Mangroves as filters of shrimp pond effluent: predictions and biogeochemical research needs

Preliminary estimates of the ratio of mangrove forest: shrimp pond area necessary to remove nutrients from shrimp pond effluent are made using budgets of nitrogen and phosphorus output for semi-intensive and intensive shrimp ponds combined with estimates of total net primary production in Rhizophora-dominated mangrove forests in tropical coastal areas. If effluent is delivered directly to mangrove forest plots, it is estimated that, depending on shrimp pond management, between 2 and 22 hectares of forest are required to filter the nitrogen and phosphorus loads from effluent produced by a 1 hectare pond. While such ratios may apply to small scale, integrated shrimp aquaculture — mangrove forestry farming systems, the variability in mangrove hydrodynamics makes it difficult to apply such ratios at a regional scale. Before mangroves can be used to strip shrimp pond effluent more research is required on the effects that high ammonia and particulate organic matter loads in pond effluent have on nutrient transformations in mangrove sediments and on forest growth.     

Life history aspects of the mayfly Siphlonurus typicus (Ephemeroptera: Siphlonuridae) with a new application for measuring nymphal development and growth

Little is known about the life history of mayflies that inhabit temporary ponds. The purpose of this study was to observe and quantify life histories attributes of Siphlonurus typicus, which is known to reside in temporary ponds. Weekly samples of nymphs were taken from two temporary ponds in eastern Connecticut from March to June, 1999. Individuals were graded into 11 maturity classes, based on developmental characteristics, as a means of predicting population maturity rates. Head capsule widths (HCWs) were used to determine if growth occurred between maturity classes. Degree days were found to be an excellent predictor for population maturity (r ²=0.963, p<0.0001). Nymphs that hatched earlier in the year had larger HCWs than nymphs that hatched later in the year, possibly because of different temperature regimes. The University of Connecticut Forest pond (UCF) population matured faster than the Merrow Meadows pond (MER) population, but both sexes of the UCF population tended to be smaller than their counter parts from the MER population. Sex ratios were female bias for the UCF population (1.35:1), but were not different for the MER population. Adult emergence and mating occurred from 27 May to 21 June. There was a positive relationship between number of eggs per female and female body length. Oviposition at both sites occurred directly on the ponds, pond inlets, and outlets, indicating that pond populations were the result of local migrants as well as permanent residents. Temperature was a determining factor of maturity and fecundity for Siphlonurus typicus.     

INTRASPECIFIC LIFE HISTORY VARIATION IN A POND SNAIL: THE ROLES OF POPULATION DIVERGENCE AND PHENOTYPIC PLASTICITY

Two approaches were used to determine the degree of divergence in life histories among populations of the pond snail, Lymnaea elodes. Juvenile snails were reciprocally transferred between ponds differing in permanence and productivity, and the resulting variation in life history traits was recorded. In a second experiment, parents and their offspring from both a vernal and a permanent pond population were reared in the same pond. Proximal factors had by far the greatest effects on life history traits in the transfer experiment, with snails reared in a more productive pond showing earlier reproduction at a larger size, higher fecundity, and longer life cycle length. Snails from the more uncertain pond in terms of drying date did reproduce at an earlier age and smaller size and grew less in each pond. However, these population differences, for the most part, disappeared when snails were reared for two generations in the same environment. Much of the intraspecific variation in life histories seen in this species must therefore be considered the result of phenotypic plasticity. I argue that the plasticity in life histories itself may be adaptive to this inhabitant of unpredictable, vernal ponds.     

海蜇-对虾-蛤仔综合养殖池塘的食物网

为了研究海蜇-对虾(中国明对虾、斑节对虾)-菲律宾蛤仔海水综合养殖池塘养殖生物的食性、营养级和池塘食物网结构,在2017年5—9月的养殖周期内,采集并检测池塘内各种饵料和4种养殖生物的碳、氮稳定同位素比值(δ¹³C、δ¹⁵N),并运用IsoSource线性混合模型分析了海蜇、中国明对虾、斑节对虾和菲律宾蛤仔的食物来源。结果表明: 海蜇的主要食物来源为浮游动物;中国明对虾和斑节对虾的主要食物来源为投喂的鯷鱼;菲律宾蛤仔的主要食物来源为浮游植物、底栖硅藻和对虾粪便。综合养殖池塘中菲律宾蛤仔的营养级范围为2.64～2.95,平均值为2.84;海蜇的营养级范围为2.78～3.27,平均值为3.06;斑节对虾的营养级范围为3.03～3.54,平均值为3.25;中国明对虾的营养级范围为3.76～4.40,平均值为3.95。在综合养殖池塘中,菲律宾蛤仔为初级消费者,海蜇为次级消费者,中国明对虾和斑节对虾为捕食者;菲律宾蛤仔在滤食两种对虾粪便的同时一定程度上改善了养殖池塘的水质。     

