Sclerites in different tissues of Mediterranean Echinodermata

The presence of sclerites in different mesodermal tissues was studied in thirteen species of Mediterranean echinoderms representing the five living classes. In the species of Asteroidea and Crinoidea examined, sclerites were present only in specific tissues. In the species of Ophiuroidea and, especially, Echinoidea and Holothuroidea examined, sclerites were present in almost every tissue, but with considerable variation among species and tissues. Data on sclerite shape, size, and relative abundance (measured as tissue abundance) are presented. The data support the possible functional role of sclerites as reinforcing structures, as well as their possible use as taxonomic characters. Finally, the need of more studies to elucidate the ontogenetic and phylogenetic implications of sclerites is discussed.     

Echinoderms (Echinodermata) of the Mexican Caribbean

A systematic list of the echinoderms of the Mexican Caribbean based on museum specimens of the Colección Nacional de Equinodermos, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México and the National Museum of Natural History, Smithsonian Institution, Washington, D.C. is presented. This list reveals an important echinoderm biodiversity in the Mexican Caribbean, where five of the six echinoderm classes are represented. A total of 178 echinoderm species is recorded, distributed in 113 genera, 51 families and 22 orders. 30 new records for the Mexican Caribbean are presents: Crínoidea (three), Asteroidea (two), Ophiuroidea (eleven), Echinoidea (one), Holothuroidea (thirteen).     

Inventory of echinoderms in the Iles Eparses (Europa,Glorieuses, Juan de Nova), Mozambique Channel,France

The multidisciplinary programme BioReCIE (Biodiversity, Resources and Conservation of coral reefs at Eparses Is.) inventoried multiple marine animal groups in order to provide information on the coral reef health of the Iles Eparses. All five classes of echinoderms were observed by visual census, photographed and later identified. About 100 species are reported, including a few unidentified ones which require further studies. The Holothuroidea and Ophiuroidea are the most diverse. One new species, the asterinid Aquilonastra chantalae O'Loughlin and McKenzie (2013), was discovered in addition to several new records of echinoderms. The illegal fishery targeting holothurians, which are presently highly valuable resources in this zone, is discussed.     

Marine invertebrates of the Sea of Okhotsk as a new source of lypopolysaccharide-binding proteins

Invertebrates from the Sea of Okhotsk were studied as a source of proteins that are capable of binding to lipopolysaccharides (LPSs) of gram-negative bacteria. A DOT analysis using dansyl-labeled LPS that we developed revealed LPS-binding proteins in blood-cell lysates of 21 out of 33 investigated species of invertebrates. Most of the investigated species with positive LPS-binding activity were decapod crustaceans (class Malacostraca, phylum Arthropoda). Hemocyte lysates from the red king crab Paralithodes camtschaticus and the sculptured shrimp Sclerocrangon boreas contained several LPS-binding proteins with different molecular weights. LPS-binding proteins were found for the first time in echinoderms (classes Holothuroidea, Asteroidea, and Echinoidea), sipunculans, and brachiopods.     

Echinoderms (Echinodermata) from the Mexican waters of the Gulf of Mexico

We present a systematic list of the echinoderms from Gulf of Mexico's Mexican waters based on specimens of the Colecci6n Nacional de Equinodermos, Instituto de Ciencias del Mar y Limnologia, Universidad Nacional Aut6noma de México and the National Museum of Natural History, Smithsonian Institution, Washington, D.C. This list reveals an important echinoderm biodiversity present in the Gulf of Mexico, where five of the six echinoderm classes are represented. A total of 209 echinoderm species is recorded, distributed in 129 genera, 63 families and 25 orders. 31 new records for the Gulf of Mexico are presented: Asteroidea (16), Ophiuroidea (nine), Echinoidea (one) and Holothuroidea (five).     

