Ophiuroids Research Articles

Neurogenesis during Brittle Star Arm Regeneration Is Characterised by a Conserved Set of Key Developmental Genes.

Simple SummaryInjuries to the central nervous system most often lead to irreversible damage in humans. Brittle stars are marine animals related to sea stars and sea urchins, and are one of our closest evolutionary relatives among invertebrates. Extraordinarily, they can perfectly regenerate their nerves even after completely severing the nerve cord after arm amputation. Understanding what genes and cellular mechanisms are used for this natural repair process in the brittle star might lead to new insights to guide strategies for therapeutics to improve outcomes for central nervous system injuries in humans.Neural regeneration is very limited in humans but extremely efficient in echinoderms. The brittle star Amphiura filiformis can regenerate both components of its central nervous system as well as the peripheral system, and understanding the molecular mechanisms underlying this ability is key for evolutionary comparisons not only within the echinoderm group, but also wider within deuterostomes. Here we characterise the neural regeneration of this brittle star using a combination of immunohistochemistry, in situ hybridization and Nanostring nCounter to determine the spatial and temporal expression of evolutionary conserved neural genes. We find that key genes crucial for the embryonic development of the nervous system in sea urchins and other animals are also expressed in the regenerating nervous system of the adult brittle star in a hierarchic and spatio-temporally restricted manner.

Design of a Hall effect sensor controlled brittle star inspired composite robotic limb

This paper elucidates a method of actuation and feedback for hard-soft composite continuum pentapod appendages to enable both kinematic accuracy and gait. A feedback mechanism based on Hall effect sensors is integrated within a hard exterior/soft interior composite robotic limb, which is unaffected by actuator slippage, and provides accurate (sub 2°) end point measurements. The proposed method for actuation uses two actuators to control a full semi-spherical range of motion, an improvement to the use of three actuators more commonly reported in the literature. When applied to enable the gait of a complete brittle star inspired pentapod, we find that our design reaches a momentum of 0.52kg · m s −1, surpassing the momentum of previously reported untethered starfish inspired pentapods by 3.7 times.

Food web ecology of Gulf Stream flounder (Citharichthys arctifrons): a continental shelf perspective.

Gulf Stream flounder, Citharichthys arctifrons, are regularly observed in fish diets of the northeast U.S. continental shelf, yet lack commercial value and are often ignored. Similarly, Gulf Stream flounder diets of the Northwest Atlantic have remained largely unexamined, except for a brief period from 1976 to 1980. To better understand their role in the ecosystem, juvenile through adult Gulf Stream flounder were examined both as a predator and prey, and the magnitude of their feeding footprint (removal of prey biomass) was quantified for the northeast U.S. continental shelf. Their stomachs were sampled from 2005 to 2010, with the majority examined in the field macroscopically. Due to large proportions of unidentifiable prey, the effort was expanded in 2011-2012, and all stomachs were processed in the laboratory microscopically. Gulf Stream flounder were consumed by 15 fish, and what they eat (percentage mass and percentage frequency of occurrence) was documented by season, spatial region and year. Highly benthivorous, Gammaridea and Polychaeta dominated the diet in all years, seasons and regions, but Ophiuroidea (brittle stars) were also prominent in Southern New England during the spring. Gulf Stream flounder diets remained consistent across regions and time, with only a few feeding differences between seasons and one region. Relative to the productivity of benthos for this shelf ecosystem, the feeding footprint of Gulf Stream flounder was minor for their predominant benthic prey with a maximum percentage of benthos production eaten of 0.01% m-2 in Southern New England. With an ecosystem perspective, this feeding information offers a foundation for improving fisheries management among shared living marine resources considering benthic habitat and prey availability.

Diversity, structure and spatial distribution of megabenthic communities in Cap de Creus continental shelf and submarine canyon (NW Mediterranean)

