Feeding and respiration rates of a planktonic copepod (Calanus sinicus) oversummering in Yellow Sea Cold Bottom Waters

The distribution, feeding and oxygen consumption of Calanus sinicus were studied in August 2001 on a transect across Yellow Sea Cold Bottom Waters (YSCBW) and two additional transects nearby. The distribution of C. sinicus adults and copepodites stage CV appeared to be well correlated with water temperature. They tended to concentrate in the YSCBW (>10,000 ind. m(-2)) to avoid high surface temperature. Gut pigment contents varied from 0.44 to 2.53 ng chlorophyll a equivalents (chl a equiv.) ind.(-1) for adults, and from 0.24 to 2.24 ng chl a equiv. ind.(-1) for CV copepodites. We found no relationship between gut pigment contents and the ambient chl a concentrations. Although the gut evacuation rate constants are consistent with those measured for other copepods, their low gut pigment contents meant an estimated daily herbivorous ingestion of <3% of body carbon in the YSCBW and <10% outside the YSCBW. However, based on estimates of clearance rates, C. sinicus feeds actively whether in the YSCBW or not, so the low ingestion rates probably reflect shortage of food. Oxygen consumption rates of C. sinicus ranged from 0.21 to 0.84 mul O-2 ind.(-1) h(-1), with high rates often associated with high temperature. From the oxygen consumption rates, daily loss of body carbon was estimated to be 4.0-13.7%, which exceeds our estimates of their carbon ingestion rates. C. sinicus was probably not in diapause, either within or outside the YSCBW, but this cold-water layer provides C. sinicus with a refuge to live through the hot, low-food summer.

FEEDING AND VOCAL BEHAVIORS OF BLACK GIBBONS (HYLOBATES-CONCOLOR) IN YUNNAN - A PRELIMINARY-STUDY

Feeding and vocal behaviours of wild black gibbons (Hylobates concolor) were observed from 1987 to 1989 in south-western Yunnan, notably H. concolor jingdongensis at Mt. Wuliang (24-degrees 18-42'N, 100-degrees 30-50'E) in the early spring of 1989. 12 plant species were observed to have been eaten by the gibbons; these included tree species, lianas and epiphytes. Approximately 21 % of feeding time was devoted to eating fruits, 61 % to leaf buds and shoots, 7 % to flowers and 11 % to leaves. The gibbons preferred fruits to leaves even though they commonly ate leaves. In this study, the morning songs (duet and solo), reponsive (territorial) songs, alarm calls and communication calls were recorded. The gibbons sang their morning songs mainly in the early morning, with a single bout lasting more than 10 min on average. The singing of a group would trigger other groups, and all groups in an area tended to sing sequentially. The morning duet song bout was dominated by an adult male. The male emitted booms, aa notes, early multimodulated figures, intermediate multimodulated figures and codas, the latter occurring only in duets following the female's great call. The female uttered great calls and abortive great calls. The subadults or juveniles also took part in the morning songs. Lone males were heard to utter solos which lasted longer than the duets of the pairs.

Distribution, feeding and body condition of four small fish species in the near-shore and central areas of Liangzi Lake, China

Small fish abundance is usually high in heavily vegetated habitats in Yangtze lakes, China. Visual and swimming barriers created by dense macrophytes beds could reduce feeding efficiency and growth of small fishes. We tested the hypothesis that small fishes in habitats with dense macrophytes would show decreased feeding efficiency and reduced growth rates by comparing feeding efficiency (measured as the relative weight of fore-gut contents), total length, and condition factor of four small young-of-the-year fishes collected in the near-shore (heavily vegetated) and central (less vegetated) areas of Liangzi Lake. Feeding efficiency, total length, or condition factor were each significantly reduced in the near-shore area compared with the central area for Ctenogobius giurinus, Pseudorasbora parva and Carassius auratus auratus. This supports our hypothesis that vegetation abundance may mediate feeding efficiency and growth of small fishes. Although Hypseleotris swinhonis did not show significant decreases in feeding efficiency or growth in the near-shore area, there was not any reversed tendency, i.e. increased feeding rate or growth in the near-shore area compared to the central area.

