东、黄海鱼是鱼集群分布模式的研究

根据７个冬季变水层拖网瞄准捕捞越冬鱼是鱼平均小时产量统计和探鱼仪鱼群映象纪录资料，研究了鱼是鱼集群分布模式和集群密度。鱼是鱼集群分为表层型、中层型和近底层型３种分布模式。１４种典型集群映象有捕捞生产价值。３种模式的鱼是鱼集群密度是：中层型高于近底层型，近底层型高于表层型。使用５２０目×６００毫米变水层拖网瞄准捕捞中层型集群鱼是鱼平均小时产量５．０～１４．０吨、近底层型３．６～４．５吨和表层型２．３～３．０吨     

珍味贝丝的研制报告

本试验利用扇贝加工时大量废弃的裙边,制作调味焙烤品珍味贝丝,经1％冰醋酸软化处理15s,150℃焙烤6min,较好地解决了艮韧问题,并对工艺路线和主要工艺参数进行了选择。制品档次较高,保质期达6个月以上。     

Decadal variation in the trans-Pacific migration of northern bluefin tuna (Thunnus thynnus) coherent with climate-induced change in prey abundance

Northern bluefin tuna, Thunnus thynnus, apparently spawn only in the western Pacific and a portion of the juveniles migrate to the eastern Pacific. During the past decade, catches of northern bluefin in the eastern Pacific have declined. One possible cause for this decline, proposed by bluefin stock assessment studies, is a decline in the proportion of bluefin that migrate out of the western Pacific. This hypothesis is examined with several indices of the relative abundance of bluefin tuna in the western and eastern Pacific. These indices suggest a decline in the proportion of bluefin migrating to the eastern Pacific since 1977. This period of reduced bluefin migration coincides with a period when a prey of bluefin, Japanese sardine, Sardinops melanosticta, were abundant off Japan. It is hypothesized that in years when sardines are abundant off Japan, a higher proportion of bluefin stay in the western Pacific compared with years when sardines are scarce. Currently, the adun-dance of sardines off Japan is declining. If this decline continues, this hypothesis predicts an increase in bluefin migrating north of Hawaii and into the eastern Pacific.     

Complete mitochondrial DNA sequence of the Japanese anchovy Engraulis japonicus

ABSTRACT: The complete nucleotide sequence of the mitochondrial genome for the Japanese anchovy Engraulis japonicus (Teleostei: Clupeiformes) was determined. The entire genome was purified by gene amplification using the long polymerase chain reaction (PCR) technique, and products were subsequently used as templates for PCR with 56 fish-versatile primers that amplify contiguous, overlapping segments of the entire genome. Direct sequencing of the PCR products demonstrated that the genome (16 675 base pairs [bp]) contained the same 37 mitochondrial genes (two ribosomal RNA, 22 transfer RNA and 13 protein-coding genes) as those found in other vertebrates, with the gene order being identical to that in typical vertebrates. A major non-coding region between the tRNA^Pro and tRNA^Phe genes (1024 bp) was considered to be the control (D-loop) region, as it has several conservative blocks characteristic to this region.     

Distribution of three GnRHs in the brain and pituitary of the wild Japanese flounder Paralichthys olivaceus

ABSTRACT:   Wild adult maturing and immature female Japanese flounder Paralichthys olivaceus were collected in June 2004 and January 2005, respectively, to clarify a possible role of gonadotropin-releasing hormones (GnRHs) in reproduction. Levels of salmon GnRH (sGnRH), chicken GnRH-II (cGnRH-II) and sea bream GnRH (sbGnRH) in the brain and pituitary were examined by time-resolved fluoroimmunoassay. Three forms of GnRHs were detected in the discrete brain at various levels. In the pituitary of both maturing and immature fish, sbGnRH was abundant together with a pronounced amount of sGnRH, whereas cGnRH-II was almost below the detectable limit. In maturing fish, levels of sbGnRH were high in the telencephalon, hypothalamus and pituitary, while levels of sbGnRH of immature fish were very low in these regions. These results indicate that sbGnRH is mainly responsible for gonadotropin secretion, and that sbGnRH in the anterior part of the brain is associated with gonadal maturation in the Japanese flounder.