The catecholaminergic nerve plexus of Holothuroidea

Catecholamines have been extensively reported to be present in most animal groups, including members of Echinodermata. In this study, we investigated the presence and distribution of catecholaminergic nerves in two members of the Holothuroidea, Holothuria glaberrima (Selenka, 1867) (Aspidochirotida, Holothuroidea) and Holothuria mexicana (Ludwig, 1875) (Aspidochirotida, Holothuroidea), by using induced fluorescence for catecholamines on tissue sections and immunohistochemistry with an antibody that recognizes tyrosine hydroxylase. The presence of a catecholaminergic nerve plexus similar in distribution and extension to those previously reported in other members of Echinodermata was observed. This plexus, composed of cells and fibers, is found in the ectoneural component of the echinoderm nervous system and is continuous with the circumoral nerve ring and the radial nerves, tentacular nerves, and esophageal plexus. In addition, fluorescent nerves in the tube feet are continuous with the catecholaminergic components of the radial nerve cords. This is the first comprehensive report on the presence and distribution of catecholamines in the nervous system of Holothuroidea. The continuity and distribution of the catecholaminergic plexus strengthen the notion that the catecholaminergic cells are interneurons, since these do not form part of the known sensory or motor circuits and the fluorescence is confined to organized nervous tissue.     

DNA barcoding discriminates echinoderm species

DNA barcode sequences (a 657-bp segment of the mtDNA cytochrome oxidase I gene, COI) were collected from 191 species (503 specimens) of Echinodermata. All five classes were represented: Ophiuroidea, Asteroidea, Echinoidea, Holothuroidea and Crinoidea. About 30% of sequences were collected specifically for this study, the remainder came from GenBank. Fifty-one species were represented by multiple samples, with a mean intraspecific divergence of 0.62%. Several possible instances of cryptic speciation were noted. Thirty-two genera were represented by multiple species, with a mean congeneric divergence of 15.33%. One hundred and eighty-seven of the 191 species (97.9%) could be distinguished by their COI barcodes. Those that could not were from the echinoid genus Amblypneustes. Neighbour-joining trees of COI sequences generally showed low bootstrap support for anything other than shallow splits, although with very rare exceptions, members of the same class clustered together. Two ophiuran species, in both nucleotide and amino acid neighbour-joining trees, grouped loosely as sister taxa to Crinoidea rather than Ophiuroidea; sequences of these two species appear to have evolved very quickly. Results suggest that DNA barcoding is likely to be an effective, accurate and useful method of species diagnosis for all five classes of Echinodermata.     

发光蚯蚓的发光体系研究进展

发光蚯蚓在世界范围内广泛分布。大多数发光蚯蚓的发光体系包含于蚯蚓体腔液内充满颗粒的细胞内。早期对不同种发光蚯蚓的生理学及生物化学方面的对比研究表明大多数发光蚯蚓的发光体系是类似的,但最近对线蚓科的两个种的研究发现它们不仅发光源的定位特殊,而且发光反应所需要的成分也明显不同于其他种类。本文对发光蚯蚓的发光器官和发光体系的研究现状及其进展进行了综述,并将有代表性的发光蚯蚓的发光体系进行了对比总结。     

Bioluminescence characteristics of Lake Shira water

Bioluminescence bioassays based on luminous bacteria (Photobacterium phosphopreum) and coupled enzyme system NADH-FMN-oxidoreductase-luciferase were adapted for monitoring the saline-water conditions of Lake Shira (Khakasia, Siberia). The differences in bioluminescence responses have been found to be related to the salt composition and the oxidation-reduction properties of water. Bioluminescent kinetics parameters, which are mostly sensitive to pollution under conditions of saline water, have been observed. The enzymatic system in the presence of 1,4-benzoquinone are shown to be more sensitive to redox characteristics of the salt water than this in the absence of 1,4-benzoquinone. 1,4-benzoquinone should be applied for the preparation of a model solution for the monitoring of redox properties of the salt water. Using this technique, the results of bioluminescence analysis are used to construct a heterogeneity map that characterizes the spatial and temporal water quality of lake Shira. A partial map was based on the bioluminescence characteristics of water samples taken along the shoreline, sampling stations in the different places and in different depths of the lake. It has been demonstrated that the bioluminescence assay measurements must be done within two hours after the sampling time.     