The continental shelf and submarine canyon off Cap de Creus (NW Mediterranean) were declared a Site of Community Importance (SCI) within the Natura 2000 Network in 2014. Implementing an effective management plan to preserve its biological diversity and monitor its evolution through time requires a detailed characterization of its benthic ecosystem. Based on 60 underwater video transects performed between 2007 and 2013 (before the declaration of the SCI), we thoroughly describe the composition and structure of the main megabenthic communities dwelling from the shelf down to 400 m depth inside the submarine canyon. We then mapped the spatial distribution of the benthic communities using the Random Forest algorithm, which incorporated geomorphological and oceanographic layers as predictors, as well as the intensity of the bottom-trawling fishing fleet. Although the study area has historically been exposed to commercial fishing practices, it still holds a rich benthic ecosystem with over 165 different invertebrate (morpho)species of the megafauna identified in the video footage, which form up to 9 distinct megabenthic communities. The continental shelf is home to coral gardens of the sea fan Eunicella cavolini, sea pen and soft coral assemblages, dense beds of the crinoid Leptometra phalangium, diverse sponge grounds and massive aggregations of the brittle star Ophiothrix fragilis. The submarine canyon off Cap de Creus is characterized by a cold-water coral community dominated by the scleractinian coral Madrepora oculata, found in association with several invertebrate species including oysters, brachiopods and a variety of sponge species, as well as by a community dominated by cerianthids and sea urchins, mostly in sedimentary areas. The benthic communities identified in the area were then compared with habitats/biocenoses described in reference habitat classification systems that consider circalittoral and bathyal environments of the Mediterranean. The complex environmental setting characteristic of the marine area off Cap de Creus likely produces the optimal conditions for communities dominated by suspension- and filter-feeding species to develop. The uniqueness of this ecosystem and the anthropogenic pressures that it faces should prompt the development of effective management actions to ensure the long-term conservation of the benthic fauna representative of this marine area.

A Multidisciplinary Approach for A Better Knowledge of the Benthic Habitat and Community Distribution in the Central and Western English Channel

About 80% of the seabed of the English Channel (EC) is covered by coarse sediment, from coarse sand to pebbles. Quantitative data on the benthic macrofauna in these types of sediment remains are rare due to the difficulty of using grab corers in such hard substrates. The deepest central part of the EC (45–101 m depth) was prospected during two VIDEOCHARM surveys in June 2010 and June 2011 to increase knowledge of such sublittoral coarse sediment benthic habitats. Sampling focussed on a longitudinal transect in the deepest part of the EC (13 boxes), extending from the western approach to the Greenwich meridian. Both indirect (side scan sonar, Remote Operated Vehicule) and direct (grab sampling with benthos determination, and grain-size analyses) approaches were used and combined, permitting description of the benthic habitats and communities using seven methods. Five benthic EUNIS habitats (European Nature Information System) were reported: MC3215, MD3211, MC4, MC3212 and MC4215, of which two extended main habitats (MC3211 and M23212) corresponded to an eastern/western gradient from sandy gravel to sandy gravel and pebbles sediment. Three other spatially discrete habitats were associated with poor coarse sand and gravel habitats as well as sandy gravel and pebbles with the presence of the brittle star Ophiothrix fragilis. Taxonomic richness of both extended habitats was on the same order of magnitude as the coarse sand habitat reported elsewhere in the EC, whilst the abundances were among the lowest in deeper areas with low nutrient input and low primary production. The epifauna appeared relatively homogenous in this type of sediment at the scale of the sampling area and was not determined to assign a EUNIS habitat/class. ROV footage illustrated the presence of large epifauna and provided valuable information to ground truth in other sampling methods such as side scan sonar mosaic. Grab photos showing surface sediment was relevant to determine the sediment type, whilst granulometric analyses gave additional information on fine particles content (typically very low).

Twinkle twinkle brittle star: the draft genome of Ophioderma brevispinum (Echinodermata: Ophiuroidea) as a resource for regeneration research

BackgroundEchinoderms are established models in experimental and developmental biology, however genomic resources are still lacking for many species. Here, we present the draft genome of Ophioderma brevispinum, an emerging model organism in the field of regenerative biology. This new genomic resource provides a reference for experimental studies of regenerative mechanisms.ResultsWe report a de novo nuclear genome assembly for the brittle star O. brevispinum and annotation facilitated by the transcriptome assembly. The final assembly is 2.68 Gb in length and contains 146,703 predicted protein-coding gene models. We also report a mitochondrial genome for this species, which is 15,831 bp in length, and contains 13 protein-coding, 22 tRNAs, and 2 rRNAs genes, respectively. In addition, 29 genes of the Notch signaling pathway are identified to illustrate the practical utility of the assembly for studies of regeneration.ConclusionsThe sequenced and annotated genome of O. brevispinum presented here provides the first such resource for an ophiuroid model species. Considering the remarkable regenerative capacity of this species, this genome will be an essential resource in future research efforts on molecular mechanisms regulating regeneration.

Transcriptomic response of intertidal brittle star Ophiothrix exigua to seasonal variation.

