Shrimp Crangon Research Articles

Gut content metabarcoding of six crustaceans provides detailed diet description and insights into their roles as predators and scavengers

While many studies have analyzed the diet of marine consumers using traditional morphology-based methods, the integral diet of many species of functionally important groups such as benthic invertebrates remains poorly resolved. This hinders our ability to precisely establish trophic links among species, which is necessary to understand food webs and ecosystem dynamics. Here, we applied DNA metabarcoding to obtain a high resolution picture of the animal fraction of the diet of six species of crustaceans in the Bay of Biscay; the edible crab Cancer pagurus, the velvet crab Necora puber, the circular crab Atelecyclus undecimdentatus, the spider crab Maja brachydactyla, the shrimp Crangon crangon, and the hermit crab Pagurus bernhardus. We used two pairs of primers targeting the 18S rDNA (generalist) and 12S rDNA (fish-specific) regions to identify prey that makes up the animal fraction of the diet. Based on occurrence data, 54 prey taxa belonging to 5 different phylum mostly represented by teleost fishes and malacostracans were identified. Through a high-level of prey detection, results indicate a scavenging strategy across all consumers mostly based on the consumption of preys likely originating from fishing discards. This study also reveals patterns of niche overlaps among consumers differentiating C. crangon from others and suggesting high overlap in animal resource use between N. puber and M. brachydactyla as well as C. pagurus. High resolution diet description revealed the complexity of trophic interactions on a local scale.

Dynamic visual noise has limited influence on the habitat selection and behavioural activity of crustaceans and cephalopods

AbstractEnvironments contain various forms of noise that can interfere with the ability of animal sensory systems to perceive information. One ubiquitous type of visual noise in shallow aquatic habitats is caustic flicker (or caustics), consisting of dynamically moving light patterns caused by the refraction of light when passing through the water's rippling surface. While some teleost fish avoid environments with caustic noise (where their prey can be more difficult to detect), it remains untested whether caustics affect the habitat selection of invertebrates. In the present study, we ask whether three invertebrate species, the shore crab Carcinus maenas, the brown shrimp Crangon crangon, and the common cuttlefish Sepia officinalis, prefer or avoid associating with environments with caustic noise, and whether caustics affect their behavioural activity and habitat exploration. To do this, we exposed the three species in binary choice experiments to different simulated caustic noise levels varying in their temporal (speed) and spatial (definition) components. Neither of the three tested invertebrate species spent more or less time in environments with higher caustic noise levels. While we also found no evidence that caustics affected the behavioural activity and exploration of Ca. maenas and S. officinalis, the brown shrimp Cr. crangon reduced its activity with increasing spatial caustic noise. However, all obtained effect sizes in this study were small, suggesting that caustic noise only minimally affects invertebrate behaviour. Overall, our results show that, unlike in teleost fish, caustics have limited influence on the habitat selection, exploration, and activity of crustaceans and cephalopods.

Toxic metals and essential microelements level in brown shrimp Crangon crangon (Linnaeus, 1758) from Bulgarian Black Sea coast as a biomonitor Southern and Northern

Toxic metals and essential microelements level in brown shrimp Crangon crangon (Linnaeus, 1758) from Bulgarian Black Sea coast as a biomonitor Southern and Northern

Diacylglycerol acyltransferase (DGAT) in Crangon crangon and Pandalus montagui (Decapoda, Caridea) - Implications for lipid storage capacities and life history traits.