Gene expression and larval evolution: changing roles of distal-less and orthodenticle in echinoderm larvae

We describe the expression of the homeobox genes orthodenticle (Otx) and distal-less (Dlx) during the larval development of seven species representing three classes of echinoderms: Holothuroidea, Asteroidea, and Echinoidea. Several expression domains are conserved between species within a single class, including Dlx expression within the brachiolar arms of asteroid larvae and Otx expression within the ciliated bands of holothuroid larvae. Some expression domains are apparently conserved between classes, such as the expression of Dlx within the hydrocoel (left mesocoel) in all three classes. However, several substantial differences in expression domains among taxa were also evident for both genes. Some autapomorphic (unique derived) features of gene expression are phylogenetically associated with autapomorphic structures, such as Dlx expression within the invaginating rudiment of euechinoids. Other autapomorphic gene expression domains are associated with evolutionary shifts in life history from feeding to nonfeeding larval development, such as Otx expression within the ciliated bands of a nonfeeding holothuroid larva. Similar associations between evolutionary changes in morphology and life history mode with changes in regulatory gene expression have also been observed in arthropods, urochordates, and chordates. We predict that recruitment of regulatory genes to a new developmental role is commonly associated with evolutionary changes in morphology and may be particularly common in clades with complex life cycles and diversity of life history modes. Caution should be used when making generalizations about gene expression and function based on a single species, which may not accurately reflect developmental processes and life histories of the phyla to which it belongs.     

Diversity of the Luciferin Binding Protein Gene in Bioluminescent Dinoflagellates – Insights from a New Gene in Noctiluca scintillans and Sequences from Gonyaulacoid Genera

Dinoflagellate bioluminescence systems operate with or without a luciferin binding protein, representing two distinct modes of light production. However, the distribution, diversity, and evolution of the luciferin binding protein gene within bioluminescent dinoflagellates are not well known. We used PCR to detect and partially sequence this gene from the heterotrophic dinoflagellate Noctiluca scintillans and a group of ecologically important gonyaulacoid species. We report an additional luciferin binding protein gene in N. scintillans which is not attached to luciferase, further to its typical combined bioluminescence gene. This supports the hypothesis that a profound re‐organization of the bioluminescence system has taken place in this organism. We also show that the luciferin binding protein gene is present in the genera Ceratocorys, Gonyaulax, and Protoceratium, and is prevalent in bioluminescent species of Alexandrium. Therefore, this gene is an integral component of the standard molecular bioluminescence machinery in dinoflagellates. Nucleotide sequences showed high within‐strain variation among gene copies, revealing a highly diverse gene family comprising multiple gene types in some organisms. Phylogenetic analyses showed that, in some species, the evolution of the luciferin binding protein gene was different from the organism's general phylogenies, highlighting the complex evolutionary history of dinoflagellate bioluminescence systems.     

Same Temporal Niche,Opposite Rhythmicity: Two Closely Related Bioluminescent Insects With Opposite Bioluminesce Propensity Rhythms

