Turban Shell Research Articles

Fluorescent amplified fragment length polymorphism and repetitive extragenic palindrome-PCR fingerprinting reveal host-specific genetic diversity of Vibrio halioticoli-like strains isolated from the gut of Japanese abalone.

When analyzed by fluorescent amplified fragment length polymorphism and repetitive extragenic palindrome-PCR fingerprinting, a total of 47 Vibrio halioticoli strains isolated from four Japanese abalone species and one turban shell species formed three clusters that roughly reflect the different species of host abalone from which they were isolated. The V. halioticoli isolates from turban shells were distributed evenly among the clusters. Representative isolates from two clusters were deemed separate species or subspecies by DNA-DNA hybridization.

Effects of starvation on RNA : DNA ratio, glycogen content, and C : N ratio in columellar muscle of the Japanese turban shell Turbo (Batillus) cornutus (Gastropoda)

: The validity of using the RNA : DNA ratio, glycogen content, and C : N ratio in the columellar muscle as indicators of the nutritional condition in the Japanese turban shell Turbo cornutus was examined. These biochemical indices were compared between fed and starved animals. The fed animals were fed brown algae to satiation for 108 days as a control, whereas the starved animals were not fed for the first 75 days and then fed for next 33 days. All three indices declined during the starvation period, and the values for the starved group were significantly lower than those for the fed group during days 20–75. At day 108, after the re-feeding period, the indices for the starved group were found to have increased. Among the indices, only the RNA : DNA ratio for the starved males responded rapidly to starved conditions and became significantly lower even at day 4, and only the RNA : DNA ratio for the starved males and females recovered to those levels of the fed animals at day 108. The results indicated that the RNA : DNA ratio is the most rapid indicator of nutritional stress among the three indices. However, it is recommended that glycogen content and C : N ratio be used in addition to the RNA : DNA ratio for monitoring the health of T. cornutus as the RNA : DNA ratio showed large variations.

Reproduction of the turban shell Turbo torquatus Gmelin 1791 (Mollusca : Gastropoda), in New South Wales, Australia

The Sydney turban shell Turbo torquatus is the focus of a small-scale commercial fishery in New South Wales. Effective management requires knowledge of the reproductive biology, yet this is lacking for NSW waters. The reproductive cycle was investigated at three localities on the southern New South Wales coast. Samples of T. torquatus were collected monthly at Wollongong, Ulladulla and Eden from February 1996 until August or December 1997. The reproductive cycle was investigated by three methods: monthly determination of a gonadosomatic index, estimation of oocyte size-frequency distributions and classification of female gonads into developmental stages following histological sectioning. Males and females within a population underwent synchronous gonad development and spawning. Spawning events were often protracted over a period of several months with females in various stages of gonadal development. Two spawning events occurred each year, with a spawning event in autumn–winter and another in spring–summer. These events were asynchronous among the three localities, and partial spawning appeared to be a common occurrence. Owing to variation in the timing of spawning between populations separated by a distance as small as 15 km, seasonal closures to protect spawning stocks are unlikely to be effective.

Identification of tropomyosin as a major allergen in the octopus Octopus vulgaris and elucidation of its IgE-binding epitopes

: The major allergen (named Oct v 1) in the muscle of the octopus Octopus vulgaris was purified by gel filtration on Sephacryl S-300, anion-exchange fast protein liquid chromatography on Mono Q and reverse-phase high-pressure liquid chromatography on TSKgel Octadecyl-4PW. In addition to the molecular mass, amino acid composition and cross-reactivity with Tur c 1 (turban shell Turbo cornutus allergen), the determined partial amino acid sequence clearly demonstrated that Oct v 1 is tropomyosin, similar to the known molluscan and crustacean allergens. Using peptide fragments isolated from the lysylendopeptidase digest of Oct v 1, competitive enzyme-linked immunosorbant assay inhibition experiments showed that IgE-binding epitopes of Oct v 1 are contained in two peptides (77–112 and 148–160) in the central region and one peptide (269–281) in the C-terminal region. In the peptide 77–112, the same sequence as the IgE-binding epitope proposed for Cra g 1 (oyster Crassostrea gigas allergen) is recognized at 92-105. Moreover, the peptide 148-160 partly overlaps with the IgE-binding epitopes suggested for Pen i 1 (shrimp Penaeus indicus allergen) and Pen a 1 (shrimp Penaeus aztecus allergen), and the peptide 269–281 with those for Tur c 1 and Pen a 1.