Lipids play essential roles in cell-structuring, cell-signaling, and as efficient metabolic energy stores. Lipid storage capacities determine life history traits of organisms and, thus, their ecological function. Among storage lipids, triacylglycerols (TAGs) are widespread in marine invertebrates. However, abilities to accumulate TAGs can vary even between closely related species, such as the caridean shrimps Crangon crangon and Pandalus montagui. The first species shows low TAG levels throughout the year in the main storage organ, the midgut gland, while the latter accumulates high TAG-levels, peaking in summer. TAGs synthesis is facilitated by the terminal step of the Kennedy-pathway, where the enzyme diacylglycerol-acyltransferase (DGAT) catalyzes the esterification of diacylglycerols with activated fatty acids. We investigated DGAT activity in the midgut gland using a fluorescent enzyme assay. Sequence information was extracted from whole transcriptome shotgun assembly data, that was publicly available on NCBI, and catalytic properties were deduced from molecular structure analysis. C. crangon showed significantly lower TAG synthesis rates than P. montagui, which explains the native TAG levels. Transcriptome data yielded several isoforms of DGAT enzymes in both species. C. crangon DGAT showed point mutations, which are capable of obstructing the catalytic capacity. The consequences are limited starvation resistance and, thus, presumably restricting C. crangon to a habitat with year-round sufficient food. In contrast, higher TAG synthesis rates presumably enable P. montagui to extend into northern subarctic habitats with limited food availability in winter. Moreover, the limited TAG synthesis and accumulation in the midgut gland may force C. crangon to direct energy into the ovaries, which results in multiple spawnings.

Sanderlings Feed on a Diverse Spectrum of Prey Worldwide but Primarily Rely on Brown Shrimp in the Wadden Sea

Knowing what birds eat is fundamental to understand the ecology and distribution of individuals and populations. Often, diet is assessed based on field observations and excrement analyses, which has previously been the case for Sanderling Calidris alba. This may have biased their known diets towards large prey with indigestible body parts that can still be recognized in faeces or regurgitations. A literature review of Sanderling diet worldwide showed that Sanderlings exploit a large diversity of prey. We carried out DNA metabarcoding on Sanderling faeces to get a complete view of their diet in the Wadden Sea during staging and moult from late July to early October. Given the diversity of available prey in the Wadden Sea, it was remarkable that 94% of the samples contained Brown Shrimp Crangon crangon which, next to the Shore Crab Carcinus maenas, were also the most abundant species in the samples. This study shows that whereas Sanderling can feed on a large variety of invertebrates, in the Wadden Sea during southward staging they primarily rely on Brown Shrimp

Biological Characteristics and Nutrition of the Shrimp Crangon crangon (Decapoda, Crangonidae) near Kindo Peninsula, White Sea, July–August 2006–2007

Biological Characteristics and Nutrition of the Shrimp Crangon crangon (Decapoda, Crangonidae) near Kindo Peninsula, White Sea, July–August 2006–2007

Molting enhances internal concentrations of fipronil and thereby decreases survival of two estuarine resident marine crustaceans.

In aquatic arthropods, molting is a pivotal physiological process for normal development, but it may also expose them to higher risks from xenobiotics, because the organism may take up additional water during that time. This study aimed to assess the effects of molting on bioconcentration and survival after 96-h exposure to insecticide fipronil with or without oxygenase (CYP450s) inhibitor piperonyl butoxide (PBO) of two estuarine resident marine crustacean species: the sand shrimp Crangon uritai and the kuruma prawn Penaeus japonicus, with 96-h LC50 value of fipronil=2.0µg/L and 0.2µg/L, respectively. Two graded concentrations included group high (H) (equivalent to the 96-h LC50 values) and low (L) (one-tenth of the H group concentration). Molting and survival were individually checked, and internal concentrations of fipronil and its metabolites (fipronil desulfinyl, fipronil sulfide, fipronil sulfone) were measured. The results showed that, only fipronil and fipronil sulfone were detected from organism, and that internal concentrations of these insecticides in molted specimens were higher than those of unmolted ones but comparable with those of dead ones. Accordingly, mortality was more frequent in molted specimens than those that were unmolted. Furthermore, involvement of oxygenase and higher lethal body burden threshold may confer higher tolerance to fipronil in sand shrimp than in the kuruma prawn. This study is the first to demonstrate that the body-residue-based approach is useful for deciphering the causal factors underlying fipronil toxicity, but highlights the need to consider physiological factors in arthropods, which influence and lie beyond body burden, molting and drug metabolism.

