Shipworm Research Articles

Membrane vesicles can contribute to cellulose degradation by Teredinibacter turnerae, a cultivable intracellular endosymbiont of shipworms.

Teredinibacter turnerae is a cultivable cellulolytic Gammaproteobacterium (Cellvibrionaceae) that commonly occurs as an intracellular endosymbiont in the gills of wood-eating bivalves of the family Teredinidae (shipworms). The genome of T. turnerae encodes a broad range of enzymes that deconstruct cellulose, hemicellulose, and pectin and contribute to wood (lignocellulose) digestion in the shipworm gut. However, the mechanisms by which T. turnerae secretes lignocellulolytic enzymes are incompletely understood. Here, we show that T. turnerae cultures grown on carboxymethyl cellulose (CMC) produce membrane vesicles (MVs) that include a variety of proteins identified by LC-MS/MS as carbohydrate-active enzymes (CAZymes) with predicted activities against cellulose, hemicellulose, and pectin. Reducing sugar assays and zymography confirm that these MVs exhibit cellulolytic activity, as evidenced by the hydrolysis of CMC. Additionally, these MVs were enriched with TonB-dependent receptors, which are essential to carbohydrate and iron acquisition by free-living bacteria. These observations indicate a potential role for MVs in lignocellulose utilization by T. turnerae in the free-living state, suggest possible mechanisms for host-symbiont interaction, and may be informative for commercial applications such as enzyme production and lignocellulosic biomass conversion.

Species Identification and Attack Patterns Analysis of Marine Borers in Shipwreck Members and Driftwood from the Korean Coast

In this study, we aimed to identify the patterns of perforation damage on shipwreck members excavated from the Korean coast and to estimate the organisms responsible. Two types of marine borers were collected from driftwood collected from Chupo Beach, Shinchang-ri Beach, and Biin Beach, and test piles installed at Shinjindo Beach, and species identification was conducted through visual observation and DNA analysis. The damage patterns of marine borers on the driftwood and test piles were identified and compared with the damage patterns of the shipwreck members. The marine borers found in the driftwood and test piles were identified as <i>Teredo navalis</i> and <i>Limnoria lignorum</i> through DNA analysis and visual observation. <i>T. navalis</i> bored 3-5 mm diameter tunnels in the cross-section of the wood towards the fiber direction, and the damage was severe enough to completely penetrate a 7 cm long piece of wood. The tunnels were lined with calcareous material extruded by <i>T. navalis</i>. In some driftwood, fiber-oriented as well as random-directional tunnels were observed in <i>T. navalis</i> damage scars. In shipwreck members, <i>T. navalis</i> damage was primarily seen in the upper members, which were exposed to seawater and not buried in mud on the shore at the time of excavation, where <i>L. lignorum</i> drilled and gnawed small holes of less than 1 mm diameter in the surface of the wood. Very little evidence of damage by <i>L. lignorum</i> was rarely observed on the topsides of shipwrecks or on the surfaces of members, presumably because the fragile damage was worn away by the movement of currents at sea.

Microbial mutualism in boring clams (Tridacna crocea):Ally shoring of oceans

Ocean ecosystems are highly effective in the recycling of energy and matter. Carbon fixation is almost recycled because net carbon burial in terrestrial systems and export to the ocean via rivers. Heterotrophs efficiently reprocess organic matter because they depend on the energy in organic matter. Withal, heterotrophs cannot use total organic energy because some is shunted into metabolites like ammonium, and under anoxic conditions into reduced substances such as sulphide. These reduced inorganic compounds are used by chemo (litho) autotrophs to obtain energy for inorganic carbon fixation. Host - associated microbial symbionts are critical to the conversion of inorganic carbon into organic biomass (Beinart, R.A., 2019). In the world’s oceans, Boring clams belongs to family Teredinidae, (Shipworms) with habitat of eating wood, assisted by cellulases from the intracellular symbiotic gammaproteobacteria that inhabit their gills. Other shipworms (Kuphus polythalamius) also relying on gill-dwelling gammaproteobacteria for sulphur oxidation (Altamia et al., 2020) and Methane Oxidation. The Symbionts of the gills Teredinibacter turnerae T7901 and similar strains are among the greatest sources of Biosynthetic Gene Clusters (BGCs), with content equivalent to well-known commercial manufacturers such as Streptomyces spp. This implies that shipworms might be a good source of new compounds for drug discovery (Altamia et al., 2020).