Reproductive tactics of four sympatric sticklebacks (Gasterosteidae)

Synopsis The life history traits (longevity, growth, age at maturity, fecundity, egg size and length of breeding season) were compared for four sympatric sticklebacks (Gasterosteidae). Significant differences occurred for growth, longevity, age at maturity and length of breeding season, but not for egg diameters. Differences in life history traits are interpreted in terms of mechanisms permitting the coexistence of these closely-related territorial fish. Egg numbers were lowest inApeltes quadracus and highest inGasterosteus aculeatus withGasterosteus wheatlandi andPungitius pungitius having similar and intermediate fecundities.     

Life history variation among female surfperches (Perciformes: Embiotocidae)

Synopsis Life history variation within the family Embiotocidae is extensive and involves differences in age of first reproduction, fecundity schedules, growth rates, longevity and size of young. Based on maximum reported body lengths, there are three distinct size groups among the family's 23 species. Small species do not exceed 215 mm TL, medium-size species attain 275 to 335 mm TL, and the large species attain 380 to 470 mm TL. The longevity oh surfperches varies from two to ten years, growth is indeterminate, and females of the medium-and large-size groups may delay first reproduction beyond age one. With one exception, all species show increasing length-specific fecundities. The life history characteristics of females differ among the three size groups. Relative to smaller species, the largest species have moderately high fecundity, delayed maturity and long life. Medium-size species have low fecundity, may delay maturity for 1 to 3 years and have intermediate life spans. Small species have generally higher, but variable, fecundity, do not delay maturity, and are short lived. Among the small North American species, the trend in fecundity varies inversely with environmental predictability. Fecundity is highest in the species which occupies highly seasonal freshwater environments. Coastal species produce moderately large broods and species which occupy stable deep water environments produce the smallest broods.     

POLYPHENISM IN SPADEFOOT TOAD TADPOLES AS A LOCALLY ADJUSTED EVOLUTIONARILY STABLE STRATEGY

I examined the evolutionary factors maintaining two environmentally induced morphs in ponds of variable duration. Larvae of New Mexico spadefoot toads (Scaphiopus multiplicatus) often occur in the same pond as a large, rapidly developing carnivorous morph and as a smaller, more slowly developing omnivorous morph. Previous studies revealed that carnivores can be induced by feeding tadpoles live fairy shrimp and that morph determination is reversible. Field and laboratory experiments indicated that the ability of an individual to become a carnivore or an omnivore is maintained evolutionarily as a response to variability in pond longevity and food abundance. Carnivores survived better in highly ephemeral artificial ponds, because they developed faster. Omnivores survived better in longer-duration artificial ponds, because their larger fat reserves enhanced postmetamorphic survival. The two morphs also occupy different trophic niches. Experimental manipulations of morph frequency in ponds of intermediate duration revealed that increased competition for food among individuals of the more common morph made the rarer form more successful. Morph frequency within each pond was stabilized at an equilibrium by frequency-dependent morph reversal, which reflected frequency-dependent natural selection on size at metamorphosis: larger metamorphs had higher survival, and individuals reared at a frequency above the pond's equilibrium frequency were smaller at metamorphosis than were individuals of that morph reared at a frequency below the pond's equilibrium. Because neighboring ponds often differed in pond longevity and food abundance, each pond possessed a unique equilibrium morph frequency. This implies that morph determination in Scaphiopus is a locally adjusted evolutionarily stable strategy (ESS).     

The old trout Salmo trutta in the pond

The last of 12 brown trout Salmo trutta stocked in a small pond in south‐east Norway in 1979 were caught in July 2011. These fish represent a curiosity regarding longevity and growth pattern, and ageing from otoliths was consistent with the known life history of this specimen. Despite almost total stagnation in growth since the age of 16 years, the testes were fully developed.     

