Search

Subsistence and small-scale aquaculture are important economic and livelihood activities in developing countries including the Philippines. Community-based aquaculture of the sea cucumber (sandfish, Holothuria scabra) has been promoted as a sustainable supplemental livelihood activity among rural coastal communities, however, uptake remains poor and the economic viability of communal sea cucumber ranching has yet to be demonstrated. This study assessed the potential of sandfish farming as a supplemental economic activity for established small-scale grouper (Epinephelus coioides) farmers in Bolinao, northwestern Philippines, on the assumption that the adoption of sandfish culture may be more successful when attempted by established aquaculture farmers. The average growth rate of sea cucumbers reared in the pens without groupers was highest at 2.0 [+ or -] 0.4 g [day.sup.-1] during the first 50 days of rearing. By 141 days, sandfish reared without grouper attained an average weight of 234.7 [+ or -] 2.2 g. The highest growth rate of sandfish reared with groupers was recorded at 4.2 [+ or -] 1.8 g [day.sup.-1] after 19 days of rearing in the coculture pens whereas the lowest growth rate (-0.73 [+ or -] 0.1 g day- 1) was recorded by day 128. Additionally, the growth performance and survival of groupers reared with sandfish were high. From an initial average weight of 141.3 [+ or -] 35.2 g, groupers attained an average weight of 340 [+ or -] 27.8 g and 393.8 [+ or -] 17.8 g after 102 and 163 days of rearing, respectively in the grow-out pens. Farmers generated an estimated income of PHP 7,200 and PHP 29,015 from the sale of dried sea cucumbers and live groupers, respectively. Results indicate that the adoption rate, economic viability, and sustainability of sandfish mariculture may increase when technology is transferred to farmers already engaged in aquaculture. More broadly, the integration of sandfish culture with that of fish and other culture species, such as molluscs, utilizes the ability of sea cucumbers to remediate nutrientrich sediments, improving sustainability. KEY WORDS: Holothuria scabra, sea cucumber, sandfish, grouper, coculture, small- scale aquaculture, INTRODUCTION Aquaculture is the fastest-growing global food production sector achieving an annual growth rate of 5.3% between 2001 and 2018 and contributing one-third of global food fish production. Worldwide, 70%-80% [...]

Ever since the Taiwanese government introduced the giant freshwater shrimp (GFS) (Macrobrachium rosenbergii) to Saint Lucia in the 1980s, its production has increased significantly. This production although has contributed significantly to the well-being of local farmers and the gross domestic product of Saint Lucia, its productivity is however threatened by challenges such as scarcity and high cost of live feed (nauplii from Anemia sp.), poor funding, insufficient and substandard hatcheries, poor infrastructures, high mortality rate of postlarvae due to adverse climate, diseases, and knowledge gap between researchers and local farmers (inadequate extension services). Among these challenges, the total reliance on scarce and expensive live feeds (nauplii from Anemia sp.) is the most crucial . Therefore increasing production costs is of the utmost importance and requires urgent attention. Although it would not be possible to completely substitute nauplii, combining it with other inexpensive, readily accessible, and locally sourced feed components is paramount. As evident in postlarvae-producing countries, alternative diets have been compounded and fed in place of nauplii to lower production costs without any negative impact on the general performance of GFS postlarvae being recorded. This could be adopted and replicated in the production of GFS postlarvae in Saint Lucia because most of the ingredients such as powdered fishmeal, duckweed, moringa leaf, freshwater daphnia and rotifers, and microalgae are readily available and accessible within the country. KEY WORDS: Aquaculture, Anemia, Macrobrachium rosenbergii, feed, production, shrimp, INTRODUCTION The growth of aquaculture in the Caribbean has been characterized as slow but steady since the introduction of tilapia culture in the early 1960s (Largo et al. 2020). More [...]

Antilipopolysaecharide factors (ALF) are antimicrobial peptides in the humoral defense mechanism in shrimps, with broad activity against bacteria, viruses, and fungi. Several ALF and their isoforms have been reported in decapod crustaceans, showing structural and functional differences. This work describes the Litopenaeus vannamei antilipopolysaecharide factor 5. initially found in a hepatopancreatic transcriptomic database. The LvALF5 gDNA sequence is 1,619 bp, with a complete mRNA sequence of 934 bp. The ORF encodes a 124 amino acids sequence, including a 26 amino acids signal peptide and 98 amino acids mature peptide, highly similar to the Litopenaeus stylirostris ALF peptide sequence (96%). This peptide shows main differences in the LPS-binding domain, having only 2 positive amino acids conserved. The evolutionary analysis shows that LvALF5 is in cluster 2, which indicates that structurally it has characteristics of the other white shrimp isoforms. LrALF5 is highly expressed in healthy shrimp hemocytes, 20-fold more than in other tissues. It is up-regulated during bacterial and viral challenges. Inhibition experiments using a recombinant LrALF5 show a more efficient antibacterial activity against Vibrio parahaemolytieus than Staphylococcus aureus bacteria strains. KEY WORDS: Litopenaeus vannamei, antimicrobial peptides, gene expression, Vibrio parahaemolvticus, WSSV, antibacterial activity, INTRODUCTION The Pacific white shrimp Litopenaeus vannamei is one of the most important cultured species in the aquaculture industry. Despite being a very profitable commercial product reaching 5.8 million tonnes [...]