Occurrence and Distribution of Shipworms (Mollusca: Bivalvia: Teredinidae) and Two New Records of <i>Bankia</i> species along the Coast of Hokkaido, Japan

Shipworms of the family Teredinidae were collected from driftwood along the coastal areas of Hokkaido between October 2020 and November 2021. Identification of species recorded a total of five species pervaded wooden debris: Teredo navalis Linnaeus, 1758, Lyrodus pedicellatus (Quatrefages, 1849), Bankia setacea (Tryon, 1863), Bankia bipennata (Turton, 1819), and Bankia carinata (Gray, 1827), the latter two were warm-water elements and considered a new record of species discovered from the temperate zone of Hokkaido waters. This suggests the possibility that ocean currents and suitable environmental conditions caused the settlement of these teredinids in driftwood along the vast coastal stretches of Hokkaido. Also, B. bipennata and B. carinata have been most likely distributed along the Sea of Japan and brought accidentally by typhoons from the Kuroshio region and Tsushima and Tsugaru currents to Hokkaido, respectively. Moreover, biogeographic patterns within Teredinidae from other coastal areas in the country and elsewhere were examined from the available literature.

Osmotik Word Level Teredo navalis Linnaeus 1758 in the Mangrove Root Habitat in East Halmahera, Indonesia

This study aims to analyze the osmotic work level and pattern of osmoregulation at mollusc Teredo navalis Linnaeus 1758 in mangrove root habitats from different salinities. Case study was performed with the purposive sampling method. The research data were analyzed descriptively and quantitatively. The sampling technique is based on tidal conditions of seawater. Two locations was designated, namely station I and II in the north and the south respectively. Teredo navalis samples were taken from 2 types of mangrove roots. Analysis of the level of osmotic work using Automatic Micro Osmometer Roebling Type 13/13 DR. Salinity was measured using a refractometer. The results showed that the osmotic level of Teredo navalis in the root habitat of Rhizophora sp. and Avicennia sp. at high and low tide conditions varied, specifically 523 mOsm/l H2O, 123 mOsm/l H2O, and 32 mOsm/l H2O. This varying level of osmotic action results in three patterns of osmoregulation, viz. hyperosmotic, hypoosmotic, and isosmotic. The highest salinity was found in Avicennia sp. mangrove at station II and the lowest in Rhizophora sp. at low tide at station II, with the value was 31‰ and 10‰ respectively. Differences in salinity determine the osmoregulation pattern of Teredo navalis L in different habitats.

Biodegraders of Large Woody Debris Across a Tidal Gradient in an Indonesian Mangrove Ecosystem

There has been limited research on the breakdown, recycling, and flux of carbon from large woody detritus (LWD) in mangrove forests. The breakdown of LWD is caused by guilds of terrestrial and marine biodegrading organisms that degrade wood at a range of rates and efficiencies. Spatial variations in environmental factors within mangroves affect the distribution and community of biodegrading organisms, which, in turn, impacts carbon flow and sequestration. We reveal the role of biodegrading organisms in LWD breakdown and the environmental factors that influence the distribution of biodegrading guilds within a mangrove forest in South East Sulawesi that supports a diversity of mangrove species typical of Indonesian mangrove forests, which constitute 20% of Global mangrove cover. Within the high intertidal regions, terrestrial biodegradation processes dominated upon LWD. After 12 months exposure on the forest floor, experimental wooden panels in these areas remained unchanged in mass and condition. In the low intertidal region, marine wood-boring animals belonging to the family Teredinidae were the dominant biodegraders of LWD, and their activity reduces LWD volume and speeds up the loss of LWD volume. More than 50% of the experimental wooden panels’ weight in these areas was lost after 12 months exposure on the forest floor. Although different biodegrading guilds occupy the same LWD niche, their distribution throughout the mangrove forest is influenced by inundation time. The change of biodegrading guilds within LWD between the terrestrial and the marine organisms was distinct, creating a biodegradation boundary in a distance as narrow as 1 m on the mangrove forest floor. These results are important, as rising sea levels have crucial implications for biodegrading guilds. A full understanding of factors affecting the biodegradation processes of LWD in mangrove forests is critical to accurately assess mangrove carbon stores and the fate of mangrove derived carbon.

