Insecticidal activity of residual Bt protein at the second trophic level

Since the first commercial release of transgenic crop expressing genes from Bacillus thuringiensis (Bt), there have been concerns about its potential impact on the environment. Research has focused on the ecological effects from second exposure to Bt prot…     

生物技术在海洋鱼类苗种培育中的应用:现状与前景

围绕海洋鱼类苗种培育过程中饵料和病害这两个关键问题,就基因克隆、重组蛋白、DNA疫苗、抗菌肽和转基因技术等生物技术和产品在鱼类中的研究现状和前景进行讨论和分析,提出应针对鱼苗的营养需求和消化吸收的生理特点,有效利用基因工程产品;同时,要研究和采用新的病害控制技术,提高苗种成活率.苗种培育是海洋鱼类养殖业发展的基础,在苗种培育中加强生物技术的应用,将大力推动海洋鱼类养殖业的健康可持续发展.     

自然产卵的赤点石斑鱼胚胎及仔鱼形态发育研究

介绍赤点石斑鱼（Epinephelus akaara)人工种苗繁殖生产中,以自然产出的受精卵为材料,进行孵化、培育,连续观察该种鱼的胚胎发育过程及仔鱼的形态,并对其作的详细描述。     

Complete larval development of the rare porcellanid crab,Novorostrum decorocrus Osawa, 1998 (Crustacea: Decapoda: Anomura: Porcellanidae), reared under laboratory conditions

The complete larval development of Novorostrum decorocrus Osawa, , is described and illustrated on the basis of laboratory‐reared material. Two zoeal stages and one megalop stage were recorded. Zoeas of N. decorocrus closely resemble those of N. indicum in the appendage characters, including the endopod of the maxillule with only a single stout seta on the distal margin. This character is unique to Novorostrum zoeas. However, N. decorocrus is distinguished from N. indicum by the setation on the endopod of the maxilla and the basis of the second maxilliped in both zoeal stages. The megalops of N. decorocrus are characterized by having a strongly elongate carapace, and differs considerably from the adults in the structure of the carapace, rostrum and third thoracic sternite, and in the armature of the pereiopods. The larval duration of N. decorocrus suggests that this rare porcellanid is more widely distributed than currently known.     

Interspecific differences in early life‐history traits in crested newts (Triturus cristatus superspecies,Caudata, Salamandridae) from the Balkan Peninsula

We studied intraspecific and interspecific variations of early life‐history traits for four crested newt species with different habitat preferences. Although we found considerable variation in size and growth rate between offspring of conspecific females, the species effect appeared to be much more pronounced. The crested newt species we examined differed in egg size, size of larvae at hatching and growth rate. Triturus dobrogicus appeared to be the outlier species among these species, and showed (1) the smallest egg size, (2) the smallest larval size at hatching and (3) the longest larval period, resulting in the largest metamorphosed juveniles.     

Morphology and biology of a new Rhynchospio species (Annelida: Spionidae) from the South China Sea,Vietnam, with the review of Rhynchospio taxa

Adults of a new spionid polychaete, Rhynchospio nhatrangi, inhabit sandy tubes on muddy sand intertidal flats in an estuary of Nha Trang Bay, southern Vietnam. The worms are up to 8 mm long and 0.5 mm wide for 55 chaetigers. They are unique among spionids in the changes in the arrangement of hooks during ontogenesis: first development of tridentate hooks in neuropodia from chaetiger 10, later loss of hooks in chaetiger 10, and replacement of tridentate hooks by heavy unidentate hooks in neuropodia of chaetigers 11–14. Adults are simultaneous hermaphrodites having sperm in chaetigers 11–14 and oocytes from chaetiger 15 to 23–33. Spermatozoa are introsperm, about 300 µm long. Oocytes are about 120 µm in diameter, with a thin and smooth envelope. Fertilization and early larval development occur in a hatchery formed by elongated dorsal capillaries on the posterior chaetigers. Larvae escape from the hatchery probably when they have developed four chaetigers and then continue development in seawater, feeding on the plankton. When larvae have grown to 14–15 chaetigers, they likely undergo gradual metamorphosis and settle on the bottom. Metameric nuchal organs, glandular pouches in neuropodia, metanephridial segmental organs, hermaphroditism, sperm, and early larval morphology are described here for the first time for Rhynchospio species. An identification key is provided to eight currently recognized Rhynchospio species.     

Bionomics,behaviour and immature stages of Pelecotoma fennica (Paykull) (Coleoptera: Rhipiphoridae)

Ptilinus fuscus (Anobiidae) was confirmed as the host species of Pelecotoma fennica (Rhipiphoridae, Pelecotominae). Females of Pelecotoma oviposit into the wood infested by the host larvae. First-instar larvae are elongate, unsclerotized, very different from the triungulinid larvae known in other rhipiphorids. They search actively for the host larvae in the wood; no phoresy is involved in the life cycle. The first-instar larvae temporarily paralyse the host larva and enter its body, overwintering (some perhaps more than once) as an endoparasite. In the spring of the year of emergence, the endoparasite engorges enormously (without moulting) and develops a special sclerotized caudal structure which is then used for perforation of the host's integument. The larva undergoes a further four ectoparasitic instars. The fifth (i.e. fourth ectoparasitic) instar differs considerably from the preceding three, and is capable of boring through the wood to prepare the emergence gallery for the adult. Pupation occurs in the wood. The rate of parasitization may locally far exceed 50%. Superparasitization by the first-instar larvae is possible, but usually only 1 larva survives to the ectoparasitic stage. Larval morphology of Pelecotoma is described and illustrated. Additional data on bionomics and larval morphology are also presented for the genus Metoecus (Rhipiphorinae). Comparing the biology and larval morphology of Pelecotoma with other Rhipiphoridae, it is assumed that ancestral rhipiphorids may have been xylophilous Tenebrionoidea with predaceous or omnivorous larvae, and that the ‘triungulinid’ larvae and phoretic habits may not belong to the groundplan of the family Rhipiphoridae. The widespread opinion considering Rhipiphoridae closely related to the family Mordellidae is questioned.