Abalone collagens: immunological properties and seasonal changes of their mRNA levels

The antisera were raised against pepsin-solubilized abalone collagen and its corresponding gelatin. The reactivity against abalone collagen was higher with the anti-collagen than anti-gelatin antiserum. The two antisera recognized all type I collagens from various vertebrates, whereas these had no reactivity against vertebrate type III and type V collagens. Furthermore, both antisera reacted with only α2(I) chains from chicken, rat, and calf. The strong reactivity was observed against the two antisera in the case of invertebrate and protochordate collagens, especially for turban shell collagen. The seasonal changes of collagen mRNA levels were examined in relation to those of collagen content. Haliotis discus collagens (Hdcols) 1α and 2α coding for abalone collagen proα-chains showed quite similar patterns. The highest mRNA levels in adductor and foot muscles for the two collagens were observed in December and January, in good agreement with the increase of collagen content. The mRNA levels decreased in July and August when collagen content decreased. These results indicate that collagen transcription levels are closely related to collagen contents.

Stability of the Courses of the Warm Coastal Currents along the Kyushu Island Suggested by the Population Structure of the Japanese Turban Shell, Turbo (Batillus) Cornutus

The genetic structure of a population of the Japanese turban shell, Turbo (Batillus) cornutus at Sata-Misaki Point, on the southern coast of Kyushu Island, was determined on the basis of nucleotide sequences of mitochondrial DNA and compared with that of a population of the western coast of Kyushu Island. The significant genetic differentiation between these two populations suggests that the courses of the warm currents along the coast of the Kyushu Island have been relatively stable after the divergence between the two genetically distant groups of the Japanese turban shell, which was estimated to have occurred during some period in Pleistocene.

Immunological Comparison of Shellfish Allergens by Competitive Enzyme-Linked Immunosorbent Assay

Allergens from five species of shellfishes (oyster Crassostrea gigas, scallop Patinopecten yessoensis, short-neck clam Tapes japonica, turban shell Turbo cornutus, and whelk Neptunea arthritica) were immunologically compared by competitive ELISA inhibition analyses. The cross-reactivity was recognized between shellfish allergens and Crag 1, the oyster allergen, suggesting that, irrespective of species, the major allergen in shellfishes is tropomyosin. When four synthesized overlapping peptides (P-1, LNRRIQLLEEDM; P-2, RIQLLEEDMERS; P-3, LLEEDMERSEER; P-4, EDMERSEERLQT), which comprehend a part of the sequence of K21 d (IgE-binding epitope proposed for Crag 1, IQLLEEDMERSEER), were subjected to competitive ELISA inhibition experiments, only P-3 inhibited the binding of Crag I to specific IgE antibodies in the sensitized serum. Comparison of the sequence of K21d with those of the four synthesized peptides revealed that both N- and C- terminal regions of K21d are essential for the binding to specific IgE antibodies. In addition, P-3 inhibited the binding of specific IgE antibodies to scallop and whelk allergens as well as oyster allergens, but substantially not to those from the other two species. It was thus concluded that shellfish allergens do not always have IgE-binding epitopes in the same regions, although they are all thought to be tropomyosins.