Feeding and egg production of the planktonic copepod Calanus sinicus in spring and autumn in the Yellow Sea, China

Shipboard incubations were conducted in spring (April) and autumn (October/November) 2006 to measure the feeding and egg production rates (EPR) of Calanus sinicus in the Yellow Sea, China. The ingestion rate (2.08-11.46 and 0.26-3.70 mu g C female(-1) day(-1) in spring and autumn, respectively) was positively correlated with microplankton carbon concentrations. In the northern part of the Yellow Sea, feeding on microplankton easily covers the respiratory and production requirements, whereas in the southern part in spring and in the frontal zone in autumn, C. sinicus must ingest alternative food sources. Low ingestion rates, no egg production and the dominance of the fifth copepodite (CV) stage indicated that C. sinicus was in quiescence inside the Yellow Sea Cold Bottom Water (YSCBW) area in autumn. Calanus sinicus ingested ciliates preferentially over other components of the microplankton. The EPR (0.16-12.6 eggs female(-1) day(-1) in spring and 11.4 eggs female(-1) day(-1) at only one station in autumn) increased with ciliate standing stock. Gross growth efficiency (GGE) was 13.4% (3-39%) in spring, which was correlated with the proportion of ciliates in the diet. These results indicate that ciliates have higher nutrient quality than other food items, but the low GGE indicates that the diet of C. sinicus is nutritionally incomplete.

Feeding and growth on bivalve biodeposits by the deposit feeder Stichopus japonicus Selenka (Echinodennata : Holothuroidea) co-cultured in lantern nets

Suspension aquaculture of filter-feeding bivalves has been developing rapidly in coastal waters in the world, especially in China. Previous studies have demonstrated that dense populations of filter-feeding bivalves in shallow water can produce a large amount of faeces and pseudofaeces (biodeposits) that may lead to negative impacts on the benthic environment. To determine whether the deposit feeder Stichopus (Apostichopus) japonicus Selenka can feed on bivalve biodeposits and whether the sea cucumber can be co-cultured with bivalves in suspended lantern nets, three experiments were conducted, two in tanks in the laboratory and one in the field. In a 3-month flow-through experiment, results showed that sea cucumbers grew well with specific growth rate (SGR) reaching 1.38% d(-1), when cultured in the bottom of tanks (10 m(3) water volume) where scallops were cultured in suspension in lantern nets. Moreover, results of another laboratory experiment demonstrated that sea cucumbers could survive well on bivalve biodeposits, with a feeding rate of 1.82 +/- 0.13 g dry biodeposits ind(-1) d(-1), absorption efficiency of organic matter in biodeposits of 17.2% +/- 5.5%, and average SGR of 1.60% d(-1). Our longer-term field experiments in two coastal bays (Sishili Bay and Jiaozhou Bay, northern China) showed that S. japonicus co-cultured with bivalves also grew well at growth rates (0.09-0.31 g wet weight ind(-1) d(-1)) depending on individual size. The results suggest that bivalve lantern nets can provide a good habitat for sea cucumbers; and the co-culture of bivalve molluscs with sea cucumbers may provide an additional valuable crop with no additional inputs. (c) 2006 Elsevier B.V. All rights reserved.

Compensatory growth and food consumption in gibel carp, Carassius auratus gibelio, and Chinese longsnout catfish, Leiocassis longirostris, experiencing cycles of feed deprivation and re-feeding

The compensatory responses of juvenile gibel carp and Chinese longsnout catfish to four cycles of 1 part of a study designed to determine feeding regimes that would maximise growth rates. Both species showed compensatory growth in the re-feeding periods. The compensation was not sufficient for the deprived fish to match the growth trajectories of controls fed to satiation daily. The compensatory growth response was more clearly defined in the later cycles. The deprived fish showed hyperphagia during the 2-week periods of re-feeding and the hyperphagic response was clearer in the later cycles. The hyperphagia tended to persist for both weeks of the re-feeding period. The gibel carp showed no difference in gross growth efficiency between deprived and control fish. In the catfish, the gross growth efficiency of the deprived fish was marginally higher than that of control fish, but the efficiency varied erratically from week to week. Over the experiment, the deprived fish achieved growth rates 75-80% of those shown by control fish, although fed at a frequency of 66%. There was no evidence of growth over-compensation with the deprivation-re-feeding protocol used in this study. (C) 2004 Elsevier B.V. All rights reserved.

