Chelonodon Patoca Research Articles

Chelonodontops bengalensis Habib et al. 2018, a junior synonym of Tetrodon patoca Hamilton 1822, with a type species designation for Chelonodon Müller 1841

A comparison of the recent description of Chelonodontops bengalensis Habib, Neogi, Og, Lee & Kim 2018 with that of Tetrodon patoca Hamilton 1822 reveals that the former is a junior synonym of the latter. Chelonodon patoca appears to be restricted in its distribution to coastal brackish waters at the mouth of the Ganges/Brahmaputra/Meghna system in India and Bangladesh and further south to at least the mouth of the Mahanadi. The valid name for the widespread Indo-Pacific species previously confused with C. patoca is C. kappa Hamilton 1822. We show that Bleeker (1850), not Rüppell (1852), was the first author to include pufferfish species in the genus Chelonodon Müller 1841, and as first revisers we choose Tetrodon kappa Hamilton 1822 as the type species of Chelonodon.

Japanese Planocerid Flatworms: Difference in Composition of Tetrodotoxin and Its Analogs and the Effects of Ingestion by Toxin-Bearing Fishes in the Ryukyu Islands, Japan

Tetrodotoxin (TTX), known as pufferfish toxin, is a potent neurotoxin blocking sodium channels in muscle and nerve tissues. TTX has been detected in various taxa other than pufferfish, including marine polyclad flatworms, suggesting that pufferfish toxin accumulates in fish bodies via food webs. The composition of TTX and its analogs in the flatworm Planocera multitentaculata was identical to those in wild grass puffer Takifugu alboplumbeus. Previously, Planocera sp. from Okinawa Island, Japan, were reported to possess high level of TTX, but no information was available on TTX analogs in this species. Here we identified TTX and analogs in the planocerid flatworm using high-resolution liquid chromatography–mass spectrometry, and compared the composition of TTX and analogs with those of another toxic and non-toxic planocerid species. We show that the composition of TTX and several analogs, such as 5,6,11-trideoxyTTX, dideoxyTTXs, deoxyTTXs, and 11-norTTX-6(S)-ol, of Planocera sp. was identical to those of toxic species, but not to its non-toxic counterpart. The difference in the toxin composition was reflected in the phylogenetic relationship based on the mitochondrial genome sequence. A toxification experiment using predatory fish and egg plates of P. multitentaculata demonstrated that the composition of TTX and analogs in wild T. alboplumbeus juveniles was reproduced in artificially toxified pufferfish. Additionally, feeding on the flatworm egg plates enhanced the signal intensities of all TTX compounds in Chelonodon patoca and that of deoxyTTXs in Yongeichthys criniger.

Anticancer potential of toxin extracts from vital organs of milk spotted puffer fish Chelonodon patoca on human cancer cell lines

Among aquatic creatures, fish are the most diversified organisms that have emerged among other vertebrates. The objective of this research was to evaluate the anticancer properties of toxin extracts from the marine puffer fish Chelonodon patoca. The toxins were extracted from the samples by homogenizing with acetic acid, and the clear supernatant was subjected to anticancer activities by MTT for cytotoxicity and cell viability on both Vero and cancer cell lines (A-549, AGS, HT-29, and MDA-MB-231). More than 70% of the normal cells were viable up to 200 µg/ml of toxin extracts so that hence the concentration was fixed below 200 µg/ml for the cell viability study on human cancer cells. Among the various organs, the toxin extracted from the liver showed potential antiproliferative activity at an inhibitory concentration of 50 µg/ml on HT-29 and MDA-MB231cell lines, 75 µg/ml on A549 and 100 µg/ml on AGS. The cellular and nuclear morphological changes, induction of apoptosis, and its stages were observed microscopically through different staining methods. Further, the DNA damage was confirmed by DNA fragmentation analysis to confirm apoptosis. The results suggest that the extract of toxin (liver) shows a significant antiproliferative effect on the human cancer cell lines.