Genetic differentiation among populations of the Japanese turban shell Turbo (Batillus) cornutus corresponding to warm currents

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 150:149-155 (1997) - doi:10.3354/meps150149 Genetic differentiation among populations of the Japanese turban shell Turbo (Batillus) cornutus corresponding to warm currents Kojima S, Segawa R, Hayashi I The nucleotide sequences of a highly polymorphic region of the mitochondrial gene for cytochrome oxidase I (237 base pair) were determined for 240 individual specimens of the Japanese turban shell Turbo (Batillus) cornutus collected from 12 sites around Japan. Synonymous nucleotide substitutions were detected at 34 positions, and the 49 haplotypes obtained were divided into 2 clusters that formed 'star' phylogenies. The distribution of the 2 clusters was closely related to the pathways of the 2 warm currents along the Japanese Islands, namely, the Kuroshio and Tsushima Currents. The appearance of 2 clusters in the Japan Sea and the Seto Inland Sea is probably attributable to gene flow through the Kanmon Strait during the past 5000 yr. The genetic polymorphism found among the natural populations of the Japanese turban shell provides useful information with which to assess the anticipated genetic disturbance introduced by human activities, such as stocking with artificially bred juveniles. Genetic differentiation · Turbo (Batillus) cornutus · Warm currents · Mitochondrial DNA · Japan Sea Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 150. Publication date: April 30, 1997 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1997 Inter-Research.

Finding of a Homarine-Synthesizing Enzyme in Turban Shell and Some Properties of the Enzyme

A homarine-synthesizing enzyme was found for the first time in cell-free extract from turban shell (Batillus cornutus) and the enzyme was purified 36.2-fold and characterized. Properties of the enzyme were as follows: substrates were picolinic acid (pyridine-2-carboxylic acid) and S-adenosyl-L-methionine; optimum temperature for the enzymic reaction was 25°C; optimum pH for the enzymic reaction was 6.3; and the Km values for picolinic acid and S-adenosyl-L-methionine were calculated at 317 and 14.5 μM, respectively. Among pyridine carboxylic acids, only picolinic acid was methylated with S-adenosyl-L-methionine by this enzyme. The molecular weight of the enzyme was estimated to be 70,800. The enzyme activity was inhibited by heavy metal ions, S-adenosyl-L-homocysteine, adenosine, homocysteine, and sinefungin. Homarine, which is an osmotic pressure regulator, morphogen, etc.; is enzymatically synthesized by the methylation of picolinic acid with S-adenosyl-L-methionine and the enzyme activity may be controlled by S-adenosyl-L-homocysteine (reaction product) and its related compounds.

Feeding-stimulant activity of algal glycerolipids for marine herbivorous gastropods

Phagostimulant activity of glycerolipids such as digalactosyldiacylglycerol (DGDG), 6-sulfoquinovosyldiacylglycerol (SQDG), phosphatidylcholine (PC), phosphatidylethanolamine (PE), etc., have been examined using the Avicel plate method for three kinds of marine herbivorous gastropods, the abaloneHaliotis discus, the turban shellTurbo cornutus, and the topshellOmphalius pfeifferi. DGDG showed strong activity for all the test animals. SQDG was much less active than the other glycerolipids for abalone. The turban shell and the top shell responded more or less sensitively to all tested glycerolipids at doses of 10-20μg/sample zone.

Chemical studies on feeding inhibitors for marine herbivores. Part I. A simple feeding inhibitor assay for marine herbivorous gastropods and the sea urchin Strongylocentrotus intermedius and its application to unpalatable algal extracts.

A new bioassay procedure using Avicel plates has been established to screen algal feeding inhibitors for marine herbivorous gastropods, the abalone Haliotis discus, the turban shell Turbo cornutus and the top shell Omphalius pfeifferi and the sea urchin Strongylocentrotus intermedius, Application of this assay procedure to an Australian red alga Phacelocarpus labillardieri resulted in isolation of a macrocyclic γ-pyrone as a very potent feeding inhibitor for the marine herbivores mentioned above.