Arachnocampa species, commonly called glowworms, are flies whose larvae use light to attract prey. Here we compare rhythmicity in two of the nine described species: the Tasmanian species, Arachnocampa tasmaniensis, which inhabits caves and wet forest, and the eastern Australian mainland species, A. flava, primarily found in subtropical rainforest. Both species show the same nocturnal glowing pattern in external (epigean) environments and the same inhibition of bioluminescence by light and both species show circadian regulation of bioluminescence. We find that the underlying circadian bioluminescence propensity rhythm (BPR) of the two species peaks at opposite phases of the day:night cycle. Larvae of A. flava, placed in constant darkness in the laboratory, bioluminesce during the subjective scotophase, typical of nocturnal animals, whereas A. tasmaniensis shows the opposite tendency, bioluminescing most intensely during the subjective photophase. In A. tasmaniensis, which are exposed to natural day:night cycles, light exposure during the day overrides the high bioluminescence propensity through negative masking and leads to a release of bioluminescence after dusk when the BPR is on the wane. A consequence is that A. tasmaniensis is able to start glowing at any phase of the light:dark cycle as soon as masking by light is released, whereas A. flava is locked into nocturnal bioluminescence. We suggest that the paradoxical BPR of A. tasmaniensis is an adaptation for living in the cave environment. Observations of bioluminescence in colonies of A. tasmaniensis located in the transition from a cave mouth to the dark zone show that glowing is inhibited by light exposure but a peak bioluminescence follows immediately after “dusk” at their location. The substantial difference in the circadian regulation of bioluminescence between the two species probably reflects adaptation to the cave (hypogean) habitat in A. tasmaniensis and the forest (epigean) habitat in A. flava. (Author correspondence: d.merritt@uq.edu.au)     

The evolutionary pathway of light emission in myodocopid Ostracoda

The evolutionary history of bioluminescence and iridescence in myodocopid ostracods was estimated by phylogenetic analysis of mitochondrial 16S ribosomal RNA sequences. The inferred phylogeny of the myodocopids suggests that the common ancestor of Myodocopida evaluated in this study exhibits iridescence. This type of light emission was once lost and recaptured independently in the descendant lineages. Bioluminescent species also evolved from non-luminous ancestral species. In the suborder Myodocopina, all the bioluminescent species form a monophyletic group, suggesting that bioluminescence evolved only once. Structural differences between two bioluminescent groups in the order Myodocopida suggests independent origins for bioluminescence.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 87 , 449–455.     

Longwave-sensitive visual pigments in some deep-sea fishes: segregation of ‘paired’ rhodopsins and porphyropsins

Summary Microspectrophotometric examination of individual rods, and partial bleaching of visual pigment extracts from three species of deep-sea fish,Aristostomias grimaldii, Malacosteus niger andPachystomias microdon, suggest the presence of a rhodopsin-porphyropsin system of paired pigments.Aristostomias andMalacosteus have a P552₂-P517₁ pair, whilePachystomias has a P544₂-P513₁ pair. In contrast to most pigmentpair systems, each pigment is restricted to a single class of rod, thus giving the fish two spectrally distinct classes of photoreceptor. It is suggested that the longwave sensitive rods are an adaptation enabling these species to perceive their own deep-red bioluminescence. The astaxanthin-based red tapetum inMalacosteus, and a chlorin-like pigment, possibly acting as a photosensitizer and found in the rod outer segments ofMalacosteus, may also act to increase longwave sensitivity.     

萤火虫的发光行为及其功能起源

发光生物因其活体能自发荧光而倍受关注,萤火虫(鞘翅目:萤科)是被研究最多的发光生物,因为成虫发光在其性选择以及求偶交配中起着重要作用.由于萤火虫的发光是一个消耗能量(ATP),的化学反应过程,因而其发光在成虫之外的虫态也具有重要意义.本文就萤火虫成虫和幼虫的发光行为、功能意义进行了综述,并结合萤火虫的饲养观察对其卵和蛹的发光行为进行了描述,探讨了卵和蛹的形态阶段发光的生物学功能以及生物荧光的起源进化.这将有助于理解萤火虫及其它生物自发荧光的本质和起源进化过程.     

Dinoflagellate bioluminescence: a comparative study of invitro components.