Geographical differences in the composition of tetrodotoxin and 5,6,11-trideoxytetrodotoxin in Japanese pufferfishes and their origins

Tetrodotoxin (TTX)-bearing fish are thought to accumulate TTXs in their bodies through a food chain that begins with marine bacteria. However, the mechanism of TTXs transfer between prey and predators in the food chain remains unclear and the reasons for regional differences in pufferfish toxicity are also unknown. To investigate these matters, we collected juveniles of four species of pufferfish, Takifugu alboplumbeus, Takifugu flavipterus, Takifugu stictonotus, and Chelonodon patoca, from various locations in the Japanese Islands, and subjected them to liquid chromatography-tandem mass spectrometry analysis for TTX and its analog 5,6,11-trideoxyTTX (TDT). Concentrations of these substances tended to be higher in pufferfish juveniles collected from the Sanriku coastal area (Pacific coast of northern Japan) than in those from other locations. Juveniles had higher concentrations of TTX at all locations than of TDT. Mitochondrial cytochrome c oxidase subunit I (COI) sequences specific to the TTX-bearing flatworm, Planocera multitentaculata, were detected in the intestinal contents of up to 100% of pufferfish juveniles from various sampling sites, suggesting that P. multitentaculata was widely involved in the toxification of the juveniles in the coastal waters of Japan. A toxification experiment was conducted on three species of pufferfish juveniles (T. alboplumbeus, Takifugu rubripes and C. patoca) using TTX-bearing flatworm eggs harboring equal amounts of TTX and TDT. The TTX content of juveniles fed on flatworm eggs was found to be more than twice that of TDT, suggesting that pufferfish preferentially incorporate TTX compared to TDT.

The assessment of demersal fish community structure in Kuala Langsa estuary, Langsa City

The research was conducted from May to July 2022 in six zones to determine the diversity, niche width, distribution, and community structure of demersal fish. Fish were surveyed using a drift gillnet at a maximum depth of 15 m, identified, and analyzed using clusters and nMDS to determine their grouping. SIMPER analysis was used to discover individual variations between zones and depth strata, while ANOVA was used to determine the significance of individual fish observed. The results of the study found 8 species, 8 genera, and 8 families with Eubleekeria splendens as well as Chelonodon patoca having the highest niche widths (04.42 dan 04.33), then E. splendens, Terapon jarbua, Scatophagus argus, Plotosus canius, C. Patoca, and Johnius carouna were relatively abundant (frequency > 80%). Aside from that, J. carouna is the fish with the most individuals discovered (82 ind and 32.54%). Cluster analysis and nMDS are divided into two groups, with J. carouna being the differentiator between fish groupings based on zonation and C. chanos, C. patoca, and J. carouna being the differentiator between fish groupings based on depth strata. Furthermore, the ANOVA test reveals that individual demersal fish between zones have a significance of < 0.05, whereas individual demersal fish between depth strata have a significance of > 0.05.

Distribution of Marine Puffer and Porcupinefishes (Order: Tetraodontiformes) from Tamil Nadu Coast, Southern India

The marine pufferfishes (Family: Tetraodontidae) and porcupinefishes (Family: Diodontidae) were collected from major fish landing centres viz. Royapuram (station I), Cuddalore (station II), Nagapattinam (station III), Mandapam (station IV) and Kanyakumari (station V) along the Tamil Nadu coast, Southeast coast of India. Monthly sample collections were carried out for a period of 1 year from August 2014 to July 2015 from these five major fish landing centres. Overall, 12,112 fishes were collected which belongs to 15 species, 9 genera and two families Tetraodontidae and Diodontidae under the order Tetraodontiformes. It was also found that all the 15 species were not available in all the five stations. The collected 15 species were identified as Arothron immaculatus, A. reticularis, A. hispidus, A. stellatus, Arothron sp., Lagocephalus guentheri, L. sceleratus, L. lunaris, Takifugu oblongus, Torquigener brevipinnis, Chelonodon patoca, Canthigaster solandri, Diodon holocanthus, cyclichthys orbicularis and Chilomycterus reticulatus. The maximum distribution of pufferfishes was observed in Mandapam followed by Cuddalore, Nagapattinam, Royapuram and Kanyakumari. The present study clearly showed that 15 species of pufferfishes and porcupinefishes were reported which includes 6 additional distribution records as compared with previous literature. The study also presented the distributional updates of pufferfishes and porcupinefishes along with taxonomic features and figures for identification of species.

