A comparison of the fatty acid profiles of adult tissues,and newly hatched,fed and starved Lysmata amboinensis larvae

This study evaluated the lipid content and fatty acid (FA) profile of the hepatopancreas, ovaries and tail muscle of Lysmata amboinensis broodstock, as well as newly hatched larvae subjected to a period of starvation or feed from hatch to Zoea 2. The hepatopancreas had a high lipid content, confirming its role as a process and storage organ in L. amboinensis. Lipids were also a major component of ovarian dry weight, in agreement with reports on other crustaceans during maturation. The tail muscle, being a functional rather than a storage organ, contained low total lipids and was the tissue that closely resembled the FA profile of the newly hatched larvae. Saturated fatty acids (SFAs) and highly unsaturated fatty acids (HUFAs) were the most abundant components of the lipid profiles in broodstock and larvae. The HUFAs docosahexaenoic and eicosapentaenoic were preferentially retained during nutritional stress, confirming their importance for marine cleaner shrimp during early larval development. It appeared polyunsaturated fatty acid and HUFA requirements were met through the larval diet. The SFAs stearic and palmitic were abundant in adult tissues and larvae, whereas monounsaturated fatty acids may have been preferentially catabolized to meet energetic and metabolic larval requirements.     

几种天然饵料对清洁虾亲虾繁殖的影响

采用6种天然饵料喂养清洁虾亲虾,分析其对亲虾性腺发育、繁殖性能以及受精卵质量的影响。性腺发育试验发现,投喂6种不同饵料亲虾性腺发育周期差异显著(P<0.01),最长的为鱼肉组(12.82±1.91)d,最短的为卤虫无节幼体组(11.46±1.76)d;卤虫无节幼体与桡足类组性腺指数、干物质含量及总蛋白质含量随着性腺发育显著增加(P<0.01),增加均在2倍左右。繁殖性能与受精卵质量结果表明,鱼肉组(3 357±621)(粒/g)亲虾相对怀卵量最大,卤虫无节幼体组最小(1 829±213)(粒/g);卤虫无节幼体[(0.110 9±0.016 3)mm3]组亲虾受精卵体积最大,乌贼组最小[(0.096 2±0.014 0)mm3];鱼肉组[(37.33±1.75)μg]的受精卵干重最大,虾肉组最小[(31.00±1.26)μg];桡足类组蛋白质绝对含量[(367.17±25.68)mg/g]在干物质中所占比例(72.34%)最高。此外,6个饵料组中所有亲虾在各抱卵周期内抱卵率与抱卵间期无显著差异。     

Effect of different diets on larval production, quality and fatty acid profile of the marine ornamental shrimp Lysmata amboinensis (de Man, 1888), using wild larvae as a standard

The present work evaluates the influence of broodstock diets [Marine Cuisine^®– MC, MC supplemented with highly unsaturated fatty acid- (HUFA) enriched Artemia biomass – MC + AB, and MC supplemented with squid – MC + S] on larval production, newly hatched and early zoeal stage survival and fatty acid profile of newly hatched larvae of Lysmata amboinensis . These parameters are compared with those from larvae hatched from embryos spawned in the wild. The number (±SE) of larvae produced with MC and MC + S (1077 ± 219 and 1103 ± 184, respectively) was similar to that in broodstock carrying embryos spawned in the wild (1224 ± 111), while those fed MC + AB displayed significantly lower values (1044 ± 161). Larvae produced with MC + AB displayed lower survival for all starvation periods, while larvae spawned in the wild displayed the highest survival. No larvae resisted 144 h of starvation and none moulted to zoea II. The fatty acid comparison revealed that larvae from embryos spawned in the wild displayed the highest levels of DHA, as well as higher DHA/EPA and n -3/ n -6 ratios. These results suggest that broodstock diets commonly used to promote ornamental shrimp's maturation (based on mixed frozen components) are far from being optimal.     