The susceptibility and/or resilience of Rocky Littoral molluscs to stock depletion by the indigenous coastal people of Transkei, Southern Africa

Coastal shell middens accumulated by indigenous people in the Nqabara/Human's Rock area of Transkei were analysed to obtain information on species and size preferences. These data are compared with analyses of middens resulting from a controlled exploitation experiment within the adjacent Dwesa Nature Reserve. Preferred prey items included the brown mussel Perna perna, the abalone Haliotis spadicea, the turban shell Turbo sarmaticus and various patellid limpets. Information on the life history characteristics and habitat preferences of these species has been used to predict whether or not a given shellfish population is likely to be susceptible or resilient to stock depletion as a result of traditional gathering practices. Perna perna and Patella oculus appeared to be the species most susceptible to depletion. Despite the improverished state of exploited populations there appears to be no evidence of recruitment failure. The persistence of these stocks is probably dependent on reproductive output from exploited populations and on larval immigration from adjacent refuge populations. Provided there is no change in gathering methodology, adequate replenishment of these stocks should be maintained.

Chemical studies on phagostimulants for marine gastropods. Part VII. A simple feeding stimulant assay for marine herbivorous gastropods, the turban shell Turbo cornutus and the top shell Omphalius pfeifferi.

We have already established a simple and reliable feeding stimulant assay method for the young abalone Haliotis discus using Avicel (crystalline cellulose) plates. We recently found this simple assay procedure applicable to other marine herbivorous gastropods, the turban shell Turbo cornutus and the top shell Omphalius pfeifferi. The methanol extracts of several species of algae were subjected to the assay. Both test animals showed their feeding preference to the extracts of most species of algae tested. The extract of the green alga U. perlusu was the most active.

Characterization of three types of turban shell Batillus cornutus muscle - Ultrastructure and protein composition.

Three types of turban shell Batillus cornutus muscle-foot, opercular and visceral-were examined under an electron microscope, and the results discussed in association with their differ-ences in muscle protein composition. Myofibrils of foot muscle were partially surrounded by a collagen fibril layer of about 1μm thickness. Diameters of thick filaments fell in a wide range of 22-70nm (mean value, 50nm). The myofibrils were found to be crossing each other at right angles. The opercular muscle showed a similar structure, except that the collagen fibril layer was clearly thinner. The visceral muscle which surrounds the viscera was composed of roughly parallel-running myofibrils whose thick filaments had a mean diameter of 50nm, Paramyosin contents in the myofibrillar protein were 29-41% through the three types of muscle. The paramyosin to myosin heavy chain ratios were 25 and 2.3 in the foot and opercular muscles, respectively, whereas the ratio in the visceral muscle was 1.4. The collagen to crude protein ratio was 45% in the foot, 34% in the opercular and 5% in the visceral muscle, roughly agreeing with their electron microscopic differences.

Heat‐Induced Tendering of Turban Shell (Batillus cornutus) Muscle

ABSTRACTThe foot, opercular and visceral muscles were excised from the turban shell Batillus cornutus, and their heat‐induced changes in toughness and ultrastructure were compared. When heated up to 30°C, the toughness of foot muscle decreased in the upper and middle regions, but increased in the lower region. The toughness of these three regions decreased at temperatures between 50‐70°C, where collagen might be denatured. Some changes in toughness were also observed in the opercular muscle by heating up to 30°C, whereas the toughness of visceral muscle remained unchanged over a wide range of temperature. Transmission electron microscopy showed that the intrinsic structure of collagen fibrils in each muscle was lost at 60°C, with partial swelling.

Bacterial transformation of paralytic shellfish toxins in coral reef crabs and a marine snail.

Incubation of gonyautoxins with tissue extracts prepared from two species of crab, Atergatis floridus and Eriphia scabricuia, and from the turban shell, Turbo argyrostoma, confirmed trans-formation of gonyautoxins to saxitoxin through reductive elimination of C-11 hydroxysulfate and N-1 hydroxyl moieties. The reaction did not take place under bacteriostatic condition, indicating that bacteria rather than tissue enzymes were responsible for the reduction. The bacterial role was further confirmed by the fact that Pseudomonas sp. and Vibrio sp. isolated from the viscera of the above animals similarly converted gonyautoxins into saxitoxin. The bioconversion explained, at least partly, the discrepancy that saxitoxin and neosaxitoxin were predominant in the crabs and snails while their food alga, Jania sp., contained only gonyautoxin-I, -II, and -III. In-cubation with bacteria showed little effect on saxitoxin.