Incirrate octopodes are the only cephalopods that exhibit transient epidermal structures called Kolliker's organs (KO) in the early development stages. This work describes for the first time the histological formation process of these organs during embryonic development and of the paralarva of Octopus huhbsorum Berry, 1953, as well as their morphological characteristics. Egg masses were collected in the Gulf of California and the species was identified by molecular analysis. The histological formation of KO starts when the funnel is fully developed and ends when the embryo is ready for hatching. Differences were observed compared with the only complete histological description of KO currently available. In O. huhbsorum, the basal membrane wraps the basal and lateral cells until the KO erupts, and the cell conformation of KO (binding with muscle cells) is completed when the mantle covers the ventral margin of the funnel and chromatophores are visible. The KO of O. huhbsorum are of intermediate size and show a higher density compared with other species, especially in the arms. The cellular degradation of KO is reported here for the first time; KO disappears within 48 h posthatching, contrary to observations reported for other species in which these organs last more than 30 days, even before settlement. It is concluded that in this species, KO probably facilitate hatching or are an evolutionary reminiscence, and it is ruled out that they facilitate buoyancy before settlement. KEY WORDS: cephalopods, embryo, paralarvae, epidermis, octopus, INTRODUCTION Particularly in octopuses, the external morphology of some species varies markedly during early development (embryo, paralarva, and juvenile), including the number of suckers per arm, arm length, and chromatophore [...]

Although populations of the eastern oyster Crassostreu Virginia! have been the focus of numerous studies for more than a century, less is known about the coastal lagoon populations such as those of Delaware's Inland Bays. Increasingly, oyster restoration projects in coastal regions are incorporating oyster stocking programs to restore areas with reduced oyster populations to capture both economic benefits and ecosystem services provided by healthy reefs. In Delaware, the Center for the Inland Bays conducted a volunteer oyster gardening program lasting 20 y employing disease-resistant hatchery spat. Using a suite of microsatellite loci, we examined the genetic profiles of locally recruited inland bay oysters, nearby wild Delaware Bay oysters, and the disease-resistant hatchery strain to evaluate the potential impact of the gardening program. The Inland Bay samples showed genetic profiles similar to the wild Delaware Bay population, suggesting an extant resident population providing a consistent larval supply, potentially clouding the contribution of the hatchery-spawned gardened oysters. KEY WORDS: Crassostreu Virginia/, Delaware Inland Bays, genetic diversity, INTRODUCTION The current dogma for the conservation of biodiversity within environmental policy arose after centuries of scientific observations documenting the landscape impacts of exploitation, habitat degradation, and increasing human activity [...]

Pearl culture in Fiji relies on a supply of pearl oysters obtained through the strategic deployment of spat collectors. Although the design and deployment of spat collectors aim to maximize the recruitment of pearl oysters (Pinctada and Pterin spp.), this activity incidentally captures many other bivalves as bycatch. This study explored whether tropical rock oysters (specifically Magallana bilineata and Saecostrea spp.) were present and sufficiently abundant as bycatch from pearl oyster spat collectors, to support additional commercial opportunities. The results showed that the absolute (0.7 [+ or -] 2.1 spat collector-1) and proportional (2.9% of all bivalves) abundance of these taxa was very low, which would limit oyster harvest in meaningful quantities. Although the prospect of creating additional revenue streams from bycatch could be seen as an incentive to on-grow and sell tropical rock oysters despite their low abundance, it is argued that greater benefit would come from prioritizing activities related to pearl oysters and associated downstream products such as mabe pearl, shellcraft, and pearl-meat production. Ultimately, existing spat collection activities within the cultured pearl sector did not have the anticipated potential to support supplemental aquaculture of tropical rock oysters. KEY WORDS: Fiji, spat collection, fouling, bycatch, tropical rock oyster, Saecostrea, Magallana bilineata, INTRODUCTION Tropical rock oysters are excellent candidates for aquaculture (Angell 1986, Nowland et al. 2020). They are consumed almost everywhere they occur (M unro 1994, Kinch et al. 2019a, Simard [...]

Pinlo abalone populations in the Salish Sea, WA have declined precipitously in the last several decades and have not recovered despite fishery closure in 1994. The Puget Sound Restoration Fund, in collaboration with state and federal agencies, has been outplanting juvenile pinto abalone at sites in the San Juan Archipelago, and some sites are much more successful than others despite similar physical characteristics. The sites, however, likely differ in oceanic parameters, such as temperature, salinity, and pH, which are in turn changing as the climate of the Earth is changing. The purpose of this study was to investigate the effects of temperature fluctuation and pC[O.sub.2] levels on the survival, growth, and oxygen consumption of juvenile pinto abalone. In a fully crossed experiment, juvenile pinto abalone were held at either currently ambient (400 ppm) or elevated (1,200 ppm) pC[O.sub.2] and at constant (10[degrees]C) or fluctuating (10 [right arrow] 14 [right arrow] 10[degrees]C) temperature. Survival was monitored weekly and growth was measured after 4 wk. In a second experiment, abalone were held in the same crossed pC[O.sub.2] and temperature treatments, and oxygen consumption was measured. High pC[O.sub.2] and fluctuating temperature both significantly decreased abalone survival. Abalone growth was not affected by pC[O.sub.2] level (temperature could not be analyzed due to very poor survival in the fluctuating temperature treatments). In addition, there was an interaction between fluctuating temperature and pC[O.sub.2] level on abalone oxygen consumption. Abalone in the constant temperature treatment had higher oxygen consumption when exposed to elevated pCO,; however, this pattern was not observed in the fluctuating temperature treatment. The results of this experiment indicate that outplant sites with minimal temperature fluctuation and lower pC[O.sub.2] levels could lead to improvements in outplanting success of juvenile pinto abalone. KEY WORDS: Haliotis kamtschatkana kamtschatkana. abalone restoration, outplanting, climate change, INTRODUCTION Pinto abalone (Haliotis kamtschatkana kamtschatkana Jonas) is the only abalone species found in the northeastern Pacific Ocean and it has cultural, economic, and ecological importance to both indigenous and [...]