海水混养池塘虾蛤肠道与养殖环境的微生物多样性

【背景】海水混养池塘环境微生物以及动物肠道微生物的群落结构已有研究,但对混养环境中多品种动物肠道与环境微生物群落的关系尚未见报道。【目的】研究海水虾蛤混养环境中微生物多样性以及与养殖动物健康之间的关系。【方法】采用Illumina高通量测序技术测定冬季莆田市北江养殖区2个混养池塘中水体、底泥以及虾蛤肠道的菌群结构。【结果】同一池塘水体与底泥之间、不同池塘水体或底泥之间的微生物结构存在一定的差异;同一养殖区2个混养池塘虾与蛤肠道微生物结构之间具有极高的相似性,与养殖环境存在显著的差异。微生物多样性和丰富度差异很大,表现出底泥水体肠道;虾蛤肠道微生物以厚壁细菌和γ-变形细菌为主;池塘水体以放线菌、α-变形细菌以及拟杆菌为主,底泥以γ-变形细菌和δ-变形细菌为主。养殖动物肠道微生物主要优势种为乳球菌属和假单胞菌属,池塘环境内存在较高丰度的黄杆菌类潜在致病菌,而在虾和蛤的肠道中基本未检出。2个池塘底泥硫还原细菌含量较高,增加了底质产生硫化氢等有害物质的风险。【结论】比较混养池塘中水体、底泥以及虾蛤肠道三者之间微生物群落结构的差异,揭示虾、贝混养模式微生物与养殖环境的关系,为池塘养殖虾、贝疾病防治和混养结构的优化提供参考。     

Mangroves and brackishwater pond culture in the Philippines

Around 50% of mangrove loss in the Philippines can be traced to brackishwater pond construction. The decrease in mangroves from 450 000 ha in 1920 to 132 500 ha in 1990 has been accompanied by expansion of culture ponds to 223 000 ha in 1990. The history of fishpond development in the country includes a government-sponsored fishpond boom in the 1950-g and 1960s, the proconservation decade of the 1970s followed by a shrimp fever in the 1980s. Production from brackisshwater ponds has increased from 15 900 mt worth P7.6 million in 1938 to 267 000 mt valued at P6.5 billion in 1990. On the other hand, the maximum valuation of over $11 000 ha^–1 yr^–1 for unmanaged and managed mangrove forests makes them economically on par with the most profitable pond farming systems. The loss of mangrove systems and their varied goods and services is the single most important consequence of brackishwater pond culture in the Philippines. Moreover, intensive shrimp farming is associated with other ecological and socioeconomic effects such as pollution of coastal waters and decline in domestic food crops. New legislation and enforcement of existing laws, conservation of remaining mangroves, massive rehabilitation of denuded mangrove areas, and promotion of sustainable aquaculture and fisheries are recommended.     

The evolution of life-history traits in parasitic and free-living platyhelminthes: a new perspective

Parasite life histories have been assumed to be shaped by their particular mode of existence. To test this hypothesis, we investigate the relationships between life-history traits of free-living and parasitic platyhelminthes. Using phylogenetically independent contrasts we examine patterns of interspecific covariation in adult size, progeny volume, daily fecundity, total reproductive capacity, age at first reproduction and longevity. The correlations obtained indicate a similar causal chain of life history variations for free-living and parasitic platyhelminthes. These results suggest that increased longevity favours delayed reproduction. Furthermore, growth pattern determines adult body size and age at maturity. For platyhelminthes, whether free-living or parasitic, the total reproductive capacity is found to be directly determined by the size of the worm. Within this group the parasitic way of life does not seem to influence the basic patterns of life history evolution. Received: 20 September 1997 / Accepted: 1 March 1998     

虾池清塘排出物沉积厚度对老鼠簕幼苗的影响

模拟直接排入红树林的虾池清塘排出物在林地的不同沉积厚度（0、2、4、8 cm）,研究其对培养424 d的红树植物老鼠簕（Acanthus ilicifolius）幼苗生长和生理的影响。清塘排出物的加入对老鼠簕幼苗茎高、基径、叶片数、叶面积、生物量和相对生长率等生长指标都有显著促进作用。总体长势表现为沉积厚度8 cm>4 cm> 2 cm>0 cm。生长指标显示只需少量清塘排出物的沉积（沉积厚度2 cm、4 cm）就能对幼苗的生长产生明显的促进作用,但大量排出物沉积的积累并不会带来更明显的促进作用。清塘排出物沉积的加入能显著提高叶片光合能力,尤其利于叶绿素a的合成。沉积厚度2 cm和4 cm时,幼苗叶片游离脯氨酸的积累并不显著,但丙二醛、可溶性糖、可溶性蛋白含量显著高于正常水平;沉积厚度8 cm则使叶片中游离脯氨酸、丙二醛和水溶性化合物均有大量积累;而叶片中抗氧化酶活性只有在大量沉积物加入（沉积厚度8 cm）时才显著低于对照组水平。总之,老鼠簕幼苗对清塘排出物沉积厚度4 cm以下具有较强的抗逆性和适应力,沉积厚度8 cm会使老鼠簕幼苗受到一定程度的逆境伤害,但本实验期间还未影响其生长。     

