagic longlines? A review of recent experiments

Circle hooks have been proposed as a means of reducing the by-catch mortality of sea turtles in pelagic longline fisheries to sustainable levels. I examine the efficacy of circle hooks as a sea turtle conservation measure by examining the results of field trials conducted in the western North Atlantic, the Azores, the Gulf of Mexico, and Ecuador. These experiments employed more than a million and a half hooks between 2000 and 2004 and, in general, were well designed, conducted and analyzed. Four of five experiments demonstrated a significant reduction in capture rate and/or hooking location, indicating that circle hooks would reduce overall mortality. In one trial, however, circle hooks reduced catches of target species to such a degree that their use was impractical. I conclude, therefore, that circle hooks have the potential to reduce the mortality of sea turtles captured in many (but not all) pelagic longline fisheries, but that they should be field tested in a rigorous experiment before they are required in any fishery. Circle hooks will not reduce mortality rates of sea turtles in every pelagic longline fishery; each case needs to be tested before this measure is adopted. Circle hooks reduce turtle mortality because of their shape and size and the ways that these parameters interact with the size of turtles interacting with the fishery. Circle hooks may cause a reduction in turtle mortality by decreasing the incidence of hook ingestion as well as reducing capture rate, particularly for loggerhead sea turtles.     

鳄龟人工繁殖试验研究

在自然温度下进行鳄龟人工繁殖研究,放养2~3冬龄的鳄龟126只,平均体重3.8kg,雌雄比2∶1,约3m2放养1只,种植凤眼莲调节水质,投喂鱼、禽畜内脏和配合饲料等进行强化培育,塘边设置产卵沙池,鳄龟交配、产卵顺利。2003年初次产卵,产卵率41.7%,2004年产卵率94.0%,共产卵2691枚,受精2172枚,受精率80.7%。采取室内恒温孵化,保持温度28~32℃、空气相对湿度85%~90%,用粒径0.6~1.0mm、含水量为3%~5%的细沙作孵化介质,人工孵化稚龟1829只,孵化率84.2%。     

Incidental captures of sea turtles by swordfish and albacore longlines in the Ionian sea

ABSTRACT:   Incidental catches in pelagic longline fishing pose a serious threat to sea turtle populations throughout the world's seas and oceans. In this work, carried out in the framework of the EC-DG-Fisheries 98/008 project, information on sea turtle catch rates from swordfish and albacore longline fishing activities observed in Italian waters off the Ionian Sea during 1999 and 2000, are reported. In addition, biometric data, health status, and tagging return rate of sea turtles captured are provided. A total of 200 sea turtles were caught (198 loggerhead turtles and 2 green turtles), comprising 0.5–15.7% of the total catch in number of individuals. The estimates of the sea turtles caught by the total fishing effort of both longlines in the whole study area were 1084 specimens in 1999 (95% CI = 667–1502) and 4447 specimens in 2000 (95% CI = 3189–5705). Although all sea turtles were released alive, nearly half of them had hooks that could not be removed and remained deeply embedded in the digestive tract.     

包膜赖氨酸对稚鳖生长性能的影响及机理探讨

试验选择平均体重为18.40 g稚鳖180只,分为3组(每组6个重复,每重复10只),分别饲喂赖氨酸缺乏的(赖氨酸水平1.51%),添加晶体赖氨酸和包膜赖氨酸(赖氨酸水平均为2.62%)等能等氮半合成饵料,试验期60d。结果表明,赖氨酸缺乏组鳖晒背率、惊吓逃跑率、特定生长率、肝脏赖氨酸-α-酮戊二酸还原酶活性较低,腐斑率和饵料系数高。添加包膜赖氨酸显著提高了鳖生活力,特定生长率和蛋白质效率,且作用效果优于晶体赖氨酸。赖氨酸缺乏组和晶体赖氨酸组鳖摄食后6 h内血清游离赖氨酸在2 h左右达到高峰水平,而包膜赖氨酸组在4 h左右达到高峰水平。说明包膜赖氨酸可延缓血清游离赖氨酸达到高峰浓度的时间,促进氨基酸的有效利用和蛋白质的合成。