Effect of feeding strategy and carbohydrate source on carbohydrate utilization by white sturgeon (Acipenser transmontanus) and hybrid tilapia (Oreochromis niloticus X O-aureus)

Two 8-week growth trials were conducted to determine the effect of continuous (CF) versus 2 meals day(-1) (MF) feeding and 30% starch versus 30% glucose diets on the carbohydrate utilization of 9.0-g white sturgeon and 0.56-g hybrid tilapia. The two trials were conducted under similar conditions except that sturgeon were kept at 18.5 degrees C in a flow-through system and tilapia were kept at 26 degrees C in a recirculating system. Significantly (P less than or equal to 0.05) higher specific growth rate (SGR), feed efficiency (FE), protein efficiency ratio (PER), body lipid content and liver glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6PGDH) activities were observed in the CF than MF sturgeon. Only SGR, FE and PER were higher in sturgeon fed the starch than the glucose diets. Only higher liver G6PDH and malic enzyme (ME) activities were observed in the CF than MF tilapia but higher SGR, FE, PER and liver G6PDH, 6PGDH and ME activities were observed in tilapia fed the starch diet than those fed the glucose diet. This suggested that carbohydrate utilization by sturgeon was more affected by feeding strategy whereas tilapia was more affected by carbohydrate source. Furthermore, white sturgeon can utilize carbohydrates better than hybrid tilapia regardless of feeding strategy and carbohydrate source.

Observations on the nocturnal activity and feeding behavior of Anguilla japonica glass eels under laboratory conditions

Glass eels of the temperate anguillid species, Anguilla japonica, clearly showed a nocturnal activity rhythm under laboratory conditions. Light-dark cycle was a determinant factor affecting their photonegative behavior, nocturnal locomotor activity, and feeding behavior. Under natural light conditions, glass eels remained in shelters with little daytime feeding, but came out to forage during darkness. They moved and foraged actively in the following dark, and then their activity gradually declined possibly because of food satiation. They finally buried in the sand or stayed in tubes immediately after the lights came on. Under constant light, glass eels often came out of the shelters to forage in the lights but spent little time moving outside the shelters (e.g. swimming or crawling on the sand). Glass eels took shelter to avoid light and preferred tubes to sand for shelter possibly because tubes were much easier for them to take refuge in than sand. Feeding and locomotor activities of the glass eels were nocturnal and well synchronized. They appeared to depend on olfaction rather than vision to detect and capture prey in darkness. Feeding was the driving force for glass eels to come out of sand under constant light. However, in the dark, some glass eels swam or crept actively on sand even when they were fully fed. The lunar cycles of activity rhythms of glass eels that have been observed in some estuarine areas were not detected under these laboratory conditions.

Generation of long, laminar plasma jets at atmospheric pressure and effects of flow turbulence

Long, laminar plasma jets at atmospheric pressure of pure argon and a mixture of argon and nitrogen with jet length up to 45 fi,Hes its diameter could be generated with a DC are torch by! restricting the movement of arc root in the torch channel. Effects of torch structure, gas feeding, and characteristics of power supply on the length of plasma jets were experimentally examined. Plasma jets of considerable length and excellent stability could be obtained by regulating the generating parameters, including are channel geometry gas flow I ate, and feeding methods, etc. Influence of flow turbulence at the torch,nozzle exit on the temperature distribution of plasma jets was numerically simulated. The analysis indicated that laminar flow plasma with very low initial turbulent kinetic energy will produce a long jet, with low axial temperature gradient. This kind of long laminar plasma jet could greatly improve the controllability for materials processing, compared with a short turbulent are let.

Characterization of Sarcocystis species in domestic animals using a PCR-RFLP analysis of variation in the 18S rRNA gene: a cost-effective and simple technique for routine species identification

Thirteen restriction endonucleases were used to investigate nucleotide sequence variation in the 18S rRNA DNA of 88 individuals from ten Sarcocystis taxa collected as cysts from their intermediate hosts, swine, cattle and water buffalo. A DNA sequence of

Altitudinal Ranging of Black-Crested Gibbons at Mt. Wuliang, Yunnan: Effects of Food Distribution, Temperature and Human Disturbance

We studied the altitudinal ranging of one habituated group of black-crested gibbons (Nomascus concolor) at Dazhaizi, Mt. Wuliang, Yunnan, China, between March 2005 and April 2006. The group ranged from 1,900 to 2,680 m above sea level. Food distribution was the driving force behind the altitudinal ranging patterns of the study group. They spent 83.2% of their time ranging between 2,100 and 2,400 m, where 75.8% of important food patches occurred. They avoided using the area above 2,500 m despite a lack of human disturbance there, apparently because there were few food resources. Temperature had a limited effect on seasonal altitudinal ranging but probably explained the diel altitudinal ranging of the group, which tended to use the lower zone in the cold morning and the higher zone in the warm afternoon. Grazing goats, the main disturbance, were limited to below 2,100 m, which was defined as the high-disturbance area (HDA). Gibbons spent less time in the HDA and, when ranging there, spent more time feeding and travelling and less time resting and singing. Human activities directly influenced gibbon behaviour, might cause forest degradation and create dispersal barriers between populations. Copyright (C) 2010 S. Karger AG, Basel

