Jakov Dulčić, Pero Tutman and Branko Dragičević
Ivo S. Orellana Salazar and Raúl Cruz
The two spiny lobster fisheries targeting Panulirus argus (Latreille, 1804) and Panulirus laevicauda (Latreille, 1817) have made an important marine resource in Northeast Brazil since 1955. The Von Bertalanffy age and growth parameters of the spiny lobster started being studied in 1960 and the last assessment was performed over 20 years ago. The objective of this review is to analyse the type of input data and the methods historically used to assess age and growth of the spiny lobster stock in Northeast Brazil.
Our study reviews and updates the research on the subject and proposes relative values for the Von Bertalanffy growth parameters for P. argus and P. laevicauda as provisional reference. We recommend further age and growth research on spiny lobsters to create a new and updated growth function for commercial lobsters in Northeast Brazil.
Patricio De los Rios, Angel Contreras and Eriko Carreño
Mohammad S. Hossain, Japar S. Bujang, Abu Hena M. Kamal, Muta H. Zakaria and Aidy M. Muslim
The behavioural response of the mud lobster, Thalassina anomala Herbst, 1804, to different trapping devices (TD), was studied in the mangrove areas of Sibuti, Sarawak, East Malaysia. Nine different TDs were deployed in this study. Observations revealed that there were no differences in response, neither due to the various types of mound, or as a result of the different TDs: rather, the lobsters either avoided, or obstructed those TDs. Detailed observations revealed that the mud lobsters showed skilled avoidance by either moving freshly dug, moist mud into the TD-types made of bamboo and plastic, or moved the fishing net out of the burrow when it was obstructed by such a type of TD. The damaged parts of the mound caused by deployment of the TD were successfully reconstructed or rebuilt by the mud lobster, using moist mud from the bottom of their tunnel. There was no particular period determined, i.e., neither by day nor at night, when the mud lobsters repaired or rebuilt their opened or otherwise disturbed burrows.
Xiaodong Jiang, Xugan Wu, Haining Wang, Yuhong Yang and Yongxu Cheng
Although morphology is always used to distinguish wild Chinese mitten crab (Eriocheir sinensis) populations, whether morphology could be used to identify the pond-reared offspring of wild E. sinensis populations has remained unclear. This study was undertaken to examine the morphological difference of wild E. sinensis (G0) from the Yangtze River (YR), Huang River (HR) and Liao River (LR) as well as their pond-reared offspring (G1). The results showed that: (1) The amount of significantly different parameters of three G1 populations was evidently less than that of three G0 populations; (2) G0 and G1 individuals of each population were clearly separated by principal component analysis, furthermore, three G0 populations were clearly separated while three G1 populations were not well distinguished from each other; (3) discrimination accuracy of G1 individuals in stepwise discriminant analysis was obviously lower than that of G1 populations; (4) G0 and G1 populations were clustered into two separate clusters in the cluster analysis. In conclusion, morphological differences between wild E. sinensis populations had disappeared after one generation of artificial culture, and morphology thus probably cannot be used to distinguish the pond-reared offspring originated from three wild E. sinensis populations.
Jie Gong, Wenyuan Shi, Ming Zhang, Tianfa Wang, Kun Yu and Haihui Ye
In arthropods, E75 is an important nuclear receptor to regulate various physiological processes, such as development and reproduction. In this study, a 3551 bp cDNA of E75 (SpE75) with a typical domain organization of the nuclear hormone receptor was cloned from Scylla paramamosain. A qRT-PCR analysis revealed that, during ovarian development, the expression of SpE75 significantly increased after the onset of vitellogenesis and reached its peak value at the early vitellogenic stage. In vitro and in vivo experiments showed that 20-hydroxyecdysone significantly induced the transcriptions of the genes of both SpE75 and vitellogenin in the ovary. During juvenile crab (C1) development, the expression of SpE75 increased from 0 h (postmoult stage) to 96 h (premoult stage) and kept a low level in the fasting crabs. Together, these results indicate that SpE75 may be playing an important role in the regulation of ovarian development and somatic growth, as a component of ecdysone signalling in crustaceans.