Adaptation to seasonal change is essential for survival, and is especially critical for organisms living in physically harsh environments. Brittle stars (Ophiothrix), known as a keystone species, inhabiting the intertidal rocky ecosystem are affected by multiple stressors, but molecular insights into their adaptation remain poorly studied. In the present study, transcriptomic responses of Ophiothrix exigua from the intertidal habitats of the North Pacific Ocean during summer and winter are reported. A total of 12,844 differentially expressed genes (DEGs) were identified. Of these, 7102 genes were up-regulated and 5742 genes were down-regulated in summer relative to winter. One hundred fifty-two key DEGs, including 31 up-regulated and 121 down-regulated genes, were categorized into three major subcategories and seven subclasses. The key DEGs included heat shock cognate protein 70 (HSC70), toll-like receptor-2 (TLR2), cAMP-dependent protein kinase catalytic subunit beta-like isoform X2 (PKA), serine/threonine-protein kinase mTOR (MTOR), and ras-related c3 botulinum toxin substrate 1 isoform X1 (RAC1). Glutathione peroxidase-like (GPX) and tubulin superfamily members (TUBA, TUBB) were consistent across seasons. The main defense-related pathways in brittle star were phagosome, apoptosis, and glutathione metabolism. These findings would greatly enhance our understanding of the genomic basis of environmental adaptation in intertidal invertebrates.

A Method for 3D Printing and Rapid Prototyping of Fieldable Untethered Soft Robots.

Because they are made of elastically deformable and compliant materials, soft robots can passively change shape and conform to their environment, providing potential advantages over traditional robotics approaches. However, existing manufacturing workflows are often labor intensive and limited in their ability to create highly integrated three-dimensional (3D) heterogeneous material systems. In this study, we address this with a streamlined workflow to produce field-deployable soft robots based on 3D printing with digital light processing (DLP) of silicone-like soft materials. DLP-based 3D printing is used to create soft actuators (2.2 g) capable of exerting up to 0.5 Newtons of force that are integrated into a bioinspired untethered soft robot. The robot walks underwater at speeds comparable with its biological analog, the brittle star. Using a model-free planning algorithm and feedback, the robot follows remote commands to move to desired positions. Moreover, we show that the robot is able to perform untethered locomotion outside of a laboratory and in a natural aquatic environment. Our results represent progress in soft robot manufacturing autonomy for a 3D printed untethered soft robot.

Multiple Trophic Tracer Analyses of Subarctic Rhodolith (Lithothamnion glaciale) Bed Trophodynamics Uncover Bottom-Up Forcing and Benthic-Pelagic Coupling

We paired a survey of cryptofaunal abundance and rhodolith morphology with lipid, fatty acid, and stable isotope analyses to quantify nutritional patterns and trophic linkages of six dominant echinoderm, bivalve, gastropod, and polychaete species, two macroalgal species, seawater, and underlying sediment in a large (>500 m2) rhodolith (Lithothamnion glaciale) bed in southeastern Newfoundland (Canada). We found high densities of chitons (Tonicella marmoreaandT. rubra) and daisy brittle star (Ophiopholis aculeata), and overall species composition, rhodolith morphology (shape and size), and total rhodolith biomass were consistent with other studies of the bed, indicating high temporal stability. Our lipid and fatty acid analyses revealed high levels of phospholipids and unsaturated fatty acids combined with low sterols in all animal species, suggesting adaptation for enhanced cell membrane fluidity in a cold-water environment. They also showed that most taxa sampled feed on a shared resource; diatoms, and that (non-kelp) macroalgal detritus are a key food source within rhodolith communities. Our stable isotope analysis uncovered three distinct trophic levels; producers, suspension/filter feeders and grazers, and predators, and unveiled potential resource partitioning between first- (H. arctica) and second- (O. aculeataandTonicellaspp.) order consumers, whereby differences in feeding strategies enable utilization of specific components of the same organic and inorganic material. The unprecedented analytical resolution enabled by the combined use of three trophic tracers indicate that bottom-up forcing (as a mechanism of trophic control) and benthic-pelagic coupling (as a pathway of nutrient and energy flow) operate simultaneously, at least seasonally, in subarctic rhodolith beds.