The planocerid flatworm is a main supplier of toxin to tetrodotoxin-bearing fish juveniles

Tetrodotoxin (TTX), a potent neurotoxin, is found in various phylogenetically diverse taxa. In marine environments, the pufferfish is at the top of the food chain among TTX-bearing organisms. The accumulation of TTX in the body of pufferfish appears to be of the food web that begins with bacteria. It is known that toxic pufferfishes possess TTX from the larval/juvenile stage. However, the source of the TTX is unknown because the maternally sourced TTX is extremely small in quantity. Therefore, the TTX has to be obtained from other organisms or directly from the environment. Here, we report evidence that the source of TTX for toxic fish juveniles including the pufferfish (Chelonodon patoca) and the goby (Yongeichthys criniger) is in the food organisms, as seen in their gut contents. Next generation sequencing analysis for the mitochondrial COI gene showed that the majority of the sequence recovered from intestinal contents of these toxic fishes belonged to the flatworm Planocera multitentaculata, a polyclad flatworm containing highly concentrated TTX from the larval stage. PCR specific to P. multitentaculata also showed that DNA encoding the planocerid COI gene was strongly detected in the intestinal contents of the goby and pufferfish juveniles. Additionally, the planocerid specific COI sequence was detected in the environmental seawater collected from the water around the sampling locations for TTX-bearing fish. These results suggest that planocerid larvae are the major TTX supplier for juveniles of TTX-bearing fish species.

Pufferfish Saxitoxin and Tetrodotoxin Binding Protein (PSTBP) Analogues in the Blood Plasma of the Pufferfish Arothron nigropunctatus, A. hispidus, A. manilensis, and Chelonodon patoca.

Pufferfish saxitoxin and tetrodotoxin (TTX) binding protein (PSTBP) is a glycoprotein that we previously isolated from the blood plasma of the pufferfish Takifugu pardalis; this protein was also detected in seven species of the genus Takifugu. We proposed that PSTBP is a carrier protein for TTX in pufferfish; however, PSTBP had not yet been found in genera other than Takifugu. In this study, we investigated the presence of PSTBP-like proteins in the toxic pufferfish Arothron nigropunctatus, A. hispidus, A. manilensis, and Chelonodon patoca. On the basis of ultrafiltration experiments, TTX was found to be present and partially bound to proteins in the plasma of these pufferfish, and Western blot analyses with anti-PSTBP antibody revealed one or two bands per species. The observed decreases in molecular mass following deglycosylation with glycopeptidase F suggest that these positive proteins are glycoproteins. The molecular masses of the deglycosylated proteins detected in the three Arothron species were larger than that of PSTBP in the genus Takifugu, whereas the two bands detected in C. patoca had molecular masses similar to that of tributyltin-binding protein-2 (TBT-bp2). The N-terminal amino acid sequences of 23–29 residues of these detected proteins were all homologous with those of PSTBP and TBT-bp2.

First report on distribution of heavy metals and proximate analysis in marine edible puffer fishes collected from Gulf of Mannar Marine Biosphere Reserve, South India.

