Reproductive morphology ofEucheumagelatinae (Esper) J. Agardh (Solieriaceae,Gigartinales, rhodophyta)

Eucheuma gelatinae (Esper) J. Agardh has vegetative and reproductive features distinguishing it from other species ofEucheuma. The occurrence of reproductive nemathecia containing carpogonial branches, auxiliary cells and post-fertilization stages including gonimoblast and pericarp initiation, fusion cell formation stages and carposporophyte development are described and ilustrated for the first time for this species. Contribution No. 2380 of the Institute of Oceanology, Chinese Academy of Sciences.     

Extraction of agar from Eucheuma cottonii and Gelidium amansii seaweeds with sonication pretreatment using autoclaving method

The effect of sonication pretreatment condition on Eucheuma cottonii and Gelidium amansii seaweed towards agar extraction wae studied. Four parameters were changed during sonication to investigate the effects on agar yield and quality. These parameters include the time interval, concentration ratio, frequency, and intensity. The highest amount of agar extracted from Eucheuma cottonii species could be obtained from the time interval of 30 min, seaweed weight to solvent volume ratio of 1:20, the frequency of 35 Hz, and the sonication power intensity of 30%. For Gelidium amansii species, the best agar yield also could be obtained from the time interval of 30 min, 1:20 of seaweed weight to water volume ratio, the frequency of 35 Hz, and power intensity of 30%. From the experiment, sonication pretreatment significantly influenced the yield and properties of extracted agar. The sonication with autoclaved seaweed produced agar containing less sulfate content, which is an excellent chemical property for gel electrophoresis applications.The gel strength of sonication with autoclaving for both seaweeds, Eucheuma and Gelidium species was the highest among those by sonication with direct heating, which proved that sonication pretreatment with autoclaving could enhance the physical properties of the agar.     

麒麟菜高活性膳食纤维的提取与功能性试验

采用正交设计法 ,研究了麒麟菜高活性膳食纤维的提取工艺条件 ,筛选出麒麟菜碱处理和漂白的最佳工艺条件 ,提取出麒麟菜高活性膳食纤维 ,并进行人体的功能性试验。结果表明 ,麒麟菜高活性膳食纤维的产率达 32 .4 1% ,颜色较白 ,膳食纤维干基含量 w达 82 .57% ,钙含量 w2 .13% ,磷含量w0 .0 13% ,膨胀力为 2 4 .5m L / g,持水力为 14 50 % ;麒麟菜膳食纤维的功能性优于小麦麸皮膳食纤维 ,对人体便秘具有良好的疗效     

Seasonal Changes of Reproductive Activity and Biochemical Composition of Pen Shell Atrina pectinata Linnaeus,1767 in Bohai Sea,China

Seasonal variations in the biochemical composition and the reproductive cycle of pen shell Atrina pectinata in Bohai Sea were investigated from May 2013 to April 2014. Histological analysis indicated that the reproductive cycle of A. pectinata can be divided into two phases, inactive stage and gametogenesis, which were equally and significantly influenced by seawater temperature and food availability. Gametogenesis began in late autumn(October), and completed in June and July. Spawning took place in August, coinciding with the highest water temperature and the richest phytoplankton. The significantly high glycogen content in adductor muscles sustained throughout the late active and ripeness stages, but plummeted during spawning and inactive stages. The protein content in female gonads exhibited a synchronous increase along with oocyte diameter and lipid content, suggesting that the female gonads could accumulate protein and lipid for vitelline in A. pectinata. Furthermore, the RNA/DNA ratio was found to be a useful index to indicate the level of gonad maturation in both males and females. The findings of the present study provided a foundation for the fishery resource administration and the aquaculture development of this species.     

Histological Characterization of Peppermint Shrimp(Lysmata wurdemanni) Androgenic Gland

The androgenic gland(AG) is an important endocrine gland for male reproductive function in crustaceans. In the present study, we investigated the histological characteristics of the androgenic gland of peppermint shrimp, Lysmata wurdemanni. The peppermint shrimp matures as male first, then some individuals may become euhermaphrodite after several moltings(transitional phase). Euhermaphrodite-phase shrimp acts as male at intermolts. However, it can be fertilized as a female immediately after molting. Considering the male reproductive function acts in its lifespan except for at larval stages, and female reproductive system starts to develop at transitional phase, we hypothesized that AG activity might be reduced to allow and promote vitellogenesis onset in early transitional phase and the following euhermaphrodite phase. So AG cell structure might be different in three phases in L. wurdemanni. The results showed that AG exists in the male in transitional and euhermaphrodite phases. The gland cell clusters surrounding the ejaculatory ducts locate at the roots of the fifth pereopods. The nucleus diameters are similar in the three phases while the nucleus-to-cell ratio is the lowest in euhermaphrodite phase. Our results indicated that for the individuals that will become euhermaphrodite, the cellular structure of AG changes since transitional phase. Male reproductive function which is still available in euhermaphrodite-phase shrimp should be due to the existence of the gland.     