The effects of the nonnative brittle star Ophiothela mirabilis Verrill, 1867 on the feeding performance of an octocoral host in a southwestern Atlantic rocky shore

The Pacific epizoic brittle star Ophiothela mirabilis Verrill, 1867 has widely spread and colonized hosts at high densities along the Western Atlantic. We assessed the impacts of O. mirabilis on the feeding performance of the preferred host Leptogorgia punicea (Milne Edwards and Haime, 1857) through in situ experiments using incubation chambers and estimated its putative effects on the benthic-pelagic coupling processes of a rocky shore system. The feeding rates and heterotrophic carbon inputs of L. punicea treatments with high colonization by O. mirabilis (5.4 ± 0.6 individuals cm−2 of host area; mean ± standard deviation) were compared to host controls naturally without brittle stars. No significant differences in host feeding performance were observed between the control and treatments. Overall, L. punicea ingested 3,047,118 ± 1,843,183 particles g DW (dry weight)−1 h−1, corresponding to 116.1 ± 159.0 µg of carbon (C) g DW−1 h−1. Therefore, although octocorals hosting O. mirabilis may have impaired polyp opening and extension, their feeding performance remains similar. In this sense, the impact of O. mirabilis on the carbon flux of the rocky shore system driven by octocoral ingestion is minimal. The grazing rate of 49.9 ± 68.3 mg C m−2 day−1 highlights the significant role of L. punicea in such benthic-pelagic coupling processes. Notwithstanding, further laboratory and field experimental studies assessing the effects on host taxa with distinct morphological and functional features are needed to better understand the responses of the recipient hard-bottom systems along the Western Atlantic to increasing densities of O. mirabilis.

Cytotoxic and antimicrobial activities of two new sesquiterpenoids from red sea brittle star Ophiocoma dentata

Bioactive compounds were extracted from a locally available brittle star; Ophiocoma dentata, collected from the Red Sea, Egypt. Two new sesquiterpenoids; 8, 11-epoxy-9(15)-himachaladiene-4-ol (O8-ophiocomane) and, 11-epoxy-9(15)-himachaladiene-4-ol (O7-ophiocomane) were isolated and characterized using appropriate techniques. Structure elucidation was estimated via 1D NMR, 2D NMR, FT-IR and mass spectroscopy analyses. The isolated compounds were tested for cytotoxic, antibacterial and antifungal activities. Pure compounds showed a dose dependent reduction in MCF-7 cells viability with LC50 of 103.5 and 59.5 μg/ml for compounds 1 and 2 respectively compared to the chemotherapeutic drug cisplatin (47.4 µg/ml). In vivo experiments showed that O. dentate extract significantly reduced tumor progression and improved hematological parameters and liver functions of tumor-bearing mice when administered either before or after tumor cells’ injection. The most remarkable antimicrobial effects of O. dentate crude extract were against Staphylococcus aureus, Vibrio damsela and Pseudomonasaeruginosa while the pure compounds showed activity against P. aeruginosa alone. Neither the crude extract nor the pure compounds have shown activity against Aeromonas hydrophila. These results indicates that O. dentata extract and newly isolated compounds have shown a promising cytotoxic, antiproliferative and antimicrobial activities that might be useful for pharmaceutical applications.

New Brittle Stars (Echinodermata, Ophiuroidea) from the Oligocene of the Mainz Basin, Germany

The fossil record of the Ophiuroidea is still patchy, especially in the Cenozoic. Only four species have been described from the entire Oligocene, which is in stark contrast to the present-day diversity counting more than 2000 species. Here, we describe two new species of ophiuroid, Ophiura tankardi sp. nov. and Ophiodoris niersteinensis sp. nov., from the Lower Oligocene of the Mainz Basin. The species are based on microfossils extracted from the sieving residues of bulk sediment samples from a flush drill in Nierstein, Rhineland-Palatinate. The new species belong to extant genera and add to the poor Oligocene fossil record of the class. Based on present-day distributions, the occurrence of Ophiodoris suggests deep sublittoral to shallow bathyal palaeodepths for the Nierstein area of the Mainz Basin.

A subterminal growth zone at arm tip likely underlies life-long indeterminate growth in brittle stars