In the present study, the heavy metal concentration in different organs (skin, tissue, liver, kidney, gill, intestine, and ovary) and muscle proximate composition were studied in marine edible puffer fishes Takifugu oblongus, Lagocephalus guentheri, Arothron hispidus, Chelonodon patoca and Arothron immaculatus collected from Mandapam fish landing centre, South east coast of India. Heavy metals (Cd, Cu, Pb & Zn) were analyzed in different organs for the above mentioned species. The heavy metals concentration ranges in fish organs of all the five species were Cu (0.42 -6.31mg/kg), Cd (0.01-0.79mg/kg), Pb (5.80-19.87mg/kg), and Zn (6.75-65.08mg/kg). Zn was detected higher in all the samples followed by Pb, Cu and Cd. The proximate composition was determined in edible muscle tissues of all the five species. The highest and lowest protein contents were observed in T. oblongus (20.6±0.6%) and C. patoca (17.9±0.3%). In the present study, heavy metal concentrations were found very high in all the internal organs when compared to muscle tissues. Further, this is the first report on distribution of heavy metals and proximate compositions of commercialized important edible puffer fishes from Mandapam coast of Gulf of Mannar, Southeast coast of India.

Length-weight relationships of five fish species from Hormozgan coastal waters (northeastern Persian Gulf)

Summary The study presents and describes the first length–weight relationships for five fish species: Lagocephalus inermis (Temminck and Schlegel, 1850); Chelonodon patoca (Hamilton, 1822); Ilisha megaloptera (Swainson, 1839); Pseudosynanceia melanostigma Day, 1875; and Chirocentrus nudus Swainson, 1839) from the coastal waters of Hormozgan in the northeastern Persian Gulf.

Effect of Liver Biotoxins of Certain Marine Fishes on Mouse Cell Culture

Biotoxins from certain marine fishes are not only harmful to marine animals and their native environment, but also have pharmacological importance, and can be used as medicines. An investigation was carried out to study the effects of liver biotoxins of marine fish (Chelonodon patoca), catfish (Osteogeneiosus militaries), and mackerel (Rastrelliger kanagurta) on mouse, and their established kidney and liver cell lines. Among the three toxins, puffer liver toxin was the most toxic in mouse, with 5 mouse units/ml, followed by 2.5 mouse units/ml and 0.67 mouse units/ml of catfish and mackerel, respectively. The morphological rigidity, viability, swelling and syncitia formation, followed by cell death, are the common features recorded in both cell lines. The Tissue Culture Infective Dose (TCID50) was the highest for puffer liver toxin in both cell lines, followed by catfish and mackerel liver toxin.

Distribution of Tetraodontiformes (Family: Tetraodontidae) along the Parangipettai Coast, Southeast coast of India

The present study discusses the distribution and systematic position of puffer fishes from coastal waters of Parangipettai along the southeast coast of India. The puffer fishes collected from three different stations (Mudasal odai, Annankoil and Samiyarpettai) included nine different species from five different genera: Lagocephalus, Arothron, Torquigener, Chelonodon and Takifugu in the order Tetraodontiformes and family Tetraodontidae, viz., Lagocephalus lunaris, Lagocephalus inermis, Arothron reticularis, Arothron hispidus, Arothron stellatus, Arothron immaculatus, Torquigener brevipinnis, Chelonodon patoca and Takifugu oblongus. This study also summarized the distribution and taxonomic positions in terms of species availability and key characters.

Liquid chromatography-tandem mass spectrometry determination of the toxicity and identification of fish species in a suspected tetrodotoxin fish poisoning.

Suspected tetrodotoxin (TTX) poisoning was associated with eating unknown fish in April 2009 in Taiwan. After ingestion of the fish, symptoms of the victim included perioral paresthesia, nausea, vomiting, ataxia, weakness of all limbs, respiration failure, and death within several hours. The toxicity in the remaining fish was determined, with the mice exhibiting symptoms of neurotoxin poisoning. The implicated fish and deceased victim tissues were analyzed for TTX by liquid chromatography-tandem mass spectrometry. The urine, bile, cerebrospinal fluid (spinal cord), pleural effusion, and pericardial effusion of the victim contained TTX. In addition, the partial cytochrome b gene of the implicated fish was determined by PCR. The DNA sequence in the partial 465-bp cytochrome b gene identified the implicated fish as Chelonodon patoca (puffer fish). These results indicate that people should avoid eating unknown fish species from fish markets where harvested fish may include toxic species.