PERTUMBUHAN DAN FAKTOR KONDISI T. NAVALIS PADA SALINITAS BERBEDA DI HABITAT ALAMI

T. navalis has high reproducibility and is widely distributed according to physiological tolerance and conditional factors. The purpose of this study was to analyze the growth and condition factors of Teredo navalis Linnaeus 1758 in the mangrove root habitat of Avicennia sp. This type of research is a case study, using the purposive sampling method. Data collection was carried out at two research stations, starting with determining the roots and stems of Avicennia sp mangroves in 70 cm pieces, then observing growth and taking samples. The results showed that the growth of T. navalis in the root habitat of Avicennia sp at treatment S1 (7‰) was 9.96±0.06 gr and the highest at treatment S3 (21‰) was 18.20±0.02 gr. salinity and absolute weight growth of T. navalis with a quadratic pattern with the equation Y = 0.1524x+11.345 R2 = 0.1506, and the optimum point of salinity of 14‰ media can produce maximum absolute weight growth of T.navalis (Y) = 15.33 gr. The results of the calculation of the value of the condition factor (FK) on the relationship between length and weight of T. navalis in the root habitat of Avicennia sp W = 26.29 + 0.39x. Based on the graph of the relationship between length and weight, the value of Y = 00338x2 + 1.8421 + 57,115 and R2 = 0.5834.

Teredo navalis (naval shipworm)

This datasheet on Teredo navalis covers Identity, Overview, Distribution, Dispersal, Diagnosis, Biology & Ecology, Environmental Requirements, Natural Enemies, Impacts, Uses, Prevention/Control, Further Information.

Deterioration of wood exposed to mangrove ecosystem

Deterioration of three types of wood, namely meranti wood (Shorea spp.), mahoni wood (Swietenia mahagoni) and damar wood (Agathis dammara) in underwater exposure in the mangrove ecosystem investigated. The wood soaked for six months, at a depth of 1.5 meters and salinity 7.3. After six months identification of organisms that attack wood is carried out. The types of organisms found attacking wood samples are Teredo navalis and Balanus sp. The types of fungi found include Paecilomyces victoriae, Scytalidium lignicola, Aspergillus sp., Penicillium corylophilum, Aspergillus fumigatus, Biporalis australiensis, Absidia sp, Aspergillus niger and Phytophthora cryptogea.

Evaluation of marine wood boring organism’s attack on wood materials in the Black Sea coastal region

Wood has been used in many areas including the marine environment due to its important properties. However, marine borers cause damage that shortens the service life of wooden materials. Marine borers have a wide distribution and employ different attack mechanisms depending on the geographical region. In this study, wood samples prepared from the Pinus sylvestris L. species were subjected to marine exposure for seven months in the Eastern, Central, and Western Black Sea Regions. Results showed that Teredo navalis marine borer was observed in all three regions. The N, Mg, S, Cl, Ca, Fe, Zn, and Pb content of the samples noticeable increased after the marine trial. According to Fourier transform infrared analysis, carbohydrate content of the samples decreased noticeable, while lignin content increased.

Long-term performance of DMDHEU-treated wood installed in different test set-ups in ground, above ground and in the marine environment

ABSTRACTThe field performance of wood modified with 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU) is reported after outdoor exposure above ground (UC3), in ground (UC4) and in the marine environment (UC5) at six different sites in Europe and Australia. Results from more than seven years field testing with respect to the DMDHEU treatment level, wood species (Scots pine, European beech, spotted gum and slash pine) and climate conditions were evaluated. DMDHEU was shown to significantly improve the biological durability of Scots pine sapwood after exposure under UC3, UC4 and UC5 conditions, which confirmed previous findings on the laboratory scale. The latter was classified as ‘durable to very durable’ (durability class DC1-2). However, DMDHEU modification seemed to be more efficient in Scots pine, slash pine and spotted gum so that higher chemical loadings are required for European beech to reach similar resistance against wood-destroying fungi. Under feeding pressure of Teredo navalis, DMDHEU treatment was graded as ‘durable’.

