Longevity of marine cystophorous cercariae in the environment

Experiments were conducted on the duration of life in sea water of three species of cystophorous cercariae from the Barents sea. The expenditure of reserve nutritive substances (glycogene) in the process of the vital activity of cercariae was followed. The life duration of cystophorous cercariae is considerably longer than that cited in literature for other groups of cercariae that is associated with their morphological and biological peculiarities.     

Data on distribution and biology of poachers agonidae from the northwestern part of the Bering Sea

On the basis of materials of 1996–2003, specific features of spatial and seasonal distribution of four species of Agonidae (Percis japonica, Sarritor frenatus, S. leptorhynchus, and Aspidophoroides bartoni) in the northwestern part of the Bering Sea are considered. In this area of the studied species, P. japonica is found in catches most frequently (occurrence reaches 81.8%); the rarest here is S. leptorhynchus (0.7–7.0%). P. japonica begins to spawn in mid-July, and S. frenatus terminates spawning in the second ten-day period in August. Mass (50%) sexual maturation of female P. japonica occurs at a length of 29 cm, and of males, at 23 cm; in S. frenatus, at 24–25 and 23 cm, respectively. The individual absolute fecundity of P. japonica averages 6361 eggs, and oocyte diameter, 2.9 mm; of S. frenatus, 2848 eggs and 1.53 mm, respectively. The bulk of feeding of P. japonica is formed by polychaetes; next in importance are amphipods and caprellids. The bulk of feeding of S. frenatus is formed by amphipods; polychaetes, isopods, and euphausiids (in decreasing order) are also important in the feeding of this species.     

Thermal biology of sea snakes and sea kraits1

Temperature probably had no direct effect on the evolution of sea kraits within their center of origin, a geologically stable thermal zone straddling the equator, but may have indirectly affected expansions and contractions in distributions beyond that zone through global fluctuations that caused alternation of higher and lower sea levels. The northern limit of the Laticauda colubrina complex seems to be the 20°C isotherm; in the south, the range does not reach that isotherm because there is no land (also a habitat requirement of sea kraits) within the zone of suitable temperature. The relationship of temperature to the pattern of geographic variation in morphology supports either the hypothesis of peripheral convergence or the developmental hypothesis but does not distinguish between them. Quadratic surfaces relating cumulative scores for coloration and morphological characters to global position showed a strong latitudinal component and an even stronger longitudinal one in which the direction of the latitudinal effect was reversed between east and west. A multivariate analysis revealed that while morphological characters vary significantly by location and climate when tested separately, when the influence of location on morphology is taken into account, no residual relationship between climate and morphology remains. Most marine snakes have mean upper temperature tolerances between 39°C and 40°C and operate at temperatures much nearer their upper thermal limits than their lower limits but still avoid deleterious extremes by diving from excessively hot water to deeper, cooler strata, and by surfacing when water is cold. At the surface in still water in sunlight, Pelamis can maintain its body temperature slightly above that of the water, but whether this is significant in nature is questionable. As temperature falls below 18-20°C, survival time is progressively reduced, accompanied by the successive occurrence of cessation of feeding, cessation of swimming, and failure to orient. Acclimation does not seem to be in this species' repertoire. In the water column, marine snakes track water temperature; on land, sea kraits can thermoregulate by basking, selecting favorable locations, and by kleptothermy. Laticauda colubrina adjusts its reproductive cycle geographically in ways that avoid breeding in the coldest months. Mean voluntary diving time is not temperature-dependent within the normal range of temperatures experienced by marine snakes in the field, but is reduced in water colder than 20°C. On land, much as while diving in the sea, sea kraits maintain long periods of apnea; intervals between breaths are inversely related to temperature.     

