The purpose of this study was to estimate one of the important aspects of amphipod laboratory culturing — the effect of different types of nutrition on the key biochemical markers widely used in biomonitoring. The study was performed with the Baikal endemic amphipod species Eulimnogammarus verrucosus (Gerstfeldt, 1858), E. cyaneus (Dybowski, 1874), and Gmelinoides fasciatus (Stebbing, 1899). These species are characterized by different ecological properties and evolutionary history. The results of the study demonstrate that a long-term laboratory exposure to different diets has a direct effect on vital and physiological parameters of the species’ adaptation (mortality, weight, protein concentration). Also, feeding imposes its influence on the common stress-markers of oxidative stress (activities of peroxidase, catalase, glutathione S-transferase), and on anaerobic metabolism (activity of lactate dehydrogenase) in Baikal amphipods, and this effect has a species-specific character. The results should be taken into consideration in future ecophysiological experiments performed with amphipods.
Spatial and temporal distribution patterns of the warrior swimming crab Callinectes bellicosus fishery in the Mexican Pacific were investigated. Geo-referenced commercial trap capture data derived from 44 trips in the Bahia Magdalena were analysed. Three fishing zones (Z1, inner; Z2, middle; Z3, mouth of the bay) and two climate seasons (warm, July-December; and cold, January-June) were defined previously. There were 1099 traps in Z1, 715 in Z2 and 2111 in Z3; in the warm season, 2091 traps were checked, whereas 1834 were checked in the cold season. The average number of individuals per trap (CPUE) varied by sex, zone and season, however, male crabs always predominated. During the warm season, large males (CW > 115 mm) exhibited the greatest value of CPUE. On average, the males represented 77% during the warm season and 84% during the cold season. The average size of the males (125 ± 0.843 mm CW) was significantly higher than the average size of females (121 ± 1.140 mm CW). The catch was composed of large mature males but females were absent in Z1; in comparison, both large mature males and females, in addition to ovigerous females, composed the catch at the mouth of the bay (Z3). Crab abundance was notably reduced in the cold season, especially for female crabs. The temporal behaviour of the warrior swimming crab in Bahia Magdalena is similar to that reported from the coastal lagoons of the Gulf of California; however, the low presence of females throughout the year could be related to their preferred environmental conditions, which include deeper areas with more current circulation, like those that occur at the mouth of the bay. These data corroborate the necessity to interpret with caution the crab population dynamics solely based on results derived from fishing with traps in coastal lagoons.
Dans ce travail, nous avons analysé les préférendums photique, thermique, hygrique et granulométrique de trois espèces d’isopodes terrestres : Armadillidium vulgare (Latreille, 1804), A. granulatum (Brandt, 1833), et Porcellio laevis Latreille, 1804 en réponse à un champ magnétique statique (CMS) (0 Hz, 200 mT). Les animaux exposés au CMS montrent une augmentation significative du nombre des spécimens photophiles et une diminution significative des animaux photophobes. Ces cloportes montrent aussi une diminution significative des spécimens préférant le froid et une augmentation significative de ceux préférant le compartiment chaud. Cette exposition au CMS cause un inversement très significatif du choix préférentiel du compartiment humide au compartiment sec chez A. vulgare et P. laevis, alors que ce changement n’est pas significatif chez A. granulatum. Cette même exposition a entrainé une nette perturbation du choix de la granulométrie du substratum, en particulier pour le gravier chez A. vulgare.
In this study, the conditions for establishment of a primary cell culture of haemocytes from the Australian red claw crayfish, Cherax quadricarinatus, were investigated. Five commercial media were assessed for haemocyte viability: Leibovitz L-15 medium (L-15), modified Leibovitz L-15 medium (ML-15, 2 × concentration), Grace’s insect medium, DMEM medium, and I-max medium. In addition, L-15 and Grace’s insect medium supplemented with 10%, 15%, and 20% charcoal-dextran-treated foetal bovine serum (FBS) were assessed for their effects on haemocyte growth. The optimal culture system was established as follows: L-15 basal medium with the addition of 0.4 g/l glucose, 2 g/l NaCl, 10% FBS, 100 U ml−1 penicillin, 100 μg ml−1 streptomycin, and pH 7.2-7.4. In addition, Giemsa staining of the cultured haemocyte monolayer revealed that two types of cell could be observed: semigranular cells (SGC) and granular cells (GC). Our study could enable further investigation of the immune function in this species.
This paper deals with six crustacean species associated with Posidonia oceanica (Linnaeus) Delile, 1813 meadows along the Aegean coasts of Turkey: Caprella tavolarensis, Eriopisella ruffoi, Iphimedia vicina, Astacilla mediterranea, Apseudopsis minimus and Macropodia deflexa. Apseudopsis minimus is a new record for the Turkish coast of the Aegean Sea, the other five species are new records for the eastern Mediterranean. Brief descriptions of the species and their morphological and ecological characteristics are given.
Euphausia superba is an abundant element in the marine plankton on the planet. Despite substantial research on this species, there is no comprehensive understanding of the population genetics of E. superba yet. In this study, the ND6 gene was used to assess the genetic variation in E. superba. In the South Shetland Islands, the population of E. superba shows abundant genetic variation, but we found a lack of genetic structure. An analysis of the demographic history suggested that a sudden expansion has been responsible for its high biomass. Our study could not only broaden our comprehension of E. superba, but also provide more scientific information on fisheries resources exploitation, biodiversity conservation and the maintenance of a proper ecological balance.
A new species of Stegocephalidae, Parandania unicoxae sp. nov., is reported from hydrothermal vents in the Okinawa Trough. It is the fourth species described in the genus Parandania Stebbing, 1899. The new species is most similar to P. boecki (Stebbing, 1888), but it can be readily distinguished from P. boecki by the unilobate coxae 6-7.
A new species of the genus Siriella is described based on specimens collected from an intertidal reef area at Port Dickson, Malaysia. The species shows modified setae on both rami of both the third and fourth male pleopods and coiled pseudbranchial rami on the second to fourth male pleopods. These morphological characteristics indicate that the present species is a member of the pacifica-group of the genus Siriella. This is the first species of the group from Southeast Asian waters other than the species,”Siriella inornata Hansen?”, described by O. S. Tattersall (1960). The morphological characters of the present species are compared with those of the species of the pacifica-group, including O. S. Tattersall’s (1960) species.