Disseminated neoplasia (DN) is a form of cancer in bivalve molluscs that can be transmissible between individuals and in some cases across species. Neoplastic cells are highly proliferative, and infection is usually lethal. Commercially valuable bivalve species (mussels, cockles, softshell clams, and oysters) are affected by outbreaks of DN, making disease diagnosis and mitigation an important issue in ecological restoration efforts and aquaculture. Basket cockles (Clinocardiwn nuttallii) are native to the North American Pacific coast from California to Alaska. Recent concern from some Coast Salish Tribes regarding an observed long-term decline in basket cockle populations in Puget Sound. WA has increased interest in monitoring efforts and subsequent collection for aquarium-reared broodstock. Disseminated neoplasia was detected in Puget Sound basket cockle populations, delaying aquaculture efforts so that potential broodstock could be assessed for the presence of DN. This study details a minimally invasive, inexpensive, nonlethal method for high-throughput screening for DN in adult basket cockles. The hemolymph smear screening method to diagnose DN in C. nuttallii can be applied at field sites at low financial cost. Results of the hemolymph smear technique were validated against whole tissue histology, the standard method for DN diagnosis. Due to the similar cellular morphologies of DN in different bivalve species, it is proposed that hemolymph histology can likely be applied for diagnosing DN in other bivalves. KEY WORDS: disseminated neoplasia, Cltnocardiwn nuttallii, disease screening, tissue histology, basket cockle, INTRODUCTION Diverse bivalve species worldwide are susceptible to disseminated neoplasia (DN), a disease in which cancerous cells proliferate in the hemolymph--the blood-like fluid in molluscs containing a mixture of nutrients, [...]

Severe declines in commercial and recreational fisheries of the bay scallop, Argopecten irradians, and the success of the Chinese industry have led to increased interest in aquaculture in the United States. In recent years, the Chinese industry has sought to improve production through marker-assisted selection and has identified several candidates that may be predictive of performance. We explored the utility of a subset of these markers [size- related quantitative trait loci (QTL) marked by ten microsatellites and four single nucleotide polymorphisms (SNP) in the myostatin gene] to improve the growth performance of bay scallops in North Carolina (NC) using quantitative genetics and marker- assisted selection. Mature scallops were collected from three wild populations in the fall of 2019 in Topsail Sound, Core Sound, and Bogue Sound. The wild scallops were brought back to the University of North Carolina Wilmington (UNCW) Shellfish Research Hatchery (SRH), and each group was spawned separately. The wild scallops were genotyped at the 14 markers to confirm their presence in NC populations. The 2019 offspring lines were genotyped, and growth monitored to evaluate the association of the microsatellite and myostatin SNP genetic markers with growth performance. Except for a single marker in a single line, no association of the markers with growth metrics was observed. Consequently, in the fall of 2020, performance-based selection was implemented by sorting 2019 lines into 'Big' and 'Little' groups based on shell height and spawned separately. Evaluation of microsatellite and SNP genetic markers in broodstock scallops revealed significant genetic differences among the size groups; however, no consistent significant association between the genetic markers and performance was observed in broodstock scallops. Offspring of the size-sorted groups were deployed to three NC aquaculture farms in April 2021 and monitored for 7 mo. Overall survival ranged from 3% on Farm B (terminated in August 2021) to 37% on Farm A and was 16% at UNCW (terminated in November 2021). Offspring of the 'Little' broodstock survived better at UNCW (19% versus 14%) but there was no difference at the other two sites. Growth also differed among sites. At UNCW there were no significant differences in any of the growth metrics assessed between the offspring of the 'Big' and 'Little' broodstock; however, there were significant differences between the offspring on Farm A. The 'Little' line was significantly smaller than the 'Big' which was similar in size to the scallops at UNCW except for shell width and adductor muscle weight. The results of this study suggest the genetic markers identified for selective breeding in Chinese bay scallops are not applicable for predicting superior performance in NC bay scallops. KEY WORDS: Argopecten irradians, bay scallop, aquaculture, genetics, growth. North Carolina, INTRODUCTION The bay scallop, Argopecten irradians (Lamarck 1819), is an epibenthic bivalve that occurs in sheltered bays and sounds along the Atlantic and Gulf coasts of the United States. Massachusetts, [...]

Blood cockle sampling and water quality monitoring were conducted monthly between September 2011 and June 2013 at four blood cockle aquaculture farms situated along the Selangor coast, of Malaysia. Histological observations of the gonads were performed to identify male and female blood cockles. The maturation of gonadal tissue was evaluated, and the relationship between the maturation status of blood cockles and water quality factors, such as salinity and chlorophyll a concentration, was examined at each station. Mature and spawning male cockles were present year-round at all stations except at Station C, where males were more susceptible to the influence of the estuary. Females exhibited a distinct seasonal change in gonadal tissue compared with males, with a higher proportion of spent-stage individuals during the dry season. In addition, the number of immature individuals, for which it was difficult to distinguish between males and females, increased during that period. These results showed that spawning activity on the Selangor coast is more prominent during the rainy season and less pronounced during the dry season. The relationship between salinity, chlorophyll a concentration, and the gonadal tissue maturation stage of the cockle was identified. These findings reveal that sexual maturation progressed in brackish water with a salinity of approximately 28 in both males and females. As salinity decreased to less than 25, the proportion of immature and spent-stage individuals that released sperm or eggs increased. Additionally, immature individuals' percentage increased when chlorophyll a concentration was low ( KEY WORDS: sexual maturation, blood cockle, Tegillarca granosa, Selangor, Malaysia, INTRODUCTION Also known as Anadara granosa (Linnaeus, 1758), Tegillarca granosa (Linnaeus, 1758) is a blood cockle. It is morphologically defined by approximately 18 ribs and numerous nodules on the shell [...]