Sustainability ofTeredo navalis Land Environmental Management Strategies in the Pandemic Era COVID-19

The Wailukum Mangrove Ecosystem requires a community based environmental management strategy. The purpose of this study was to analyze the characteristics of mangrove roots and stems in medium tide zones, the dominance index ofTeredo navalis Land environmental management strategies in the era of the COVID-19 pandemic. This type of research is a case study. The research location is divided into two points, namely in the North and South. Sampling using the line transect method. Root and stem samples were observed using the quadratic method. The results of this study found that there are three types of mangroves that live in the medium tide zone, namelyRhizophora mucronata(Lamk.)Rhizophora apiculata and Rhizophora stylosa Griff. Characteristics of roots and stems have gaps and brittle easily. The dominance index ofTeredo navalis Lon the roots and stems is in the low category with the index range 0.01-0.62. Strategies that need to be used for environmental management of mangroves in Wailukum, East Halmahera Regency, are to open employment opportunities for the community, organize socialization and training of silvofishery systems for workers, make regulations to control community-based mangrove use and monitor violations of mangrove management.

First record of the seagrass-boring shipworm Zachsia sp. (Bivalve: Teredinidae) in natural and transplanted Enhalus acoroides (Hydrocharitaceae) rhizomes in tropical Southwest Pacific

Seagrass ecosystems are under threat worldwide. Seagrass transplantation is one restoration approach which is has been tried with uneven success. While transplantation methods and oceanographic parameters have been investigated in attempts to understand the factors affecting transplant survival rate and seagrass transplantation success, little attention has been paid to the possible impact of pests. We observed borer molluscs in a seagrass Enhalus acoroides both from natural bed and transplant area. This is thought to be the first record from Indonesian waters of these bivalve molluscs of the genus Zachsia, family Teredinidae, the only mollusc genus known to bore into seagrass rhizomes. In a further eleven E. acoroides shoots (average length 10.5cm) we found between one and four calcareous burrows 2mm to 5mm in diameter inside the rhizome. Further research is required to determine the species present and its distribution in Indonesian waters as well as the true ecological impact of Zachsia sp. on seagrasses.

First record of marine wood borer (Mollusca: Teredinidae) Dicyathifer mannii Wright (1866) in Sabah, Malaysia, with detailed measurement metrics

The present study describes the new record of Dicyathifer mannii under the family Teredinidae Rafinesque, 1815. Sampling was conducted in the mangrove area of Kuala Penyu and sample was collected from dead wood debris. The pallets of Dicyathifer is half-conical in shape and 8mm in length. The cone measured 3.9mm in length and 3.6mm in width. The cavity is 1.2mm deep; the curve of the opening on the cone is about 98% of the depth of the cone. Inside the cone cavity, from the center, a ridge with rib-like feature runs down the length of the cavity. Only one species of Dicyathifer is recorded and the present species is the first new record described in Malaysia with some additional measurement metrics for future taxonomic identification purposes.

Bioerosion effects of sea-level rise on the Doge’s Palace water doors in Venice (Italy)

The Doge’s Palace of Venice (Italy) has on its canal-side large doorways closed by old wooden doors. Originally, the thresholds were built above high-water level to avoid direct contact with the water and the resulting damage caused by physical and biological agents. As a result of sea-level rise and land subsidence during the last centuries, the doors are now exposed to tides and to attack by marine wood-boring invertebrates such as shipworms and gribbles. As a consequence, the bottom rails of the doors were recently in need of substantial restoration, which took into consideration new materials and techniques. In this framework, an in situ experiment was undertaken to test the resistance of some selected wood species to woodboring organisms. A quick assessment protocol, based on the EN 275 standard, was set up to quantify bioerosion according to wood species and elevation above sea level. Both European and tropical wood species were tested. The former include Scots Pine, as a reference, and Larch, Cypress and Oak as traditional carpentry materials. The latter include Azobe, Okan, and Bilinga. All the European species showed high susceptibility to woodborer attack, whereas no damage was recorded on the tropical woods. The collected shipworms belonged mostly to Lyrodus pedicellatus and Teredo bartschi with some individuals of Teredo navalis. The only species of gribble found was Limnoria tripunctata. New technical solutions were adopted in the restoration aiming to provide a long service life for the replacements and simplifying the maintenance procedures. Experience, results and solutions are presented.