BackgroundEchinoderms are a phylum of marine invertebrates with close phylogenetic relationships to chordates. Many members of the phylum Echinodermata are capable of extensive post-traumatic regeneration and life-long indeterminate growth. Different from regeneration, the life-long elongation of the main body axis in adult echinoderms has received little attention. The anatomical location and the nature of the dividing progenitor cells contributing to adults’ growth is unknown.ResultsWe show that the proliferating cells that drive the life-long growth of adult brittle star arms are mostly localized to the subterminal (second from the tip) arm segment. Each of the major anatomical structures contains dividing progenitors. These structures include: the radial nerve, water-vascular canal, and arm coelomic wall. Some of those proliferating progenitor cells are capable of multiple rounds of cell division. Within the nervous system, the progenitor cells were identified as a subset of radial glial cells that do not express Brn1/2/4, a transcription factor with a conserved role in the neuronal fate specification. In addition to characterizing the growth zone and the nature of the precursor cells, we provide a description of the microanatomy of the four distal-most arm segments contrasting the distal with the proximal segments, which are more mature.ConclusionsThe growth of the adult brittle star arms occurs via proliferation of progenitor cells in the distal segments, which are most abundant in the second segment from the tip. At least some of the progenitors are capable of multiple rounds of cell division. Within the nervous system the dividing cells were identified as Brn1/2/4-negative radial glial cells.

Characterization, in-silico, and in-vitro study of a new steroid derivative from Ophiocoma dentata as a potential treatment for COVID-19

The medicinal potential of marine invertebrates' bioactive components that may act as anti-COVID-19 demonstrated promising results. Ophiocoma dentata, which is common in the Red Sea, is one such source. Therefore, this study aimed to isolate a new compound from the brittle star, Ophiocoma dentata, and evaluate its efficacy as anti-COVID-19 in-silico and in-vitro. Standard procedures were followed in order to assess the isolated compound’s preliminary toxicity and anti-inflammatory properties. Computer virtual screening technology through molecular docking and ADMET studies was conducted as well as a new steroid derivative was isolated for the first time, named 5α-cholesta-4(27), 24-dien-3β, 23 β-diol. Investigation of the Anti-Covid-19 activity of the isolated compound using a Plaque reduction assay revealed 95% inhibition at a concentration of 5 ng/µl (12.48 µM). Moreover, this compound showed an IC50 of 11,350 ± 1500 ng/ml against the normal fibroblast cells, indicating its safety. Interestingly, this compound exhibited anti-inflammatory activity with an IC50 of 51.92 ± 0.03 μg/ml compared to a reference drug’s IC50 of 53.64 ± 0.01 μg/ml, indicating that this compound is a potent anti-inflammatory. In silico data have proved that the isolated compound is a promising viral inhibitor against SARS-CoV2 and is thus recommended as a future nature preventive and curative antiviral drug.

New species, redescriptions and new records of deep-sea brittle stars (Echinodermata: Ophiuroidea) from the South China Sea, an integrated morphological and molecular approach

Deep-sea ophiuroids were collected by the manned submersible ‘Shenhaiyongshi’ from the South China Sea at depths of 500–3550 m, in 2017 to 2020. A total of 18 species were identified, including three new species and eight new records, increasing the total number of species known from the South China Sea to 304. Most of the ophiuroids recorded from the South China Sea were found in shallow waters (77.9%) and a few of them occurred only in deep water (20.4%). Three new species are described as Ophiacantha aster sp. nov., Ophiomoeris petalis sp. nov. and Ophiopristis shenhaiyongshii sp. nov. We provide comprehensive descriptions of morphological features, including characteristics of the arm skeletons, and a phylogenetic analysis based on COI and 16S sequences. Overall intraspecific and interspecific genetic distance variations among the families found in this study were 0.5% to 2.47% and 1.16% to 44.16%, respectively, along the South Pacific region to the South China Sea. Our phylogenetic analysis suggested that COI partial genes resolved the interspecies complexity in the class Ophiuroidea better than 16S partial genes. The order Euryalida had low interspecies genetic distance variation within the class Ophiuroidea. The present study suggests a high probability that species of Asteroschema and Gorgonocephalus are more widely spread around the Indo-Pacific region than previously expected.

Fossil Lateral Arm Plates of Stegophiura sladeni (Echinodermata: Ophiuroidea: Ophiurida) from the Middle Pleistocene of Japan

Disarticulated fossil lateral arm plates of brittle stars from the Middle Pleistocene Miyata Formation, Miura, Kanagawa Prefecture, eastern Japan, are described. They are assigned to Stegophiura sladeni on the basis of their microstructural morphology. This is the first description based on disarticulated fossil lateral arm plates of brittle stars from Japan and should encourage further exploration of the Japanese ophiuroid microfossil record.

The complete mitochondrial genome of Asteroschema tubiferum (Ophiuroidea: Euryalida: Asteroschematidae)

We describe the first mitochondrial genome of a brittle star Asteroschema tubiferum Matsumoto 1911 in family Asteroschematidae. The mitogenome was sequenced and assembled using next-generation sequencing technology, and were 16,361 bp in size with 37 genes containing 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and a control region. The phylogenetic tree was constructed based on 13 protein-coding mitochondrial genes of A. tubiferum and 26 species in the phylum Echinodermata by RAxML, which showed that it was mostly related to the species in Family Gorgonocephalidae. These results could provide a novel insight to the phylogeny of Ophiuroidea.