Extension of range of the Marine Puffer Fish Chelonodon patoca (Tetraodontiformes: Tetraodontidae) to freshwater habitat of Kerala, India

Chelonodon patoca is a marine puffer fish common along the Coromandal Coast of India. It has also been reported in the Aghnashini River in Karnataka state, a freshwater habitat. During a recent ichthyological survey five specimens of Chelonodon patoca were collected in another freshwater habitat, the Payaswani River in Kerala state. These specimens document an extension in the distributional range from Karnataka to Kerala state in peninsular India.

Molecular identification of pufferfish species using PCR amplification and restriction analysis of a segment of the 16S rRNA gene

This study amplified the mitochondrial 16S rRNA gene using polymerase chain reaction (PCR) with a template of total DNA from muscle tissues of nine pufferfish species collected from the coastal area of Okinawa Islands in Japan: Pleuranacanthus sceleratus, Triodon macropterus, Chelonodon patoca, Sphoeroides pachygaster, Arothron hispidus, A. stellatus, A. manilensis, A. mappa, and A. nigropunctatus. Then nucleotide sequence encoding a partial region of the 16S rRNA gene was compared among species. The sequenced fragment was also used to select restriction enzymes, yielding species-specific restriction fragment length polymorphisms (RFLP). The sequence of the segment of the 16S rRNA gene consisted of about 615 nucleotides and showed interspecies variations in the targeted region. After calculation of corresponding RFLP-patterns of nine species investigated with suitable restriction enzymes, three restriction enzymes – BanII, DdeI, and NlaIII – were found to be sufficient for identification of all nine species. Successful testing of this methodology in frozen and heated food samples suggests its utility for pufferfish species authentication in food products.

Ecological monitoring for ascertaining the bio-safety of liver lipids from some Indian marine puffer fishes

Ecological investigations were carried out on Indian marine puffers, Chelonodon patoca, Sphaeroides oblongus, Lagocephalus lunaris and Lagocephalus inermis, the four major species available in the coastal waters of the Bay of Bengal, India. The seasonal intraspecific and interspecific abundance and average daily landings were noted. The high hepatosomatic index and low lipid ratio of muscle to liver indicated accumulation of lipid in the liver. The lipid content was at its maximum during the monsoon (July–October) in all the species as was observed from the study of the seasonal variation of liver lipids. The puffers are mainly bottom feeders and the molluscs Umbonium vesterium and Donax incarnatus are the major prey group, constituting 56.0–87.5% of their food content. The liver and ovary had the maximum toxicity in monsoon during their spawning season. The liver oils so far tested from these fishes had no toxicity and the study reveals that the ecologic information will be helpful in monitoring the quality for the safe isolation of polyunsaturated fatty acid —entiched oil from these non-conventional sources.

Intra-tissue distribution of tetrodotoxin in two marine puffers Takifugu vermicularis and Chelonodon patoca

Micro distribution pattern of tetrodotoxin (TTX) in several tissues of marine puffers Takifugu vermicularis and Chelonodon patoca was investigated by means of monoclonal antibody-based immunoenzymatic technique under light microscope. In the investigation TTX was visualized at glands in the skin of T. vermicularis, while in C. patoca TTX was detected in succiform cells of the skin section. Similarly, in the ovary section of T. vermicularis TTX was recognized at late peri nucleolus stage, yolk granule stage-I, and yolk granule stage-II of oocytes. The oocytes of late peri nucleolus stage and yolk granule stage-I showed TTX antigen at their nucleus and yolk vesicles, while in yolk granule stage-II TTX was visualized at yolk granules and yolk vesicles. In the ovary of C. patoca TTX was detected in the connective tissues and in the nucleus of some perinucleolar oocytes. In the liver and muscle of C. patoca TTX was found to be distributed in parenchymal hepatocytes and muscle fiber, respectively. This study, however, reveals that intra-tissue distribution of TTX varies in respect of species.