Morphology and molecular phylogenetic placement of a coastal shipworm (Bactronophorus thoracites (Gould, 1862), Teredinidae) from Peninsular Malaysia

The wood-boring shipworm, Bactronophorus thoracites (Teredinidae), is the only species in the genus Bactronophorus, with wide distribution in the Indo-West Pacific biogeographic region. Besides rendering important ecosystem services such as in decaying wood and participating in C fluxes in mangroves, to several ethnic groups in Southeast Asia, this mollusk is a highly nutritious delicacy when eaten raw. There are near 20 shipworm species reported in Malaysian waters, however, in-depth studies have not been conducted on any of these species. Here, we characterized B. thoracites from a mangrove environment on the west coast of Peninsular Malaysia. This bivalve is distinguished by its non-segmented pallet, composed of a basal cup with a dagger-like extension. Molecular phylogenetic analyses using 16S gene sequences from six different species (family Teredinidae) including B. thoracites, revealed a monophyletic relationship. On the contrary, combined datasets of 18S and 28S rRNA gene sequences from 12 different species (family Teredinidae) suggested a paraphyletic relationship; B. thoracites appeared to be a sister to Neoteredo reynei. Using the DNA barcode COI, B. thoracites is clearly separated from other teredinids, albeit with moderate bootstrap support. Molecular dating analysis speculated the divergence time between B. thoracites and N. reynei was the Early Cretaceous period. We provide novel DNA sequences for B. thoracites, which could be useful for species identity validation and molecular taxonomical studies.

Morphologic characteristics and population density of Teredo Navalis L in mangrove forest area, Wailukum East Halmahera Regency

This study aimed to analyze the population density and distribution patterns of Teredo Navalis L in the mangrove forest area of Wailukum Maba, East Halmahera Regency. A survey method with deskriptive analysis used in this research, while the reseacrh location was determined using a purposive method. The research location is 100 meters long and 50 meters wide, making it 5,000 m2. The research location was divided into 4 stations. Station I in the north, station II at the center, station III in the east and station IV in the west. At each station, five transect lines were made using a rope and 5 plots were placed alternately with a size of 10x10 meters. The results showed that there were three morphological characteristics of T. navalis L. These carakteristics divided in mangrove logs based on body measurements 0f 60 cm long, 30 cm long and 15 cm long. The population density of T. navalis L at the four stations varied between 1-2 ind / m2. the highest population density was measured at station II (2 ind/m2) and the lowest was measured at station III (1 ind/m2).

Tamilokus mabinia, a new, anatomically divergent genus and species of wood-boring bivalve from the Philippines.

Here we describe an anatomically divergent wood-boring bivalve belonging to the family Teredinidae. Specimens were collected off the coast of Mabini, Batangas, Philippines, in February 2018, from sunken driftwood at a depth of less than 2 m. A combination of characteristics differentiates these specimens from members of previously named teredinid genera and species. Most notable among these include: an enlarged cephalic hood which extends across the posterior slope of the shell valves and integrates into the posterior adductor muscle; a unique structure, which we term the ‘cephalic collar’, formed by protruding folds of the mantle immediately ventral to the foot and extending past the posterior margin of the valves; a large globular stomach located entirely posterior to the posterior adductor muscle and extending substantially beyond the posterior gape of the valves; an elongate crystalline style and style sac extending from the base of the foot, past the posterior adductor muscle, to the posteriorly located stomach; calcareous pallets distinct from those of described genera; a prominently flared mantle collar which extends midway along the stalk of the pallets; and, separated siphons that bear a pigmented pinstripe pattern with highly elaborate compound papillae on the incurrent siphon aperture. We used Micro-Computed Tomography (Micro-CT) to build a virtual 3D anatomical model of this organism, confirming the spatial arrangement of the structures described above. Phylogenetic analysis of the small (18S) and large (28S) nuclear rRNA gene sequences, place this bivalve within the Teredindae on a branch well differentiated from previously named genera and species. We propose the new genus and species Tamilokus mabinia to accommodate these organisms, raising the total number of genera in this economically and environmentally important family to 17. This study demonstrates the efficacy of Micro-CT for anatomical description of a systematically challenging group of bivalves whose highly derived body plans are differentiated predominantly by soft tissue adaptations rather than features of calcareous hard-parts.