Mitochondrial phylogeny of the brittle star genus Ophioderma

We reconstructed the mitochondrial phylogeny of the species of the brittle star genus Ophioderma, using sequences of the Cytochrome Oxidase I gene (COI) to address four questions: (i) Are the species of Ophioderma described on morphological evidence reflected in mitochondrial genealogy? (ii) Which species separated from which? (iii) When did speciation events occur? (iv) What is the rate of COI evolution in ophiuroids? We found that most of the 22 described species we sampled coincide with monophyletic clusters of COI sequences, but there are exceptions, most notably in the eastern Pacific, in which three undescribed species were indicated. The COI phylogeny lacks resolution in the deeper nodes, but it does show that there are four species pairs, the members of which are found on either side of the central American Isthmus. Two pairs with a genetic distance of ~ 4% between Atlantic and Pacific members were probably split during the final stages of Isthmus completion roughly 3 million years ago. The rate of divergence provided by these pairs allowed the calibration of a relaxed molecular clock. Estimated dates of divergence indicate that the lineages leading to extant species coalesce at times much older than congeneric species in other classes of echinoderms, suggesting that low extinction rates may be one of the reasons that ophiuroids are species-rich. The mean rate of COI substitution in Ophioderma is three times slower than that of echinoids. Conclusions of previous mitochondrial DNA studies of ophiuroids that relied on echinoid calibrations to determine divergence times need to be revised.

Overlooked for over a century: Ophioderma occultum sp. nov. (Echinodermata), a new species of brittle star from the Eastern Pacific

ABSTRACT We describe a new species of ophiodermatid brittle star from the Eastern Pacific: Ophioderma occultum sp. nov. This species has been mistakenly recorded since 1899 as a colour phase of one of its congeners, Ophioderma panamense. However, the integrative use of morphological and molecular data, and comparison with type material of other Eastern Pacific Ophioderma, led to its differentiation as a novel species. Ophioderma occultum sp. nov. is characterised by having radial shields and adoral shields covered with granules, dorsal arm plates divided typically into two pieces, and a particular colour pattern: a dark grey to brown body, and arms with subtle lighter transverse bands and parallel longitudinal white bands over some median and distal segments. Molecular information based on the mitochondrial genes cytochrome oxidase subunit I (COI) and 16S also supported the species’ validity, coinciding with the morphological observations. In particular, the molecular marker 16S had not been used before for species delimitation in this genus and was proven here to be resolutive. In contrast to most species of Ophioderma from the area, Ophioderma occultum sp. nov. shows a restricted distribution to the northern Mexican Pacific (Gulf of California and islas Revillagigedo). This new species is the 10th Ophioderma described from the Eastern Pacific and the 34th worldwide. http://www.zoobank.org/urn:lsid:zoobank.org:pub:A5FFAC55-E5BE-42F6-8371-7B745911F157

Biogeochemistry and trophic structure of a cold seep ecosystem, offshore Krishna-Godavari basin (east coast of India)

Active cold seep sites associated with shallow gas hydrates were recently reported from Krishna-Godavari (K-G) basin, off east coast of India. Benthic fauna including chemosymbiotic bivalves (genera Bathymodiolus, Acharax, Conchocele), polychaetes (genus Sclerolinum), and heterotrophs (gastropods: Provannidae family; squat lobster: Munidopsidae/Galatheidae; Goose barnacle: genus Neolepas; Brittle star: genus Amphiodia) were sampled from the cold seep locations. Here, we present the first δ13C and δ15N data sets of the soft tissues extracted from the organisms along with the sediment pore fluid composition. The isotope ratios of the soft tissues provide a glimpse of the potential food sources for the cold seep organisms and the trophic structure of the ecosystem. The δ13C values suggest the dependence of the Bathymodiolus on methanotrophic symbionts, whereas Acharax, Conchocele, and Sclerolinum show the tell-tale signature of the thiotrophic pathways. In contrast, the heterotrophic benthic fauna shows a wide range of δ13C values, a signature of a variety of carbon sources. The δ15N values of the studied organisms also show a broad range (−1 to +9 ‰) indicating variable food sources as well as variable nitrogen assimilation pathways followed by various symbionts.