High molecular weight calcium binding protein in the microsome of scallop striated muscle.

In the microsome of scallop adductor striated muscle, 30K, 55K, 90K, and 360K proteins were detected as calcium binding proteins by 45Ca autoradiography on the transferred nitrocellulose membrane after sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE). The 360K protein was directly extracted with Triton X-100 from the whole homogenate of striated portion of scallop adductor muscle and purified through DEAE cellulose and hydroxyapatite column chromatography. This purified scallop high molecular weight calcium binding protein (SHCBP) showed a faster mobility in SDS PAGE in the presence of Ca2+ than in its absence. The decrease of tryptophan fluorescence had a half maximum near pCa 7 and was slightly co-operative with Mg2+. UV absorbance was slightly increased with Ca2+. The CD spectrum also changed with Mg2+ and Ca2+. These results reflect that this SHCBP binds calcium ions under near physiological conditions. SHCBP-like high molecular weight calcium binding proteins were also detected in the smooth muscle portion of adductor muscle and branchiae of scallop by 45Ca autoradiography, but not in liver. The adductor muscle of clam had a high molecular weight calcium binding protein whose molecular weight was a little smaller than that of SHCBP. The foot of turban shell had the same molecular weight calcium binding protein as SHCBP. Stains-all, a cationic carbocyanine dye, which has been reported to stain calcium binding proteins blue, stained SHCBP blue. The spectrum of SHCBP stained with Stains-all was very similar to that of calsequestrin. Although the function of SHCBP is still unknown, it might be expected to correspond to calsequestrin of vertebrate skeletal muscle, a calcium sequestering protein, in the sarcoplasmic reticulum.

Studies on paralytic shellfish poisoning in tropical waters. Analysis of paralytic shellfish toxins of marine snails.

The green turban shell Turbo marmorata, the turban shell Turbo argyrostoma, and the top shells Tectus pyramis and Tectus nilotica maxima, all collected on coral reefs of Ishigaki Island, Okinawa, were found to contain paralytic shellfish poisons in the viscera. The regional and seasonal variation in toxicity strongly suggested an exogenous origin of the toxins. The feeding habits and habitat of the gastropods suggested that the primary source of the toxins was a benthic organism. The analysis of the toxin composition of the first three species revealed a trace amount of gonyautoxin III in T. argyrostoma and a small amount of gonyautoxin II and neosaxitoxin in all three species. Saxitoxin was the most abundant component in all species, . The next most abundant component was found to be a new toxin, which was named turban shell toxin (TST). It was difficult to distinguish TST form saxitoxin by Bio-Rex 70 column chromatography and electrophoresis, but TST was separable from saxitoxin by thin layer chromatography.

Turboverdin, a new bile pigment from a turban shell, Turbo cornutus

1. 1. A new bile pigment was isolated from the ovary of a turban shell, Turbo cornutus as the chromophore of a biliprotein. 2. 2. The bile pigment was designated as turboverdin. 3. 3. By means of chemical and spectral methods turboverdin dimethyl ester was found to differ from mesobiliverdin dimethyl ester only in that an ethanol side chain replaces the ethyl group in the pyrrole ring A. 4. 4. Turboverdin may be the first instance in which a bile pigment with an ethanol group has been obtained from natural sources.

Isolation and characterization of a biliprotein from the ovary of a turban shell, Turbo cornutus.

A dark blue chromoprotein was isolated and purified from the ovary of a turban shell, Turbo cornutus, by ammonium sulfate fractionation and Sepharose-4B gel fltration. The chromoprotein behaved homogeneously both in starch gel electrophoresis and in ultracentrifugation. Its absorption maxima appeared at 278, 374, 535-540, and 600-605 nm in acidic solution. The molecular weight was 540, 000 with s20, w of 16S. The protein moiety which had been separated from the chromophore by the HCl-acetone treatment was analyzed for amino acid composition. The chromophore was proved to be a new bilatriene on the basis of its U. V. and visible spectra, its thin layer chromatographic behavior, a coloration test, and a chromic acid-dichromate degradation test.