NATURAL FOODS AND THEIR ECOLOGICAL IMPLICATIONS FOR MACACA-THIBETANA AT MOUNT EMEI, CHINA

Natural food plants of partly provisioned groups of Macaca thibetana included about 196 species belonging to 135 genera and 72 families. The macaques consumed mainly bamboo shoots and fruits for about 2 months in autumn, whereas they relied on active or passive provisions from visitors, a variety of structural parts of plants and a small amount of invertebrates in late spring and summer and ate mainly mature leaves and bark for the rest of the year. About half of the species eaten came from the dense herb and shrub layers. This forest-dwelling species shows a distinctive feeding and foraging pattern in comparison with other macaques, explaining why M. thibetana has the largest body weight of all macaques.

Influence of leaf tissue structure on host feeding selection by pea leaf miner Liriomyza huidobrensis (Diptera : Agromyzidae)

Host feeding selection by the female pea leafminer, Liriomyza huidobrensis, on 47 species of plants was studied. The leaves were sectioned by microtome, and 15 characteristics of the leaf tissue structure were measured under a microscope. Correlation analysis between host feeding selection and leaf tissue structure indicated that the preference of host feeding selection was positively correlated with the percentage of moisture content of leaves and negatively with thickness of the epidermis wall, and densities of the palisade and spongy tissues of leaves. Leaf tissue structure was influential in feeding and probing behavior of female L. huidobrensis. So, thickness of epidermis wall, densities of the palisade and spongy tissues can act as a physical barrier to female oviposition. Furthermore, higher densities of palisade and spongy tissues can be considered a resistant trait which affects mining of leaf miner larvae as well. As a result, plants with lower leaf moisture content may not be suitable for the development of L. huidobrensis.

Effects of body size and water temperature on food consumption and growth in the sea cucumber Apostichopus japonicus (Selenka) with special reference to aestivation

To investigate the effects of body size and water temperature on feeding and growth in the sea cucumber Apostichopus japonicus (Selenka), the maximum rate of food consumption in terms of energy (C-maxe; J day(-1)) and the specific growth rate in terms of energy (SGRe; % day(-1)) in animals of three body sizes (mean +/- SE) - large (134.0 +/- 3.5 g), medium (73.6 +/- 2.2 g) and small (36.5 +/- 1.2 g) - were determined at water temperatures of 10, 15, 20, 25 and 30 degrees C. Maximum rate of food consumption in terms of energy increased and SGRe decreased with increasing body weight at 10, 15 and 20 degrees C. This trend, however, was not apparent at 25 and 30 degrees C, which could be influenced by aestivation. High water temperatures (above 20 degrees C) were disadvantageous to feeding and growth of this animal; SGRe of A. japonicus during aestivation was negative. The optimum temperatures for food consumption and for growth were similar and were between 14 and 15 degrees C, and body size seemed to have a slight effect on the optimal temperature for food consumption or growth. Because aestivation of A. japonicus was temperature dependent, the present paper also documented the threshold temperatures to aestivation as indicated by feeding cessation. Deduced from daily food consumption of individuals, the threshold temperature to aestivation for large and medium animals (73.3-139.3 g) was 24.5-25.5 degrees C, while that for small animals (28.9-40.7 g) was between 25.5 and 30.5 degrees C. These values are higher than previous reports; differences in sign of aestivation, experimental condition and dwelling district of test animals could be the reasons.

Growth, pigmentation and activity of juvenile Japanese eels in relation to temperature and fish size

The growth and activity of juvenile Japanese eels Anguilla Japonica in different pigmentation stages from the glass eel to the elver stage were studied in the laboratory at 15, 20 and 25degrees C. The growth and activity of the eels were significantly influenced by both temperature and fish size. Growth rate generally declined with increasing fish size, and fish were least active and experienced a low growth during the pigmenting stage at all temperatures. They were nocturnal and spent significantly more time moving (swimming, feeding and moving over the substratum) at 20 and 25degrees C than at 15degrees C at night within each pigmentation stage. Accordingly, they grew significantly Faster at 20 and 25degrees C than at 15degrees C throughout the study. The development of pigmentation appeared to be dependant on water temperature but not on fish size. This study suggested that the growth and activity of juvenile Japanese eels were positively correlated, because fish were least active and grew slowest at low temperature (15degrees C) or during the pigmenting stage at all temperatures. (C) 2003 The Fisheries Society of the British Isles.