The occurrence of boring bivalve (Genus: Zachsia), in a tropical seagrass meadow in Gaya Island (Sabah, Malaysia) and its possible ecological implications


 Shipworms (family Teredinidae) are specialized bivalves that bore into the submerged wooden structures and mangrove trees, except genus Zachsia which is associated with seagrass rhizome. However, only one species has been described, located in Russian, Korean and Japanese waters and associated only with genera Phyllospadix and Zostera. Potentially wider distributions and even new species within this group have not been reported from another bioregion. Given the potential impacts on seagrass health, it is important to ascertain if the distribution of Zachsia extends across other climatic regions and seagrass species. In response, a study was conducted in a seagrass meadow at Gaya Island (Sabah, Malaysia). A total of 900 seagrass shoots were randomly excavated from a mixed seagrass bed of Enhalus acoroides, Cymodocea rotundata and C. serrulata. It was found that Zachsia sp. was present within the rhizomes of E. acoroides and C. rotundata, with an occupancy of around 12% occupancy (n=100) and 1% (n=400), respectively. A post-mortem examination indicated that the bivalve appeared to have ingested most of the rhizome’s internal tissues, leaving behind a calcareous hollow tube. Furthermore, this apparent infestation appeared to significantly reduce shoot growth by around 70% from 0.738±0.036 to 0.220±0.038 cm day-1. This finding may be significant, as it suggests, for the first time, that the rhizome parasitism is another possible vector in controlling seagrass growth and mortality. Further investigations are required to determine if this boring bivalve is indeed a new species, its distribution in other tropical areas and its role in the ecosystem.

A new genus and species of deep-sea wood-boring shipworm (Bivalvia: Teredinidae) Nivanteredo coronata n. sp. from the Southwest Pacific

ABSTRACTNivanteredo gen. nov. coronata sp., a new genus and species from the wood-boring bivalve family Teredinidae, is described. Multiple specimens were collected off the coasts of Vanuatu, the Solomon Islands and Papua New Guinea, between October 2004 and August 2014, from both sunken driftwood and deployed wooden panels at depths of 240–773 m. A combination of features identify these specimens as both a new genus and species, including: unique calcareous pallets distinct from those of all other previous described genera, featuring a central stalk that runs almost the entire length of the blade and a disk shaped periostracal awning adorning the proximal pallet; an elongated mantle collar, extending from the base of the siphons to the mid-stalk of the pallets; a distinctive and elongated auricle on the dorsal shell valve; a complex caecum (wood-storing organ) featuring a highly coiled typhlosole, which ranks as one of the largest relative to total body length among the family. Larval settlement on wooden panels placed at 441 m represents the deepest distribution range of any known teredinid, which were previously thought to be restricted to waters above 200 m. The discovery of Nivanteredo coronata, recruiting at depths more than twice those previously recorded for tereinids, raises the possibility of a hidden diversity in other deep-sea locations and suggests that previous sampling, which has largely been limited to shallow coastal waters, has skewed our understanding on the biogeography and distribution of this family. To aid future identification and systematics of this complex family, we produced a revised and updated appendix of both internal and external characters across the Teredinidae, including the new genus Nivanteredo.http://zoobank.org/urn:lsid:zoobank.org:pub:24216C86-CCB0-4B27-8FE2-89338969E32E