White abalone (Haliotis sorenseni) are an endangered species found along the southern California and Baja, Mexico coast. To recover the species population, conservation aquaculture is currently used to culture the species for out planting to wild habitat. Withering syndrome, caused by the bacterium Candidatus xenohaliotis californiensis attacking the digestive tract is known to impact the survivorship of the species in captivity. An experiment to test the effectiveness of probiotic Bacillus Hcheniformis in reducing the impact of the disease on white abalone exposed to infected red abalone was conducted. During this study, unexpected shell loss was observed in both the red and white abalone. Shell loss had been observed in other facilities, but the rate of shell loss in this experiment was on a larger scale than previously observed (43% in white abalone and 52% in red abalone). There was no significant difference detected in shell loss rate between experimental disease treatments indicating that the probiotic was not responsible for the shell loss. The initial study was abandoned, and two subsequent studies were conducted to better understand the cause of the shell loss. Shell loss syndrome was investigated to determine if the shell loss was infectious, but the shell loss could not be replicated via exposure to symptomatic animals. This observational study discusses other possible causes of shell loss syndrome including water quality, shell irritants, and other stressors. Although no specific cause of shell loss could be determined it is possible that a combination of stressors on the abalone in this experiment could have caused shell loss. This investigation details the rate and progression of shell loss, the impacts of shell loss on abalone health, and the survival rates of abalone with shell loss syndrome. KEY WORDS: shell loss, white abalone, red abalone, bacterial infection, hydrogen sulfide, harmful algal bloom, INTRODUCTION Most marine molluscs have external shells that function largely to protect and support the bodies of the animals within. Given the importance of this common molluscan trait, observations of [...]

Since October 2016, the endangered fan mussel. Pinna nohilis, has suffered mass mortality episodes throughout the Mediterranean Sea caused by a haplosporidian parasite, Haplosporidium pinnae, which could eventually lead to the extinction of the species. In response to this crisis, rescue projects have emerged in several Mediterranean countries and tend to focus on reintroducing individuals to their natural environment. To ensure that the reintroduclion of healthy P. nohilis is successful, it is imperative that the parasite is no longer present in the natural habitat and that there is no risk of a new infection. Instances in which molluscs have been infected by haplosporidian parasites, in habitats where the host species was absent for a couple of years, have been reported, suggesting that haplosporidian parasites can persist in the ecosystem for at least 2 y. We hypothesized that H. pinnae could survive without P. nohilis, using another host and without causing similar mortality. This study aimed to test if other bivalve species living in the same environment as P. nohilis could act as potential reservoirs for the parasite. The presence of the parasite was investigated using haplosporidian PCR barcoding with specific primers in 15 species of marine bivalves collected at eight sites spread along the Southern French Mediterranean coast. Out of 116 specimens, successful PCR amplifications were obtained in seven individuals of Cerastodernw glaucum but the amplified sequences were not attributed to H. pinnae, and the species remains to be identified. This study did not succeed in detecting a species of mollusc that could potentially maintain the parasite responsible for fan mussel mortality in the environment, but docs provide initial results that significantly enhance our understanding of the ongoing pandemic that is currently devastating P. nohilis populations. KEY WORDS: Haplosporidium pinnae. Pinna nohilis, fan mussel, Mediterranean Sea, bivalve, parasite, intermediate host, Haplosporidia, INTRODUCTION The fan mussel, Pinna nohilis (Linnaeus 1758). is endemic to the Mediterranean Sea and one of the largest bivalves in the world, as its shell can reach up to [...]

Understanding population history and genetic connectivity is important for assessing the long-term viability of populations. The Atlantic surfclam (Spisula solidissima) has historically been subdivided into two subspecies: lesser-known S.s. simitis in the South Atlantic Bight and Gulf of Mexico, and commercially important S.s. solidissima mostly north of Cape Hatteras. Novel populations of the 'southern' S.s. similis subspecies were previously identified far north of their historical range limit. Here, to test a hypothesis of recency and isolation in the North, population samples from Southern New England S..s. similis were compared for the first time to a population sample from Georgia, as well as to S.s. solidissima. Population structure and demographic history were inferred using genetic variation at a combination of microsatellite, mtDNA, and nuclear intron loci. The Southern New England populations of S.s. similis had slightly lower nuclear DNA diversity than in Georgia. Genetic differentiation between Massachusetts and Georgia S.s. similis was weak and only significant for microsatellite markers. Consistent with weak differentiation, coalescent modeling of nuclear sequence variation indicated high levels of gene flow. All S.s. similis populations had extremely low mtDNA diversity, with only two mitochondrial cytochrome oxidase I haplotypes found in contrast to 15 haplotypes in S.s. solidissima. Collectively, the population genetic patterns are more parsimoniously explained by the northern S.s. similis populations originating from a postglacial expansion rather than recent colonization. KEY WORDS: Spisula solidissima, population structure, gene flow, marine phylogeography, mitochondrial DNA, COI, intron, microsatellites, coalescent model, demographic history, INTRODUCTION It is valuable to assess the population history and genetic connectivity of populations to assess their long-term viability and threat of extinction (Allendorf & Luikart 2009, Hellberg 2009, Nance [...]

Fisheries that target sedentary shellfish present several challenges for deriving management reference points. Stock-recruit relationships often function at a relatively large spatial scale, with planktonic dispersal of eggs and larvae connecting discrete settlement areas, but postsettlement demographics are heterogeneous among local settlement areas. Another challenge is that information on age composition is not available for many invertebrates. Case studies of sedentary shellfish fisheries demonstrate a series of methods for estimating reference points. Biomass dynamics models may be an option for some data-limited fisheries, but inferences of metapopulation productivity can be confounded by serial depletion, so fishery and survey data should be explored for spatial patterns. Yield-per-recruit and eggs-per- recruit models can be size-based and spatially stratified. Demographic models of the full life cycle can integrate regional recruitment processes and postrecruitment processes at smaller spatial scales. Although metapopulation dynamics and spatial heterogeneity in postsettlement demographics can be accounted for in reference points, achieving the optimum yield of sedentary shellfish is largely conditional on managing spatial fishing patterns. KEY WORDS: benthic, shellfish, fisheries, management, reference points, INTRODUCTION Shellfish fisheries are valuable and substantially contribute to global fishery production (e.g., 25% of global consumption, FAO 2022). Worldwide landings of bivalves gradually increased from 0.8 million tons in [...]

