Jakov Dulčić, Pero Tutman and Branko Dragičević
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.
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.
Selmeg V. Bazarsadueva, Larisa D. Radnaeva and Arnold K. Tulokhonov
In this report, we have compared the fatty acid composition of the endemic Lake Baikal amphipods Ommatogammarus albinus (Dybowsky, 1874) and Parapallasea lagowskii (Dybowsky, 1874). Specimens were sampled using the deep-water manned submersible “Mir” at the oil-methane seeps of Cape Gorevoy Utes and at a hydrothermal vent in Frolikha Bay. High levels of monounsaturated fatty acids and relatively low levels of saturated and polyunsaturated fatty acids were detected in the studied amphipods, with oleic and palmitic acid representing the main fatty acid components. The habitat of the amphipods exerted a profound effect on their fatty acid profile: the amphipods of Gorevoy Utes contained higher levels of linolenic 18:3n3 and arachidonic 20:4n6 acids, while the amphipods of Frolikha Bay contained higher levels of eicosapentaenoic 20:5n3 and docosahexaenoic 22:6n3 acid. Based on these findings, we suggest that the amphipods’ diet in different areas of Lake Baikal determines their fatty acid composition.
Sandra-Florina Lele and Lucian Pârvulescu
Heterochely is an important feature in some marine decapod crustaceans, but it is seldom investigated in freshwater crayfish. In this study, we applied a biometrical analysis targeting wild populations of three European crayfish species, Astacus leptodactylus, Astacus astacus, and Austropotamobius torrentium, as well as one invasive North American species, Faxonius limosus. Field data were combined with video-recorded observations to understand the usage of chelae in laboratory experiments for A. leptodactylus and F. limosus. According to biometrical measurements, heterochely was evenly distributed between species and sexes in wild populations, leading to the assumption that there is no specific pattern in chela size. Moreover, we found that the ambidextrous usage of chelae is a commonly encountered behaviour in crayfish, since no significant relationship was found between their chelae and asymmetry. This behaviour could maximize the chances of survival for crayfish in general, since losing one or both chelae is often recorded in the wild.
Juliana Gaeta and Raúl Cruz
Lobsters are recognizable faunal elements that play an important role as top predator in the trophic webs in benthic ecosystems and have an economic importance due to the intensive and valuable fishery. In Rocas Atoll (03°51′S 33°48′W) the presence of five species of lobsters in low tide pools was observed by visual census. These were: Enoplometopus antillensis Lütken, 1865; Palinurellus gundlachi Von Martens, 1878; Panulirus argus (Latreille, 1804); Panulirus echinatus Smith, 1869; and Parribacus antarcticus (Lund, 1793). This atoll appears to be dominated by P. echinatus followed by P. argus, P. antarcticus, P. gundlachi and E. antillensis, respectively. We also observed the presence of some potential predators that perhaps feed on lobster species and control these populations in the atoll. This work and future information could help to better understand the variability of lobster diversity and density in this unique atoll.
Laura Sanvicente-Añorve, Santiago Aréstegui-Paz Rubio, Elia Lemus-Santana, Eugenia Allende-Arandía and Jorge Zavala-Hidalgo
The distribution and abundance of hippoid zoeal stages offshore Veracruz, southern Gulf of Mexico, and the migration routes of these larvae in the western Atlantic, were analysed. Samples were collected with a Bongo net and larval dispersal was analysed applying the HYCOM hydrodynamical model; particles (virtual larvae) originating from 35 sites were tracked for 77 days. Larvae of Albunea paretii Guérin-Méneville, 1853 were the most abundant, and dispersal simulations indicated that older larvae occurring off Veracruz might originate from Texas. However, a substantial proportion of self-recruitment (7.8%) can occur, mainly due to the seasonal changes in direction of currents over the shelf as well as the high variability in weather conditions. Results also suggest that several generations of A. paretii are needed for the species to reach Veracruz from South America. A hypothetical model regarding the migration routes of A. paretii larvae in the western Atlantic is proposed.
Elena Marco-Herrero, Klaus Anger and Liliam Hayd
The postembryonic development of Macrobrachium pantanalense, a freshwater shrimp from central South America, was experimentally studied in the laboratory. In contrast to most other hololimnetic Caridea, this species passes through an extended larval phase with intraspecific variability in the number and morphology of stages. Here we describe the shortest developmental pathway comprising nine zoeal stages, the first post-zoeal stage (morphologically transitional between a late larva and an early juvenile), and an early juvenile with vestiges of larval traits. Post-zoeal development is characterized by a gradual reduction of the natatory exopods of the pereiopods (a larval character) and a concurrent transformation of the endopods to walking legs (juvenile trait). A comparison with the larvae of a closely related, often confused estuarine species from northern South America, M. amazonicum, revealed consistent interspecific differences, especially in the morphology of the fifth pereiopod, allowing for an unambiguous distinction of these two allopatric congeners.
Patricio De los Ríos, Jaime Pizarro-Araya, Fermín M. Alfaro and Carlos Zuleta
The crustacean communities in Chilean seasonal pools have been poorly studied, and much of the existing literature is restricted to southern Patagonian plains, whereas there are no studies available about other sites. The aim of the present study is to describe the aquatic crustaceans in shallow pools in Huentelauquén (31°S, central northern Chile). The species reported upon include Daphnia ambigua, Simocephalus serrulatus, Boeckella gracilipes, Ostracoda, and two unidentified clam shrimps (genera Lynceus and Leptestheria), which latter ones represent the first record of these taxa for Chile. The ecological results revealed low species numbers and non-structured patterns in the various species associations. The exposed results are markedly different from observations on other Chilean seasonal pools, where no clam shrimps can be found, and where primarily cladocerans, copepods, and amphipods occur in the crustacean communities.