Life in 3-D: life history strategies in tunas, mackerels and bonitos

The scombrids (tunas, bonitos, Spanish mackerels and mackerels) sustain some of the most important fisheries in the world and their sustainable management depends on better understanding of their life history strategies. Here, we first assemble life history information on maximum size, growth, longevity, maturity, fecundity and spawning duration and interval for all scombrid species. Second we characterize their life history patterns and trait co-variation and evaluate how many principal axes of trait variation underlie scombrid life history strategies. Most of their life history variation can be explained along three axes or dimensions: size, speed, and reproductive schedule. Body size governs the first axis ranking species along a small-large continuum. The second axis was mostly influenced by time-related traits, such as longevity, growth rates, spawning duration, time between spawning events, ranking species along a slow-fast continuum of life histories. Scombrid species with the slowest life histories such as Atlantic bluefin tuna Thunnus thynnus and Atlantic mackerel Scomber scombrus tend to inhabit more temperate waters while species with faster life histories such as yellowfin tuna Thunnus albacares and short mackerel Rastrelliger brachysoma are typically found in more tropical waters. The third axis comprises the negative relationship between number of eggs produced at length of maturity and rate in gain of fecundity with size describing the schedule of reproductive allocation which reflects a fundamental trade-off between reproduction and growth. Finally, in addition we show that the life history strategies of scombrids conform more closely to the Periodic and Opportunistic strategists within the triangular model of fish life histories.     

Longevity of simultaneous operation of aquaculture and mangrove forestry as explained in terms of water and sediment qualities

A silvofishery system (SFS) of 5.2 ha, simultaneously combining aquaculture (shrimp, crab, and fish) and forestry, was studied to understand how the water/sediment qualities had remained viable for 30 years. The long life of this SFS pond contrasts sharply with a short life of many conventional, intensively managed shrimp ponds (5 years on average). Total ammonia nitrogen in the SFS water (0.06 mg l^?1) was much lower than the Thai environmental safety standard for shrimp ponds (1.0 mg l^?1) and approximately 0.05 % of an average conventional, intensively managed shrimp pond. Total organic nitrogen of the pond sediment was 1.47 mg g^?1 which was almost half of conventional, intensively managed shrimp ponds. The flux study revealed that NH₄–N was the dominant form of nitrogen, with lesser amounts of NO₂–N and NO₃–N, and that NH₄–N was being released from the sediment into the water. Nitrogen loss from the pond, which was regarded as the denitrification rate, was estimated to be 71.5 mgN m^?2 d^?1, corresponded to 55 % of the total nitrogen input. As the average denitrification rate in a conventional, intensively managed shrimp pond is 13.4 %, the SFS was shown to be relatively efficient in removing accumulated nitrogen from the pond. Assuming accepted feed conversion rates, 3,340 kg of feed would have been necessary for the amount of fishery production recorded during 5 May 2005 and 22 March 2006. However, only 380 kg of trash fish was added, representing a saving of 2,960 kg of feed. Such a saving could be attributed to detritus from the mangrove trees that have been growing within the pond and algae encouraged to bloom by the shallow water depth. Therefore, it is suggested that the efficient nitrogen removal due to the high denitrification rate as well as the reduced feed input from mangrove detritus substitution, have contributed to maintaining favourable water and sediment qualities, resulting in the longevity of SFS pond.     

Notes on the life history of the clam shrimp,Eulimnadia texana

Several life history measures (growth rate, egg production, molt frequency, age at maturity and lifespan) were measured on several clam shrimp hermaphrodites (Eulimnadia texana Packard) grown in a laboratory setting under optimal growth conditions. Growth rates were high early in life, and then dropped dramatically when egg production began (day 5–6). Early egg production was low, and increased until approximately day 7, after which production leveled off for several days. Reproductive senescence was noted after day 17, with clutch sizes continuously dropping until death. Average molts per day was approximately 1.1, and molting seemed to be more closely associated with egg production than with growth. Growth and egg production were negatively correlated, indicating a possible trade-off between these two traits. No other trade-offs were detected. These shrimp show typical early-colonist life history traits, displaying high initial growth, early reproduction at a high rate, and then early senescence and death. This revised version was published online in August 2006 with corrections to the Cover Date.     