Histological observation of germ cell development and discovery of spermatophores in ovoviviparous black rockfish (Sebastes schlegeli Hilgendorf) in reproductive season

Black rockfish(Sebastes schlegeli) is an important species for culture; however, its reproductive characteristics have not been fully documented. In this study, we investigated the morphology and developmental process of germ cells in this ovoviviparous rockfish in reproductive season(October 2011–November 2012) with histological methods. We found that the gonad of mature fish showed notable seasonal changes in developmental characteristics and morphological structure. The sperm cells matured during a period lasting from October to December, significantly earlier than the oocytes did. A large number of spermatozoa and other cells occurred in testis at different developmental stages. Vitellogenesis in oocytes began in October, and gestation appeared in April next year. Spermatophores were discovered for the first time in Sebastes, which assembled in testis, main sperm duct, oviduct and genital tract, as well as ovarian cavity in October and April. These organs may serve either as production or hiding places for spermatophores and spermatozoa which were stored and transported in form of spermatophores. Testicular degeneration started from the distal part of testis in April, with spermatophores assembled in degenerating testis and waiting for transportation. The copulation probably lasted for a long period, during which the spermatozoa were discharged in batches as spermatophores. These spermatophores were coated with sticky materials secreted from the interstitial areas of testis and the main sperm duct, then transported into ovary.     

Structure and anti-influenza A (H1N1) virus activity of three polysaccharides from Eucheuma denticulatum

Three polysaccharides(EW,EH and EA) were prepared from a red alga Eucheuma denticulatum by sequential extraction with cold water,hot water and sodium hydroxide water solution.Their monosaccharide compositions,relative molecular mass and structural characterization were determined by gas chromatography,high performance 1iquid chromatography,fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy methods.EW was hybrid ι/κ/ν-carrageenan(70 ι/17κ/13ν-carrabiose),EH was mainly ι-carrageenan,and EA was mainly α-1,4-Glucan(88%) but mixed with small amount of ι-carrageenan(12%).The relative molecular mass of EW,EH and EA was 480,580 and 510 kDa,respectively.The anti-influenza A(H1N1) virus activity of these three polysaccharides was evaluated using the Madin-Darby canine kidney cells model.EW showed good anti-H1N1 virus activity,its IC 50 was 276.5 μg mL-1,and the inhibition rate to H1N1 virus was 52% when its concentration was 250 μg mL-1.The IC 50 of ι-carrageenan EH was 366.4 μg mL-1,whereas EA showed lower anti-H1N1 virus activity(IC 50 >430 μg mL-1).Available data obtained give positive evidence that the hybrid carrageenan EW from Eucheuma denticulatum can be used as potential anti-H1N1 virus inhibitor in future.     

A NEW SPECIES OF ZYGNEMOPSIS(ZYGNEMATACEAE)AND ITS REPRODUCTION CYCLES

The morphology and reproduction cycles of a new species,Zygnemopsis hubeiensis Wei are describedand illustrated for a culture homothallic strain collected from Wuhan,Hubei,China.The asexual reproduction is by parthenospores,aplanospores and akinetes.The major events of the sexual cycle,including the genuflection of reproductive cells,gametangial development,gamete formation,gamete fusion,zygote formation,zygospore development,and zygospore germination are observed.     

A new species ofZygnemopsis (zygnemataceae) and its reproduction cycles

The morphology and reproduction cycles of a new species,Zygnemopsis hubeiensis Wei are described and illustrated for a culture homothallic strain collected from Wuhan, Hubei, China. The asexual reproduction is by parthenospores, aplanospores and akinetes. The major events of the sexual cycle, including the genuflection of reproductive cells, gametangial development, gamete formation, gamete fusion, zygote formation, zygospore development, and zygospore germination are observed.     