Jian Hua Chen, Meng Jie Wang, Xue Li, Hai Hua Wang, Huan Gao and Bin Lun Yan
Wnt4 (Wingless-type MMTV integration site family member 4) has been demonstrated to play critical roles in a wide variety of biological processes, including embryonic development, cell proliferation, and differentiation in vertebrates, but its function in crustaceans is still not clear. In the present study, the full-length wnt4 cDNA sequence was cloned and characterized for the ridgetail white prawn Exopalaemon carinicauda. The expression patterns of the wnt4 mRNA in embryos and larvae at different stages were investigated. The tissue distribution showed that wnt4 was obviously expressed in eyestalk and hepatopancreas. During embryonic development, the wnt4 was highly expressed in all developmental stages except the zygote, two-cell stage, and late zoaea stage. The wnt4 mRNA was expressed in Z1-Z5 and post-larval stages. Taken together, the present study indicates that the wnt4 gene may be involved in the regulation of embryonic and larval development in the ridgetail white prawn.
Helna Ameri Kottarathil and Sudha Kappalli
The present study explores the reproductive system of Norileca indica during its transitional and female phase at morphological, histological, ultrastructural and histochemical levels. The paired and symmetrical hermaphroditic reproductive system of N. indica in the transitional and female phases lies dorsally in the thorax on either side of the gut, each consisting of a three-lobed testis (with lobes t1, t2 and t3) followed by an ovary and then a vas deferens, which opens into the paired penes located at sternite 7; the oviduct, arising laterally from the ovarian lobe, opens into the gonopore located on the 6th pereonite. In the transitional phase, the gonads show a presence of germ cells at different maturation stages: spermiogenesis in the testes has already halted, while the ovary undergoes active vitellogenesis. Spermatophores are frequently seen in the vas deferens but seldom in the testes; the size of the oocytes then is 250-1200 μm. The gonadosomatic index (GSI) and nucleocytoplasmic index (NCI) range over 0.090-0.198 and 0.46-0.11, respectively. In the female, oocyte size increases to 1500 μm; the GSI ranges 0.019-0.235 and the NCI from 2.40 to 0.09; testes and vas deferens are not prominent. This paper discusses the possible role of protandrous hermaphroditism in the reproductive life of N. indica.
An examination of some benthic amphipods belonging to the genus Cheirocratus from Arcachon Bay revealed that they exhibited a combination of morphological character states that distinguished them from all previously described Cheirocratus species. In the form of the gnathopods, Cheirocratus pseudosundevallii is very close to two other European species: C. sundevallii and C. intermedius. An actualized key to the species of Cheirocratus is provided.
Heng Qian, Ming Zhao, Keji Jiang, Wei Wang, Wei Chen, Junxia Zhao, Tian Wang, Le Diao, Lingbo Ma and Fengying Zhang
Juvenile hormone (JH) has an important role in regulating the development of arthropods, and methyl farnesoate (MF) is the only juvenile hormone found in Crustacea to date. Juvenile hormone-binding proteins (JHBPs) bind to JHs and transport or deliver JH signals. In this study, the complete cDNA sequence of cytoplasmic JHBP (cJHBP) was obtained from Scylla paramamosain, which we named Sp-cJHBP. The putative protein sequence of Sp-cJHBP contains two conserved glyoxalase domains. Expression analysis revealed that Sp-cJHBP expression varied greatly among larval developmental stages, with a significant reduction at the Zoea-5 stage. Sp-cJHBP had the highest expression in the ovary, with low expression in other tissues of the female adult crabs. During ovarian development, the expression of Sp-cJHBP changed significantly in the ovary, though its trends correlated poorly with the ovarian developmental process. While the expression in the mandibular organ (MO) was similar to 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), which is a key gene involved in MF biosynthesis. After unilateral eyestalk ablation (ESA), the expression of Sp-cJHBP altered significantly in the ovary and MO, but not in cerebral ganglion and thoracic ganglion. Altogether, these results suggest that Sp-cJHBP is likely to function primarily in the ovary, probably through binding to MF.