October 29, 1933-September 24, 2022 The National Shellfisheries Association (NSA) lost Ken Chew, one of the true pioneers in shellfish biology and aquaculture, on September 24, 2022. What follows here [...]

The lanternfish family Myctophidae is one of the most speciose lineages of mesopelagic fish species. It is composed of 34 genera, currently comprising over 250 valid species (Fricke et al., [...]

Relationships between form and function have been the subject of many morphological and evolutionary studies (e.g., Dean et al., 2007; Kolmann et al., 2014). For example, elongated rostra have appeared [...]

The sharpspine skate (Okamejei acutispina), a small skate belonging to the family Rajidae, inhabits sandy-muddy bottoms at depths of 20-175 m in the Northwest Pacific Ocean, from the waters of [...]

The natural mortality rate (M) is a crucial population parameter, particularly for managing exploited stocks. Empirical methods developed to estimate M generally depend on individual growth and habitat temperature. The gnomonicstage method, in contrast, allows estimates of M for all life-history stages considered of a species: the challenge is how to derive a single M value for use in further fisheries analyses. In this study, a single M value was derived using the gnomonic method for the blue lobster (Panulirus afflatus) fished off the southern Gulf of California. The estimated M value relied on existing biological data for the exploited phase of the species for which there is only scarce information. Because in the gnomonic method, M relates to fecundity, a sensitivity analysis of yield-per-recruit to different fecundity values was performed. The results have practical implications for ecology and stock assessment of the blue spiny lobster and other fished resources. KEY WORDS: gnomonic M, Panulirus inflatus, YPR sensitivity analysis, INTRODUCTION The natural mortality rate (M) is among the most important parameters for the management of exploited stocks (Maunder et al. 2023). M is related to the productivity of the [...]

The global demand for crabs, coupled with increasing threats to natural populations, creates the need to investigate captive breeding programs. To achieve this, it is crucial to acquire a comprehensive understanding of key aspects of their life cycle. This study represents the early comprehensive characterization of the red mangrove crab, Ucides occidentalis. Furthermore, leveraging epifluorescent microscopy, we examined the effect of six distinct microaigae diets on the progression of larval stages and their subsequent survival. Embryonic development in U. occidentalis unfolded over a period of 14 days, systematically detailed across eight distinct phases, each marked by the progressive emergence of the embryo and its associated appendages. Notably, an increase in the heart rate was registered just prior to spawning. Following spawning, a brief period of 10-15 min elapsed before the embryos successfully ruptured the chorion. Larval development underwent segmentation into five zoeal stages (zI-zV), spanning a 15-day duration, with an equivalent temporal period encompassing the megalopal stage until the attainment of the first juvenile crablet. Each transition between stages was heralded by a molting event. Despite our observations confirming the ingestion and digestion of the assessed microaigae, it became evident that diet supplementation with rotifers and brine shrimp is essential to optimize molting periods and, consequently, enhance survival rates. Specifically, diatoms Chaetoceros gracilis and Chaetoceros muelleri were ingested and digested up to the zoea V stage. In contrast, the microaigae Tetrase/mis maculala and Rhodomonas salina, while undergoing ingestion and digestion, were only able to sustain larvae until the zoea III stage. The outcomes of our research affirm the viability of U. occidentalis crablet production within a laboratory setting, thereby offering the potential inclusion of this species as a valuable aquaculture product. This endeavor holds the promise of contributing to the conservation and enhancement of wild U. occidentalis populations. KEY WORDS: Ucides occidentalis, embryonic development, crab feeding, early crab description, epiffuorescence, crab production, INTRODUCTION The species Ucides occidentalis (Ortmann, 1987), commonly referred to as the red mangrove crab, exhibits a geographical distribution that encompasses the tropical West Pacific region. Specifically, this species is [...]

The eastern oyster (Crassostrea virginica) is an ecologically and economically important species that provides invaluable services for coastal communities. The oyster industry has a long history and tradition in the U.S. Gulf Coast states, but this fishery has declined dramatically in recent years following Hurricane Katrina, the Deepwater Horizon oil spill, and freshwater flooding events. Mississippi was once known as the 'seafood capital of the world,' but no commercial harvest from Mississippi oyster reefs has occurred since the 2018-2019 season. A review of the Mississippi oyster fishery was conducted to characterize historical conditions relative to a sustainable resource in this region, and how the oyster resource has changed over time due to environmental factors and nonbiological events. Since state management of the oyster fishery began in 1902, oyster landings have fluctuated dramatically over time due to complex interactions between man-made and natural disasters, variability in salinity regimes, and alterations in management authority and approaches. Prior to 2010, Mississippi oyster populations eventually recovered from mass mortality events due to improved environmental conditions coupled with large cultch planting efforts. Significant resources have been invested to restore wild oyster populations in the northern Gulf of Mexico, but these efforts have faced many obstacles, and the baseline to assess restoration progress is not well defined. Present-day challenges hindering oyster recovery efforts in Mississippi were also examined to improve understanding of key abiotic and biotic factors that influence oyster reef health and resilience. At present, adult populations are severely diminished and appear to be more recruitment-limited than during previous historical collapses. Climate change-related precipitation events in the past decade have altered water quality in the Mississippi Sound and have further hampered critical early life history recruitment processes, as well as overall reef resilience. Successful restoration and persistence of sustainable oyster reefs in Mississippi under current and future conditions will require substantial investment in management practices that provide suitable substrate for larval settlement, as well as enhancement of existing stock to promote increased larval supply. KEY WORDS: oyster fishery, management history, Crassostrea virginica. restoration, environmental disturbances, anthropogenic stressors, overfishing, INTRODUCTION The eastern oyster (Crassostrea virginica) was one of the most valuable fisheries in the United States, but by the early 1900s, many natural oyster reefs were depleted or disappeared [...]