海洋观赏虾类清洁虾胚胎发育的形态学观察

在实验室水温(26±1)℃、盐度(30±1)的条件下,对清洁虾(Lysmata amboinensis)胚胎发育过程中的形态学变化和发育时间进行研究。结果表明,清洁虾的胚胎发育过程可以分为9个主要阶段:受精卵、卵裂期、囊胚期、原肠期、无节幼体发生期、复眼色素形成前期、复眼色素形成后期、孵化前期和孵化期。胚胎大小在发育早期无显著变化,约为0.6 mm,进入孵化期时,胚径开始显著增大,可达0.9 mm;发育过程中胚胎的颜色逐渐加深,呈现出浅绿色、深绿色、深黄色、黄褐色的变化趋势;在26℃水温条件下,整个胚胎发育过程需13 d左右。本研究旨在为清洁虾人工育苗生产提供理论依据。     

光照对红条鞭腕虾繁殖性能及饵料对其幼体生长发育的影响

为了深入了解光照对红条鞭腕虾(Lysmata vittata)亲虾抱卵情况的影响,本研究通过将正常光照组(12L∶12D)亲虾的抱卵率与全暗(黑)组进行对比,发现正常光照组红条鞭腕虾亲虾抱卵率为(95.8±3.6)%,而全暗(黑)组的抱卵率为0,正常光照组亲虾的抱卵率显著高于全暗(黑)组(P0.05),表明适宜的光照强度对红条鞭腕虾亲虾抱卵行为起到促进作用。本研究还对比分析了投喂不同生物饵料对红条鞭腕虾溞状幼体成活率和生长发育周期的影响。结果发现,投喂丰年虫(Artemia nauplii)和蒙古裸腹溞(Moina mongolica Daday)混合组的溞状幼体成活率为(38.3±2.3)%,幼体经过25～29 d全部发育成仔虾;而单一投喂丰年虫组的溞状幼体成活率为(26.8±4.9)%,幼体经过37～41 d全部发育成仔虾;混合组的溞状幼体成活率显著高于单一组(P0.05),且其幼体的生长周期也明显短于单一组,表明投喂丰年虫和蒙古裸腹溞混合饵料比只投喂丰年虫饵料更有利于幼体的存活和发育。此外,本研究还观察和详细描述了红条鞭腕幼体发育过程的形态和结构变化特征,并将它分为溞状幼体1～9期等9个不同时期,幼苗经过9期溞状幼体期后通过蜕皮最终变态为红条鞭腕虾仔虾。本研究对丰富鞭腕虾属虾类的生殖生物学理论和开展其人工繁育研究具有重要的指导意义。     

几种天然饵料对清洁虾亲虾繁殖的影响

采用6种天然饵料喂养清洁虾亲虾,分析其对亲虾性腺发育、繁殖性能以及受精卵质量的影响。性腺发育试验发现,投喂6种不同饵料亲虾性腺发育周期差异显著(P<0.01),最长的为鱼肉组(12.82±1.91)d,最短的为卤虫无节幼体组(11.46±1.76)d;卤虫无节幼体与桡足类组性腺指数、干物质含量及总蛋白质含量随着性腺发育显著增加(P<0.01),增加均在2倍左右。繁殖性能与受精卵质量结果表明,鱼肉组(3 357±621)(粒/g)亲虾相对怀卵量最大,卤虫无节幼体组最小(1 829±213)(粒/g);卤虫无节幼体[(0.110 9±0.016 3)mm3]组亲虾受精卵体积最大,乌贼组最小[(0.096 2±0.014 0)mm3];鱼肉组[(37.33±1.75)μg]的受精卵干重最大,虾肉组最小[(31.00±1.26)μg];桡足类组蛋白质绝对含量[(367.17±25.68)mg/g]在干物质中所占比例(72.34%)最高。此外,6个饵料组中所有亲虾在各抱卵周期内抱卵率与抱卵间期无显著差异。     

Feeding early larval stages of fire shrimp Lysmata debelius (Caridea, Hippolytidae)

An important constraint to the commercial rearing of the marine ornamental shrimp Lysmata debelius is high larval mortality during early stages due to inappropriate procedures of larval collection and not feeding a live prey before one day elapsed after hatching. This incorrect feeding practice is commonly adopted in larval rearing of L. debelius and other ornamental marine shrimps because it is wrongly assumed that reserves of the newly hatched are enough for the first 24 h of life. Present work demonstrates that captive newly hatched L. debelius larvae ingest microalgae within minutes after hatching. When fed solely with Artemia nauplii, they have acceptable survival rates with stocking densities at or below 50 larval L^–1; but when nauplii are combined with microalgae, survival is further improved to zoea 2 as initial mortality is reduced, and higher stocking densities are supported (up to 75 larvae L^–1). The microalgae used were Rhinomonas reticulata, Skeletonema costata and Tetraselmis chuii. Higher survival through metamorphosis to zoea 2 was always observed for groups fed combinations of microalgae including Tetraselmis chuii. It is recommended that, larval collection methods ensure that larvae are fed microalgae within 2–3 h of release.     