长木蜂的形态和生物学观察

长木蜂Xylocopa tranquebarorum(Swederus)属于多访花性昆虫。本文报道了长木蜂的形态特征、生活史及幼虫和成虫的行为等生物学特性。该蜂在南京地区1年发生1代,以成虫在巢室内越冬。翌年的3月下旬成虫开始外出活动,主要是筑巢、采集粉蜜、酿贮蜂粮和产卵。6月中旬至7月下旬新一代成虫羽化,新羽化的成虫群集在蜜源植物青桐树上补充营养,并在青桐的附近空中婚飞、交配。室内观察长木蜂的卵期9～11d,平均(9.97±0.76)d;幼虫期19～22d,平均(20.30±1.18)d,预蛹期8～9d,平均(8.53±0.51)d,蛹期19～21d,平均(19.67±0.66)d。雌雄比为2.17∶1。雌蜂酿制蜂粮的盛期在5月上旬,采集蜂粮的最佳时期在5月上中旬。该蜂的卵产在块状的蜂粮上,卵长10.06～13.34mm,腊肠形或香蕉形,略弯曲,两端钝圆,头部略窄与尾部,尾部最宽,重(0.0438±0.0122)g。     

黑广肩步甲形态特征及其生物学特性

记述了黑广肩步甲CalosomamaximocicziMorawitz各虫态的形态特征、生物学特性。在山东栖霞地区,该虫1年发生1代,以成虫在土壤中越冬。成虫在5月中旬至9月末发生,8月产卵。卵期平均为5d;幼虫共3龄,历期分别为5～6d,4～5d,5～6d;预蛹期约为25d;蛹期为24～27d。成、幼虫以多种鳞翅目幼虫为食。     

壮铗普瘿蚊的形态学与生物学习性

壮铗普瘿蚊是厦门市区出现的一种危害芒果树叶片的新害虫,现已扩散到厦门周边地区。文中对其各虫态的形态特征作了详细的描述,并对其生活史、习性进行了研究。该虫在厦门1 a发生5代,一个世代历期44-52 d。成虫在芒果嫩叶背面产卵,经2-4 d孵出幼虫后侵入叶肉并逐渐发育形成疱状突起的虫瘿,以幼虫和蛹在叶片上的虫瘿内越冬。     

绿步甲的形态特征及其生物学特性

记述绿步甲Carabus(Coptolabrus)smaragdinus Fischervon Waldheim各虫态的形态特征及其生物学特性。在山东嘉祥,该虫1年发生2代,以成虫在土壤中越冬。成虫在4月至10月活动,分别与7月上旬、9月中旬产卵。卵期平均为8d;幼虫共2龄,历期分别为4d,13～15d;预蛹期约为15d;蛹期为7～8d。成、幼虫以蜗牛和多种鳞翅目昆虫为食。     

Morphology,biology and pesticide tolerance ofChelotogenes ornatus [Acari: Cheyletidae]

BioControl - This paper reports on the morphology, biology and pesticide tolerance ofCheletogenes ornatus (Canestrini &;amp; Fanzago), the most common predator ofPinnaspis aspidistrae (Signoret)...     

Morphology and biology of 2 ecotypes of Chaetogaster lymnaei, Baer, 1827]

Chaetogaster lymnaei (Oligochaeta, Naididae) has two life forms one of which is a commensal of pulmonae mollusks and the other--an endoparasite of Radix ovata Kidney. On the basis of statistical analysis of the second body segment chaetae morphological differences of the two races are considered. Their geographical distribution and biological peculiarities are discussed. The races of Gh. lymnaei represent two divergating sympatrical ecotypes rather than biological species as it was thought before.     