Pacific razor clam shell growth was examined using data provided by the Alaska Department of Fish and Game containing 235,606 length-al-age records based on visible annuli on the shell from 57,534 individual clams measured from 1966 to 2021 at nine locations in Cook Inlet, AK. Shell growth was modeled via the von Bertalanffy Growth Function treating each individual clam as a random effect. Asymptotic mean length at time infinity (LJ varied considerably between sites, from 121.35 to 186.58 mm, as did the growth coefficient k which ranged from 0.28 to 0.54 [y.sup.-1]. When both [L.sub.[infinity]] and k were examined collectively via a growth performance index ([empty set]'), all Cook Inlet sites were similar ([empty set]' range: 3.80-4.02). The growth performance of Pacific razor clams in Cook Inlet was also compared with summary statistics from previously published mean length-at-age estimates for Pacific razor clams across their distribution. Growth performance estimates from Alaska and British Columbia sites were largely similar, whereas sites in Washington, Oregon, and California were generally characterized by faster growth and smaller maximal lengths. Although this study did not attempt to quantitatively identify predictors of variation in growth parameters and performance within and outside of Cook Inlet, AK, this manuscript concludes with speculations on possible correlates to growth and recommendations for future work. KEY WORDS: Pacific razor clams (Siliquapatuld), von Bertalanffy growth function, Alaska, INTRODUCTION The Pacific razor clam, Siliqua patula, is a large bivalve that inhabits fine to medium-grain sandy beaches from southern California to the Aleutian Islands, AK (Weymouth et al. 1925, [...]

A new invasive snapping shrimp from the Alpheus lobidens De Haan, 1849 species complex has become one of the most frequently observed crustaceans in certain saltmarshes along the southwestern Spanish coast. The first place in Europe where this invasion has occurred is reported in this study; however, little is known about this species, even within its undetermined native range. Here, the population structure, density, sex ratio, sexual dimorphism, reproductive period, and relative growth of this nonnative shrimp are reported for an intertidal saltmarsh in SW Spain based on monthly data collection over a year. Ovigerous females were collected during all months of the year. This population trait is not found in any native crustacean in the temperate zone of Europe. The sex ratio showed a similar proportion of male and female individuals, 0.88:1 (F:M), throughout the year. Sexual dimorphism was evident in the growth characteristics of body structures and implications are discussed. These results highlight the successful establishment of this shrimp in the Mediterranean climate area of Spain and have implications on marine fauna conservation and management. These findings also provide a basis for future comparative research in the shrimp native regions and enhance understanding of the species population dynamics. KEY WORDS: Alpheus lobidens, nonindigenous species, Caridea, life-history traits, size, reproduction, San Pedro River, snapping shrimp, INTRODUCTION The caridean family Alpheidae Rafinesque, 1815, is present in various marine habitats, spanning tropical, and temperate regions and can be found from the intertidal zone to deep waters (Anker [...]

Trends in Atlantic surfclam (Spisulu solidissima) population demographic parameters were analyzed using age and length observations obtained from NOAA stock surveys conducted from the 1980s to 2010s in six regions distributed along the Middle Atlantic Bight (MAB) continental shelf. Atlantic surfclam asymptotic length and specific growth rate were estimated for each survey region and decade using the von Bertalanffy growth function. Specific mortality rates were estimated using a linearized negative exponential relationship and the maximum Atlantic surfclam age observed in each survey region for each decade. The estimated Atlantic surfclam mean length in the southern regions of the MAB decreased from 127 to 103 mm, about a 19% decrease, over the four decades. The mean length remained stable at about 130-135 mm in the central survey regions in contrast to the mean length of the Georges Bank Atlantic surfclam population which showed an increase from 101 to 135 mm over the four decades. The asymptotic length estimated for the southernmost survey region declined by 20% and remained relatively constant for the other survey regions over the four decades. Estimated specific growth rates remained unchanged for most of the survey regions, with the overall regional mean decreasing from about 0.25 [y.sup.-1] in the 1980s to 0.20 y~' by the 2010s. Specific mortality rates were not significantly different across the survey regions, although the maximum age estimated for the population in the southern survey region decreased by about 36%. This study provides a quantitative assessment of past and ongoing changes in MAB Atlantic surfclam population demographics that can be used to develop projections of responses to stresses imposed by climate change and commercial fishing. KEY WORDS: Atlantic surfclam Spisulu solidissima, population demographics, growth rale, mortality rate. Middle Atlantic Bight, INTRODUCTION The Middle Atlantic Bight (MAB) region, the portion of the Northwest Atlantic continental shelf from Cape Hatteras to Georges Bank (Fig. 1), is characterized by a productive benthic ecosystem [...]