Protein and lipid requirement for the growth and reproduction of the peppermint shrimp Lysmata wurdemanni

The effect of dietary protein and lipid level on growth and reproductive efficiency of the pepermint shrimp Lysmata wurdemanni was evaluated over a 90‐day period. The percentage of protein and lipid (%P/L) in the experimental diets varied as follows: 34/7, 34/8, 34/9, 37/7, 37/8, 37/9, 40/7, 40/8 and 40/9, and a commercial diet was used as control (35/7‐Silver Cup^®). Fifteen shrimps per treatment and three replicates were used. The number of moults, survival, and growth, number of ovigerous females as well as protein and carbon content of fertilized eggs were evaluated. The shrimps fed experimental diets 37/7 and 40/9 exhibited a survival of 100%, whilst the survival of shrimp fed diet 40/7 was 73%, without significant differences being observed among the treatment groups. The weight gained (g) by shrimps fed diets 37/9 and 40/8 was significantly greater than the control group. The greatest percentage of ovigerous females was observed in those fed 34/7 and 37/9 diets, and the lowest in the control group. The greatest content of protein/carbon in the eggs was found in females fed the 40/8 diet. The results indicated that a P/L relationship of 34/7% promote efficient growth; however, during the reproductive phase it is necessary to increase the P/L to 40/8% to improve the quality and viability of the eggs.     

Productivity improvement of Lysmata seticaudata (Risso, 1816) larval rearing protocol through modelling

The Monaco shrimp Lysmata seticaudata (Risso, 1816) is a marine ornamental species whose ecology and biology, as well as its larval culture has previously been addressed. The objective of the study was to predict and improve productivity of this species rearing protocol through modelling. The models developed intend to help aquaculturists to maximize survival to postlarva, decrease larval duration and increase synchronism of metamorphosis and newly metamorphosed postlarvae size by manipulating temperature, diet, first feeding period and stocking density.The models developed allow us to conclude that the L. seticaudata rearing protocol productivity can be improved by raising larvae at a density of 40 larvae L^− 1 and fed newly hatched Artemia nauplii since hatching to zoea V, and with Algamac 2000™ enriched Artemia metanauplii from zoea V to metamorphosis to postlarvae.By providing more productive protocols to aquaculturists, destructive practices and wild collection may be reduced.     

Growth, survival, lipid and fatty acid profile of juvenile monaco shrimp Lysmata seticaudata fed on different diets

The present work evaluated the effect of three inexpensive diets (frozen minced mussel and edible cockle (MMC), frozen minced squid (MS) and gilthead seabream feed (GSF)) on growth, survival, sex reversal, lipid classes and fatty acid (FA) profile of juvenile ornamental shrimp Lysmata seticaudata. Shrimp fed GSF displayed the highest survival rate (±SD) (85.2±1.8%) and the highest percentage (±SD) of shrimp changing from male to simultaneous hermaphrodite (SH) phase (25.2±2.2%). All diets promoted growth rates superior to those reported in the wild, with SH shrimp displaying higher total lengths (TL). Shrimp in SH phase fed GSF displayed the highest TL (±SD) (40.6±1.2 mm). Cultured shrimp reflected the lipid content of experimental diets, with shrimp fed GSF displaying the highest triacylglycerols and sterols (ST) contents. The higher rearing density induced by lower mortality rates of shrimp fed GSF, and the high ST levels present in the diet, may explain the higher proportion of shrimp in SH phase. The higher levels of highly unsaturated fatty acids (HUFA) displayed by MS did not promote higher survival or growth rates. The low polyunsaturated fatty acids and HUFA content of MMC was not reflected in cultured shrimp, probably because of a selective retention of these FA.