Respiration and motor activity of cercariae of three trematode species from the intertidal mollusc Littorina littorea L (Gastropoda) from the White sea

The age dynamics in oxygen consumption of the cercariae Himasthla elongata, Cryptocotyle lingua and Cercaria parvicaudata (Renicola sp.) was studied using modified Winkler's method. It was detected that under stable temperature and water salinity conditions the rate of oxygen uptake depends directly on cercariae size. The highest intensity of energetic metabolism was recorded in the first few hours of cercariae life when their movement activity was maximal. The following reduction of oxygen consumption passed unequally in three cercariae species studied. Large, long-lived H. elongata cercariae after relatively short period of active swimming turn to crawling on the bottom. The rate of oxygen uptake in such cercariae was two times less than in free-swimming ones and remained approximately invariable up to the cercariae death. The smaller sized, short-lived Renicola sp. cercariae swim actively in the water and during this time the level of their energetic metabolism remains more or less stable. It decreased drastically after cercariae sinking to the bottom, after that they perished very soon. Also relatively small C. lingua cercariae alternate the active and passive phases of swimming. Thanks to that they consume the energetic resources economically and prolong their longevity. During free-swimming period the rate of oxygen uptake of C. lingua cercariae remains more or less stable. As in the case of Renicola sp. cercariae, it decreased drastically after the cercariae sinking to the bottom. Apparently such cercariae lose their ability to infect the second intermediate host (fish).     

Isolation of iodine-protein components from sea algae]

The isolation of iodorganic compounds from the Black Sea red alga Phyllophora nervosa and its by-products obtained from industrial treatment was investigated. The algal biomass was pressed to remove alkali, subjected to 5-10 min treatment with 11-12% sodium hydrate, and drying at 125-130 degrees C and washed to yield 95% iodine and over 80% proteins. Iodine was found to be bound with protein of Phyllophora. Properties of the isolated iodine-peptide fractions were studied.     

Notes on the biology of sea ice in the Arctic and Antarctic

The sea ice which covers large areas of the polar regions plays a major role in the marine ecosystem of both the Arctic and Southern Oceans. Not only do warmblooded animals depend on sea ice as a platform, but the sympagic organisms living internally within the sea ice or at the interfaces ice/snow and ice/water provide a substantial part of the total primary production of the ice covered regions. In addition sea ice organisms are an important food source for a variety of pelagic animals and may initiate phytoplankton spring blooms after ice melt by seeding effects.Sea ice organisms often are enriched by some orders of magnitude if the same volume of melted ice is compared to that of the underlying water column. Three hypotheses try to explain this discrepancy and are discussed. Investigations on the nutrient chemistry within the sea ice system and in-situ observations still are rare. Intense growth of sympagic organisms can result in nutrient deficiencies, at least in selected habitats. Advances in endoscopie methods may lead to a better understanding of the life within the sea ice.Paper presented at the Symposium on Polar regions: the challenge for biological and ecological research organised by the Swiss Committee for Polar Research, Basel on 2 October 1992     

Observations of the biology and parasites of postsmolt Atlantic salmon, Salmo salar, from the Norwegian sea

The main food items of postsmolt Atlantic salmon caught in the Norwegian sea during summer 1991 were Parathemisto spp. and herring ( Chipca harengus ). The most prevalent parasite species were Chloromyxion sp., Apatemon sp., H. adunction, A simplex and I. salmonis .     

Morphological observations of Echinochasmus japonicus cercariae and the in vitro maintenance of its life cycle from cercariae to adults

The cercaria morphology of Echinochasmus japonicus was investigated using light and scanning electron microscopy. Cercariae, liberated from naturally infected snails (Parafossarulus manchouricus), had ovoid bodies and diminutive tails. The cercaria tegument was covered with minute spines. Four type II sensory papillae were observed on the dorsal side of the oral sucker, and type I papillae were distributed on the dorsal tegument surfaces. When cercariae were kept in the same bath as the freshwater fish, Pseudorasbora parva, which were free from trematode infections, parasites encysted only in the gills of fishes at day 4 postinfection (PI). The outermost metacercaria wall was fully formed in host tissues at day 7 PI. Adult worms were recovered from the intestines of rats, chicks, and ducks 28 days after experimental exposure to metacercariae. The head crown of the adult was armed with 24 collar spines, which were interrupted dorsal to the oral sucker, and the species was identified as E. japonicus.