Benthic habitat and macrobenthos recovery were measured over an 11-y period beginning in January 2002 following the closure of a green-lipped mussel farm in the Marlborough Sounds, New Zealand. Habitats and abundance of eight invertebrate species were compared under two types of farming structures (production backbones and warps) used to grow mussels and secure the farm to the seabed, adjacent areas unaffected by farming served as the control reference. The mean percent of the seabed covered by mussel shells under backbones declined from 38% to 0% after 11 y whereas deposition of shells beneath warps was low ( 0.05) between backbones, warps, and reference sites. The mean abundance of invertebrates was significantly and positively (three species) or negatively (three species) related to the percent shell cover on the seabed. Recovery of four epibenthic species was rapid with mean densities beneath backbones similar to reference sites after 1- to 2-y following farm closure. Densities of the fifth species resembled that at reference sites after 10 y whereas the remaining three species did not differ from controls. Multivariate analyses showed that epibenthic invertebrate communities beneath warps were similar to reference sites throughout the entire 11-y study period. Communities beneath the two backbones differed initially from reference sites but were similar to reference sites 6- and 8-y postfarm closure. After establishing the importance of percent shell cover as an indicator of effects on epibenthic species, data from multiple mussel farms in the Marlborough Sounds were analyzed. These analyses showed that the mean percent of mussel shells beneath backbones (x = 29.5%, range = 0%-100%), exceeded that beneath warps (x = 2.3%), and at reference sites (x = 0.08%). Analyses also showed that the mean maximum distance of mussel shell deposition was 13.5 m distance (range = 1.5-26.5 m) away from farms and was positively (P < 0.01) related to the depth of water where farms were located. Based on multiple mussel farms, mean mussel shell cover declined to below a possible impact threshold of 7% by 7.5 m distance for farms in 20 m depth). Taken together, the effects of mussel farm on epibenthic species abundance as well as overall community structure showed relatively localized impacts, that recovery occurred within 1-10 y following farm removal and that percent shell cover appears to be a useful indicator of effects of mussel farming on the epibenthos. KEY WORDS: aquaculture, green-lipped mussels, ecological recovery, epibenthic impacts, shell deposition, Marlborough Sounds, INTRODUCTION Aquaculture continues to expand to meet global protein demands. Increased efforts and pressure for sustainable farming methods are required to support the social license to operate (e.g., Hynes et [...]

The structure and composition of mantle tissue from red abalone Haliotis rufescens were studied in relation to pearl farming. Histological (hematoxylin-eosin) and histochemical (PAS AJcian Blue. Sudan Black. Dahl's) tools were used to determine variations in the glycogen index, lipid index, and calcium coverage index of mantle tissue as a function of seasonality (cold and warm period) and body region (dorsal, central, ventral). Anatomically, only two well-developed and functional mantle folds (inner and outer) were observed across the marginal zone, together with a poorly developed, and presumably, rudimentary fold with the same cellular morphology as the inner fold. The inner mantle epithelium stored significantly higher concentrations of glycogen and mucins, triglycerides, and calcium than the outer epithelium. This pattern occurred significantly more during the cold season than during the warm season. Mucins from mantle tissue not only regulate crystal nucleation and orientation during biomineralization, but also give the inner nacreous layer its luster and color. High concentrations of lipids in mantle tissue could help compensate for the energy loss caused by the wound-healing processes associated with mantle tissue removal and seeding, which are stressful and energetically costly. The absorption of calcium ions from the environment to integrate a mierolaminate of calcareous compounds gives the shell its structural properties of hardness and strength. An approach with molecularultrastructural tools is recommended to broaden the understanding of mantle tissue regionalization and its relationship to pearl sac formation, which may help increase pearl yield and quality in H. rufescens. KEY WORDS: abalone, calcium, lipids, mantle tissue, nacre, pearls, INTRODUCTION In most molluscan classes, mantle tissue is responsible for forming a hard calcareous shell from elements and ions taken from the environment. This process, known as biomineralization, provides the [...]

The supply of macroalgal feed materials for abalone aquaculture is threatened by increasing costs, limited availability. and the allocation of seaweed resources for other purposes. The use of biofouling Sargassum horneri (SH) as additional macroalgal biomass for abalone has been studied, albeit full inclusion is discouraged due to low utilization. This study applied heat treatment and fermentation to increase the nutritive value of SH meals for the aquaculture feed industry. Untreated (UN) as control, heat treated (HT, 121[degrees]C for 20 min), and fermented (FE, 10' CFU/mL each of Bacillus sp. SJ-10 and Bacillus sp. KRF-7) SH meal was fed to the abalone (11.60 [+ or -] 0.02 g body weight and 42.98 [+ or -] 0.53 mm shell length) for 8-wk growth trial. The results showed that there is no apparent difference in the growth performance (body weight and shell length morphometries) and survival of abalone given experimental diets (P > 0.05). The crude protein, lipid, and ash composition of edible abalone flesh were similarly unaffected (P > 0.05). The gut microbiota profile of abalone was analyzed through next-generation sequencing. The [alpha]-diversity indicators (microbial richness and abundance) were statistically similar (P > 0.05). and the [beta]-diversity of operational laxonomic units revealed short distances within samples and clustering among diet groups. The core phyla (Fusobacteria, Proteobaeteria. Tenericutes) and genera (Psychrilyohacter, Vibrio, Mycoplasma) known to inhabit the gut of abalone predominantly were likewise identilied irrespective of diets; however, there is a difference in their relative abundance. Genus Psychrilyohacter was relatively abundant in UN and FE compared with HT, whereas Vibrio and Mycoplasma had higher abundance in FE and HT-fed abalone, respectively. Taste sensory attributes were discriminated in the abalone meat using an electronic tongue. Principal component analysis of sensor scores revealed several overlapping points, resulting in a negative discrimination index (-184). which means no apparent difference in the general taste profile was detected. Furthermore, the taste screening matrix through radar mapping revealed slight intensity differences in the umami. saltiness, and sourness flavor. Overall, the methods used for heat treatment and fermentation procedures herein were ineffective in improving the nutritive value of seaweed meal for abalone. KEY WORDS: abalone, gulfweed. heat treatment, fermentation. Haliotis discus harmed, Sargassum horneri, INTRODUCTION The abalone (Haliotis spp.) is an ecologically and economically important marine gastropod mollusc worldwide. They are found in tropical and temperate regions, particularly in the low intertidaj zone of [...]