Reproductive ecology of the seabob shrimp <Emphasis Type="Italic">Xiphopenaeus kroyeri</Emphasis> (Heller, 1862) in a coastal area of Southern Brazil

The predictability of certain environmental factors that affect the life cycle of the seabob shrimp Xiphopenaeus kroyeri (Heller, 1862) was evaluated in a study of its reproductive biology in an area adjacent to Babitonga Bay, State of Santa Catarina, Brazil. Monthly sampling was conducted from July 2010 through June 2011 at depths of 5, 8, 11, 14, and 17 m. 76 004 individuals were obtained, with a pronounced peak in absolute abundance in austral autumn (34 208), coinciding with the annual closed season from March to May. Grain size composition of the sediment showed the closest relationship to the distribution of individuals (multiple linear regression, P <0.05), related to their burying habit. The observed correlations between the abundance of reproductive males (bearing spermatophores) and females with spent gonads (cross-correlation, P <0.05), and between reproductive males and reproductive females (with a 1-month lag) suggest that the peak of reproductive males preceded the peak of female ones. This result agrees with the pattern expected for females, which copulate in post-ecdysis (spent gonads). Spawning seemed to take place at greater depths, as evidenced by the concentration of reproductive females in these areas. The reproductive activities observed here confirm that this species follows a tropical/subtropical reproductive pattern, spawning continuously throughout the year, with the highest peaks in spring and autumn. The data indicate that the juvenile recruitment period observed in August-September resulted from the reproductive output noted in April–May. Additionally, the reproductive period recorded in November led to the juvenile peak observed in March–May.     

DISTRIBUTION AND POPULATION DYNAMICS OF PARACALANUS PARVUS, PARACALANUS CRASSIROSTRIS, AND ACARTIA BIFILOSA (COPEPODA, CALANOIDA) IN THE BOHAI SEA

ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅＢｏｈａｉＳｅａｗａｓｃｈｏｓｅｎａｓｔｈｅｓｉｔｅｏｆｔｈｅｆｉｒｓｔｐｈａｓｅｏｆｔｈｅＣｈｉｎａ ＧＬＯＢＥＣ (ＧｌｏｂａｌＯｃｅａｎＥｃｏｓｙｓｔｅｍＤｙｎａｍｉｃｓ)ｐｒｏｇｒａｍｆｒｏｍ 1 997ｔｏ2 0 0 0 ,ｉｎｗｈｉｃｈｔｈｅｄｙｎａｍｉｃｓｏｆｚｏｏｐｌａｎｋｔｏｎｐｏｐｕｌａｔｉｏｎｓｗａｓｏｎｅｏｆｔｈｅｆｏｕｒｐｒｉｎｃｉｐａｌｆｏｃｉ.Ｓｍａｌｌｃｏｐｅｐｏｄｓｃｏｍｐｒｉｓｅａｎｉｍｐｏｒｔａｎｔｃｏｍｐｏｎｅｎｔｏｆｚｏｏｐｌａｎｋｔｏｎｅｓｐ…     

DISTRIBUTION AND POPULATION DYNAMICS OF PARACALANUS PARVUS,PRACALANUS CRASSIROSTRIS,AND ACARTIA BIFILOSA（COPEPODA,CALANOIDA）IN THE BOHAI SEA

Paracalanus parvus,Paracalanus crassirostris,and Acartia bifilosa are dominant and widely distributed in the Bohai Sea,and comprise an important part of zooplankton in terms of biomass as well as production rate.In order to understand their seasonal distribution and population dynamics,their stage-specific abundance in different months of the year were analyzed based on the never analyzed yet samples collected in 1959.The three species showed clear and remarkable seasonal variation in abundance,which maximized in spring and summer,when they formed high biomass patches or concentrations in the nearshore area.For Paracalanus parvus,two peaks were observed in the annual circle,one in June and the other in September,For Paracalanus crassirostris,one peak occurred in summer and a small one in December.The seasonal pattern of Acartia bifilosa was different in different regions.In Bohai Bay it had a two-peak pattern,with the first large peak occurring in May and the second one in October.In Laizhou Bay,a winter peak in December and January could be observed besides the spring one.The number of generations during the reproductive season for the three species was estimated based on the annual cycle in abundance and ambient temperature.     