Contrasting life history traits of invasive topmouth gudgeon (Pseudorasbora parva) in adjacent ponds in England

Two topmouth gudgeon Pseudorasbora parva populations were studied in adjacent ponds in Northwest England to determine the influence of density on the expression of their life history traits. Initial introduction into one of these ponds had been in 2000, with establishment of an abundant population (density in March 2005: 6.1 ± 3.2 m^?2). Their transfer into the adjacent pond only occurred during brief periods of seasonal connection; this population was of low abundance (density in March 2005: 0.6 ± 0.5 m^?2) and was still colonising the pond at the time of sampling. In the low‐density population, individuals were significantly faster growing, maturing earlier (generally in their first year of life) and more fecund at length and age (mean batch fecundity at 50 mm: 883 compared with 473 eggs). These traits were advantageous in maximising early life reproduction, facilitating their colonisation and population establishment, a process already completed in the high‐density population.     

微生态制剂改善对虾养殖池塘底质的效果

研究了在117 d的养殖周期中微生态制剂对南美白对虾池塘底质的改良效果.结果表明,与对照组相比,施用微生态制剂可使底质中总氮、总磷和硫化物的含量显著下降;总菌数量无显著变化,而芽孢杆菌、氨化细菌以及硫氧化细菌、硫还原细菌、弧菌数量差异显著,其中弧菌数量在施用微生态制剂处理和对照条件下分别为3.65×10³ cfu·g^-1和1.16×10⁵ cfu·g^-1.表明施用微生态制剂可以减少氮、磷、硫等营养物质的积累,改善池塘底质的菌相,为南美白对虾的健康养殖提供良好的池塘底质环境.     

Evolution of longevity through optimal resource allocation

Models of life history evolution predict optimal traits of a simplified organism under various environmental conditions, but they at most acknowledge the existence of ageing. On the other hand, genetic models of ageing do not consider the effects of ageing on life histroy traits other than fecundity and longevity. This paper reports the results of a dynamic programming model which optimizes resource allocation to growth, reproduction and somatic repair. A low extrinsic (environmentally caused) mortality rate and high repair efficiency promote allocation to repair, especially early in life, resulting in delayed ageing and low growth rates, delayed maturity, large body size and dramatic enhancement of survival and maximum lifespan. The results are generally consistent with field, comprative and experimental data. They also suggest that the relationships between maximum lifespan and age at maturity and body size observed in nature may be by-products of optimal allocation strategies.     

Microbial Flora of Pond-Reared Brown Shrimp (Penaeus aztecus)

Agar plate counts and microbial types are reported for brown shrimp reared in 2-acre natural marshland and in 0.5-acre artificial ponds during June to October 1970. Bacterial counts of pond-reared shrimp ranged from 5 × 10⁴ to 5.5 × 10⁶ per g. At final harvest in October, bacterial counts ranged from 2 × 10⁵ to 5.5 × 10⁶ per g. In marsh ponds, bacterial counts of shrimp and pond water were lowest in August when both water temperature and salinity were high. Coryneform bacteria and to a lesser extent Vibrio were the predominant isolates from fresh pond shrimp. Shrimp stored at 3 to 5 C for 7 days were acceptable as judged by appearance and odor. Between 7 and 14 days of refrigerated storage, bacterial counts increased sharply and about 50% of the samples became unacceptable. Refrigerated storage of pond shrimp caused increases in coryneform bacteria and micrococci and decreases in Vibrio, Flavobacterium, Moraxella, and Bacillus species. Pseudomonas species were not significant in fresh or stored pond shrimp. The microbial flora of pond water usually was dominated by coryneform bacteria, Flavobacterium, Moraxella, and Bacillus species.     

Dragonfly species richness on man-made ponds: effects of pond size and pond age on newly established assemblages

We studied the abundance and species richness of adult dragonflies in 11 artificial ponds which were recently established (within 2years). We found that the adult dragonfly assemblage patterns were influenced by pond size as well as pond age. The species richness was positively correlated with the pond size, which was because the distributional patterns of species were significantly nested according to pond area. The species richness was highly correlated with pond age in association with the vegetation cover within ponds. It was suggested that the species richness was enhanced by the increasing immigration rate of species which favor well-vegetated ponds.