Studies on lipid and fatty acid compositions of puffer livers from Indian coastal waters with seasonal variation

AbstractThe puffer fishes Chelonodon patoca, Sphaeroides oblongus, Lagocephalus lunaris, and L. inermis of Indian coastal waters are wasted in huge quantity. The livers of these fishes were investigated for their lipid contents and fatty acid compositions in different seasons. It was found that monsoon season is the suitable time to obtain the maximal lipids (40.1–48.8%) from their livers, an amount similar to cod liver lipid content (39.5–55.0%). The fatty acids were mostly saturates and monoenes (60–70%). Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) concentrations (7–12%) were high during monsoon season. Neutral lipids were the predominant lipid class (>80%) and comprised triglycerides (277–674 mg/g) and cholesterol (0.6–3.1 mg/g). Quality indices of puffer liver lipids, e.g., specific gravity, refractive index, acid value, iodine value, saponification value and unsaponifiable matter, were evaluated. Puffer liver lipids were quantitatively and qualitatively comparable to other commercially important marine fish oils. The overall study suggests the possibility of future commercial utilization of liver lipids from puffer, an unconventional, cheap, and easily available source.

Occurrence of paralytic shellfish poison in Bangladeshi freshwater puffers

Two species of freshwater puffer fish, Tetraodon cutcutia and Chelonodon patoca, collected from several locations in Bangladesh, showed lethal potency in mice ranging from 2.0 to 40.0 MU/g tissue as paralytic shellfish poison. In both species, toxicity of the skin was generally higher than the other tissues examined (muscle, liver and ovary). Water-soluble toxins from T. cutcutia were partially purified by activated charcoal treatment followed by column chromatographies using Bio-Gel P-2 and Bio-Rex 70. Analyses by cellulose acetate membrane electrophoresis and high-performance liquid chromatography with fluorometric detection demonstrated that the toxins were composed of saxitoxin, decarbamoylsaxitoxin, gonyautoxins 2 and 3, decarbamoylgonyautoxins 2 and 3, and three unidentified components which are possibly related to paralytic shellfish poison.

A Preliminary Study of Puffer Fishes and Their Toxins Found in Hong Kong Waters

Puffer fishes are commonly found in Hong Kong waters. For this study, we collected and identified six species of local puffers, Takifugu niphobles (Jordan and Snyder), Takifugu alboplumbeus (Richardson), Chelonodon patoca (Hamilton-Buchanan), Lagocephalus spadiceus (Richardson), Takifugu ocellatus (Osbeck) and Diodon holocanthus (Linnaeus). The first three species were confirmed to be toxic (6-120 mouse units (MU)/g) by mouse bioassay. To isolate tetrodotoxin (TTX) from a common local puffer, Takifugu niphobles, two hundred grams of viscera (ovary, intestine and liver) was minced and extracted with acidic methanol. The crude toxin obtained was further purified by Sephadex G-50-50 gel filtration and Whatman CM-52 cation exchange column chromatography. Purification afforded two unidentified toxins, unknown 1 and unknown 2, which gave single fluorescent spots under UV irradiation (366nm) with Rf values of 0.80 and 0.54, respectively, in thin layer chromatography (TLC). The electrospray ionization mass spectra (ESI/MS) of unknowns 1 and 2 had their molecular ion peaks (M+H)+ at m/z 320 and 255, respectively. Unknown 1 was concluded to be TTX, whereas unknown 2 was probably a derivative of TTX, whose exact identification would require further chemical analyses.