In vitro bioluminescence components of the dinoflagellates Gonyaulax polyedra, G. tamarensis, Dissodinium lunual, and Pyrocystis noctiluca were studied. The luciferases and luciferins of the four species cross-react in all combinations. All of these species possess high-molecular weight luciferases (200,000-400,000 daltons) with similar pH activity profiles. The active single chains of luciferases from the Gonyaulax species have a MW of 130,000 while those from P. noctiluca and D. lunula have a MW of 60,000. Extractable luciferase activity varies with time of day in the two Gonyaulax species, but not in the other two. A luciferin binding protein (LBP) can easily be extracted from the two Gonyaulax species (MW approximately 120,000 daltons), but none could be detected in extracts of either D. lunula or P. noctiluca. Scintillons are extractable from all four species, but they vary in density and the degree to which activity can be increased by added luciferin. Although the biochemistry of bioluminescence in these dinoflagellates is generally similar, the observations that D. lunula and P. noctiluca apparently lack LBP and have luciferases with low MW single chains require further clarification.     

Development of bespoke bioluminescent reporters with the potential for in situ deployment within a phenolic-remediating wastewater treatment system

A suite of ecologically relevant, site-specific bioreporters was constructed by transposon mutagenesis of microorganisms isolated from a polluted phenolic-remediating wastewater treatment system. Four Pseudomonad species were engineered to carry a stable chromosomal copy of the lux operon (luxCDABE) derived from Photorhabdus luminescens. These recombinant reporter microorganisms were tested for bioluminescence response to relevant phenol concentrations in the laboratory and to phenolic-containing effluents generated by an industrial wastewater treatment plant. The reporters displayed proportional responses of bioluminescence decay with increasing phenol concentrations up to 800 mg l(-1) of phenol. When deployed against samples from the treatment system, they showed superior operational range and sensing capabilities to that observed for industry standard microorganisms such as Vibrio fischeri. Specifically, the engineered strains accurately predicted toxicity shifts in all the treatment compartments under study (with phenolic concentrations ranging from approximately 10 to 600 mg l(-1)) with a low coefficient of variation of replicate determinations (between 1.16% and 8.32%). This work highlights the utility of genetic modification of native microorganisms from sites of interest to provide robust and ecologically relevant organism-based reagents for toxicity monitoring with the potential for in situ deployment.     

Catalogue of neritic-benthonic echinoderms (Echinodermata: Crinoidea, Echinoidea, Holothuroidea) from the Cuban Archipelago

This is an updated taxonomic catalogue of neritic-benthonic Echinodermata (Crinoidea, Echinoidea, Holothuroidea) from Cuba, that includes locality, range, habitat and depth where each species is found. The species list is based on the collections of the Oceanology Institute; Havana, and the "Felipe Poey" Museum (Havana University) Specimens for those collections were captured by a variety of field techniques, narcotized with Cloral hydrate, fixed in formalin and stored in 70-80% alcohol. A total of 53 species were recorded (eight Crinoids, 22 Echinoids and 23 Holothuroids), in 37 genera, 19 families and 12 orders. Ocnus suspectus (Ludwig, 1874) and Phyllophorus (Urodemella) occidentalis (Ludwig, 1885) are new records for Cuban waters.     

Echinodermata from São Sebastião Channel (São Paulo, Brazil)

Faunal inventories are extremely important, especially when focused on neglected groups, such as echinoderms, and concentrated on areas under intense anthropic activity such as the SAo Sebastilo Channel in Brazil (23 degrees 41' - 23 degrees 54' S and 45 degrees 19' - 45 degrees 30' W). Intertidal and upper sublittoral zone collections were performed at five sites of the Channel's continental margin from May to August 2001. The rocky substrate down to 19 m deep was surveyed by snorkeling and SCUBA diving from August 2002 to May 2004, on both margins of the Channel: continental (14 sites) and insular (10 sites). We report a total of 38 species of echinoderms (one Crinoidea, nine Asteroidea, 13 Ophiuroidea, nine Echinoidea and six Holothuroidea). Seven of those species have been recorded here for the first time for the Channel (four Asteroidea, two Ophiuroidea and one Echinoidea).