Seasonal changes of reproductive activity and biochemical composition of pen shell <Emphasis Type="Italic">Atrina pectinata</Emphasis> Linnaeus, 1767 in Bohai Sea,China

Seasonal variations in the biochemical composition and the reproductive cycle of pen shell Atrina pectinata in Bohai Sea were investigated from May 2013 to April 2014. Histological analysis indicated that the reproductive cycle of A. pectinata can be divided into two phases, inactive stage and gametogenesis, which were equally and significantly influenced by seawater temperature and food availability. Gametogenesis began in late autumn (October), and completed in June and July. Spawning took place in August, coinciding with the highest water temperature and the richest phytoplankton. The significantly high glycogen content in adductor muscles sustained throughout the late active and ripeness stages, but plummeted during spawning and inactive stages. The protein content in female gonads exhibited a synchronous increase along with oocyte diameter and lipid content, suggesting that the female gonads could accumulate protein and lipid for vitelline in A. pectinata. Furthermore, the RNA/DNA ratio was found to be a useful index to indicate the level of gonad maturation in both males and females. The findings of the present study provided a foundation for the fishery resource administration and the aquaculture development of this species.     

Changes during late-stage embryonic development from egg-juvenile to free-living hatchling in Chinese freshwater crab Sinopotamon yangtsekiense (Decapoda, Brachyura, Potamidae)

This study expands on recent reports that direct development in the Chinese potamid freshwater crab Sinopotamon yangtsekiense involves the completion of all brachyuran larval stages (nauplius, zoea, and megalopa) inside the egg case during embryonic development. Detailed studies of embryonic development in this species revealed the presence of an additional larval stage (the egg-juvenile) between the megalopa and the free-living hatchling crab. We described and compared the appendages of the head, thorax, and abdomen of the egg-juvenile with those of the hatchling crab in S. yangtsekiense. Significant differences were found between most of the appendages of these two stages with a soft exoskeleton in the egg-juvenile, no joint articulation, a slimmer appearance, and a lack of setae when compared with the newly emerged free-living hatchling crab. These modifications of the appendages are related to the confinement within the egg case of the egg-megalopa and egg-juvenile during direct development, and the need for the free-living hatchling freshwater crab to move, feed, and respire. In marine crabs, the megalopa gives rise to the first crab stage whereas in freshwater crabs the egg-juvenile follows the megalopa and immediately precedes the free-living first crab stage.     

企鹅珍珠贝生殖细胞的发生

对不同发育阶段的企鹅珍珠贝[Ptedapenguin(Rding)]的性腺结构、生殖细胞结构与分布进行组织学观察,描述精/卵子发生过程中各级精/卵细胞的特征。结果表明:根据雌性生殖细胞形态和卵黄的变化特点,卵子发生经历卵原细胞、无卵黄初级卵母细胞、卵黄形成期卵母细胞及成熟卵子阶段;依据雄性生殖细胞大小和细胞核形态变化,精子发生经历精原细胞、初级精母细胞、次级精母细胞、精子细胞和精子阶段,其中精原细胞存在形态上有差异的A型和B型两种类型。此外还观察到企鹅珍珠贝的性别转化现象。     

中国南沙群岛的双壳纲贝类

报道了中国南沙群岛的双壳纲贝类141种,分隶于5亚纲8目36科77属.从种类的组成中,帘蛤科有18种,蚶科15种,扇贝科11种,鸟蛤科10种,锉蛤科8种,贻贝科、海菊蛤科和樱蛤科各7种,砗磲科6种,其他各科的种类均在5种以内.按种的性质而论,大多数属于和珊瑚礁有密切联系的热带种或亚热带种,区系性质为印度-西太平洋区的印尼-马来亚区.     

Development of suspended conchocelis ofPorphyra haitanensis (Bangiales, Rhodophyta)

This Mar. 1993 to Aug. 1994 study on suspended conchocelis ofPorphyra haitanensis showed that there were three patterns for development of vegetative filaments: filaments to filaments by “budding”; filaments to sporangial branchlets by “budding”, or cell swelling. There were also three patterms for sporangial branchlet development: vegetatively propagating, changing into conchospores, or dying. Each developmental stage had one or more different developmental directions between vegetative filaments and sporangial branchlets. Developments from conchosporangial branchlets to conchospores were sequential and irreversible. Although sporangial branchlets formed at 29°C could give rise to filaments, they could not propagate as healthily under the same conditions as those formed at 25°C did. Probably the crucial period of plant cell differentiation is in the late stage of sporangial branchlets. In line with the developmental directions of different stages, the authors regulated the development of conchocelis to get ideal different developmental stages materials to obtain very developmentally homogeneous stages, including filaments and sporangial branchlets. Contribution No 3283 from the Institute of Oceanology, Chinese Academy of Sciences. Study supported by the Climbing Project B PD-B6-4-2 of the State Science and Technology Commission of China.