The northern quahog, Mercenaria mercenaria (= hard clam) is an important aquaculture species on the U.S. east coast and shares a partially sympatric distribution with a sister species Mercenaria campechiensis which is endemic to the mid-Atlantic coast from the Chesapeake Bay to Florida and the Gulf of Mexico. These two species are morphologically similar, and their identification is laborious and challenging. To support aquaculture breeding and restoration activities, it is essential to develop an accurate and easy method to identify the two Mercenaria species. In the present study, high-melting resolution analysis was applied to identify these two Mercenaria species and their hybrids using three genes of cytochrome oxidase subunit 1 (COJ), mitochondrial large ribosomal subunit (I6S r RNA), and internal transcribed spacer 1 (ITSI). The temperature melting points (TJ of COl, 16S rRNA, and ITSI were significantly different between the two Mercenaria species and could be used to distinguish M. mercenaria and M. campechiensis. By use of the melting T of COl, 16S r RNA, and ITSI, a discriminant function equation was established to effectively eliminate the impacts of intraspecific sequence variations on species identification. Compared with their true species classification, the accuracy of the predicted classification of each sample was 100% based on the discriminant function equation. Furthermore, a linear discriminant analysis model was used for cross-validation and the mean classification success was 100% with no observed erroneous classification. Moreover, the interspecific hybrids of M. mercenaria and M. campechiensis were verified by the melting curve of nuclear DNA marker ITSI, and their maternity was further clarified by mitochondrial DNA markers COl and 16S rRNA. The methodology developed in this study would be useful as a rapid and accurate tool to support Mercenaria aquaculture, breeding, and restoration. KEY WORDS: high-resolution melt analysis, Mercenaria mercenaria, Mercenaria campechiensis, species identification, hybrid, discriminant analysis, INTRODUCTION The northern quahog, Mercenaria mercenaria (also named hard clam) is an intertidal benthic infaunal species along the western Atlantic coast from the Gulf of St. Lawrence to Florida (Harte [...]

Chaperonin-containing T-complex polypeptide 1 (CCT) is a molecular chaperone in the cytoplasm of eukaryotic cells involved in the correct folding and assembly of proteins, which plays an important role in cold-stress response. This study cloned two transcripts of Pinctada maxima CCT-beta composed of 1,829 bp (CCT-betal) and 2,289 bp (CCT-beta2), respectively, using rapid amplification of cDNA ends. Both transcripts possess 105 bp of 5' noncoding region and the same coding region, bul contain different 3' noncoding regions of 591 bp (CCT-betal) and 131 bp (CCT-beta2), respectively. The open reading framework (ORF) consisted of 1,593 bp that encodes 530 amino acids. The CCT-beta protein has three conserved functional domains (equatorial, apical, and intermediate domains), three CCT-family signature sequences, nine conserved ATP-binding sites, one DEAD box motif, and three protein-binding sites. The CCT-beta is highly conserved, with the cDNA homologies between P. maxima and Crassostrea gigas, Danio rerio, and Homo sapiens being 90.4%. 76.8%, and 75.8%, respectively. Real-time quantitative PCR showed that CCT-beta was differentially expressed in different organs of P. maxima, with mRNA contents declining from the gill, adductor muscle, foot, labial palps, mantle, and heart to hepatopancreas. Under cold stress, CCT-beta mRNA expression in various organs increased, but the patterns of increase varied among organs. The transcriptional level of CCT-beta peaked at 6h in the heart and hepatopancreas, and decreased significantly at 12h. In the adductor muscle, gill, and mantle, CCT-beta mRNA increased significantly at 12h and declined markedly at 24h in cold stress-exposed animals. These results indicate that CCT-beta is a cold-stress response gene, but the response pattern varies among organs. Organs with low CCT-beta basal expression may be more sensitive to cold stress than the organs with relatively high basal expression content. KEY WORDS: Pinctada maxima, CCT-beta, cDNA, cold stress, INTRODUCTION Chaperonin-containing T-complex polypeptide 1 (CCT) is a kind of type II chaperonin that is localized in the cytoplasm of eukaryotes (Frydman et al. 1992, Gao et al. 1992, Lewis [...]

Tetramine [telramelhylammonium ion. [(C[H.sub.3]).sub.4]N*] is a toxic substance found in marine predatory gastropods causing food poisoning when consumed. Despite a considerably high consumption of carnivorous marine gastropods in Korea, studies in tetramine are limited in Korea. This study analyzed tetramine content in eight carnivorous and four herbivorous marine gastropod species obtained from the east coast of Korea using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Method validation showed good linearity (r over 0.999) with a wide linear range (0.1-50 nig/kg), low method detection limit (0.008 0.011 mg/kg), and low method quantitation limit (0.025-0.033 mg/kg) in low-fat/high-fat matrices. The intraday (n = 5) and interday (3 days, n = 15) accuracy and precision results met the CODEX guidelines. The salivary glands of Neptunea showed higher tetramine levels than the other species, and the average tetramine content of the salivary glands was higher in the order of Neptunea eumingii (7,610 mg/kg), Neptunea arthritica (4,950 mg/kg), and Neptunea eulimata (2,710 mg/kg). Tetramine content was higher in the salivary gland (up to 16,700 mg/kg) than in other tissues. Tetramine was detected only in the predatory species in the genus Neptunea, not in herbivorous gastropod species. To prevent tetramine food poisoning, the salivary glands of the predatory gastropods should be removed when they arc cooked and served. KEY WORDS: LC MS/MS, tetramine, Neptunea, whelk, food poisoning, INTRODUCTION Marine gastropods are popular edible shellfish consumed in Korea as canned foods typically made from the whelk, Buccinum undatum. Additionally, B. undatum is imported into Korea after being caught [...]