Unexpected high discard mortalities of juvenile brown shrimp (Crangon crangon) in the North Sea shrimp fishery

The brown shrimp Crangon crangon is the target species of one of the largest crustacean fisheries in the North Sea, producing considerable amounts of bycatch every season. Mortality rates of bycaught juveniles have traditionally been considered negligible, but this assumption was based on studies with short haul durations and short observation times. We investigated shrimp mortality due to trawling and handling under conditions typical of the commercial shrimp fishery in the German Bight. A total of 1440 juvenile shrimps from 48 hauls with commercial beam trawls was analyzed in discard survival experiments, yielding insights into the effects of haul duration and two prevalent sieving methods (riddle and drum) on mortality rates. Shrimps were observed daily for three weeks to test for delayed mortality and moult performance as an indicator of fitness. On average, ca. 70% of the juvenile shrimps moulted successfully during the observation period, most of them (44.5%) in the first week. On average 6% of the shrimp were already dead in the pit. Mortalities of those transferred alive into the aquarium without passing the sieve reached mortalities over three weeks of up to 22% (June) in the 120 min hauls leading to a total mortality of 28%. Passage though a sieve resulted in a 67% (riddle sieve) or 100% (drum sieve) increase of mortality compared to the level that was observed from samples from the pit before sieving. In May 2016, a special situation was encountered with very high immediate (7.0–35.0%) and increased longer-term (19.4–31.9%) mortalities of juvenile shrimps regardless of treatment, indicating an unknown source of additional mortality. We hypothesize that these higher mortalities may be explained by undersized shrimp experiencing a repeated passage of the catch and sorting process of different vessels. In fact, our study emphasizes that bycatch mortalities of undersized shrimps estimated in earlier studies have been severely underestimated.

Fishing in troubled waters: Limited stress response to natural and synthetic microparticles in brown shrimp (Crangon crangon)

Marine invertebrates inhabiting estuaries and coastal areas are exposed to natural suspended particulate matter (SPM) like clay or diatom shells but also to anthropogenic particles like microplastics. SPM concentrations may reach 1 g per liter and more, comprising hundreds of millions of items in the size range of less than 100 μm. Suspension feeders and deposit feeders involuntarily ingest these particles along with their food. We investigated whether natural and anthropogenic microparticles at concentrations of 20 mg L−1, which correspond to natural environmental SPM concentrations in coastal marine waters, are ingested by the brown shrimp Crangon crangon and whether these particles induce an oxidative stress response in digestive gland tissue. Shrimp were exposed to clay, silica, TiO2, polyvinyl chloride (PVC), or polylactide microplastics (PLA) for 6, 12, 24, and 48 h, respectively. The activities of the anti-oxidative enzymes superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione reductase (GR) were measured. All five particle types were ingested by the shrimp along with food. The presence of the particles in the shrimp stomach was verified by scanning electron microscopy. The activities of the anti-oxidative enzymes did not vary between animals exposed to different types of microparticles and control animals that did not receive particles. The temporal activity differed between the three enzymes. The lack of a specific biochemical response may reflect an adaptation of C. crangon to life in an environment where frequent ingestion of non-digestible microparticles is unavoidable and continuous maintenance of inducible biochemical defense would be energetically costly. Habitat characteristics as well as natural feeding habits may be important factors to consider in the interpretation of hazard and species-specific risk assessment.

Advancing presence and changes in body size of brown shrimp Crangon crangon on intertidal flats in the western Dutch Wadden Sea, 1984–2018

Upon settlement after a pelagic larval phase, brown shrimp Crangon crangon depend on intertidal flats. During low as well as high tide the young brown shrimp play roles as predators of meiofauna and as prey for fish and birds. Unlike the biology of the commercially important adults, knowledge on these juveniles remains sketchy. Here we provide an analysis of 35 years (1984–2018) of brown shrimp monitoring in May–June on intertidal flats in the westernmost Dutch Wadden Sea. Intertidal shrimp densities were sampled bi-weekly at three stations during low tide, using sampling corers. We show that over this 35-year period the appearance of shrimp on mudflats advanced by 12 days (− 0.34 days yr−1). Simultaneously, densities on 7 May increased by more than 2.4 times, from 28 shrimp m−2 in 1984 to 69 shrimp m−2 in 2018. Across years, mean shrimp length decreased from 12.6 to 10.7 mm, but length in early May did not change. The advancement in settlement and the increasing shrimp densities correlated with increases in the seawater temperatures in April more than during earlier times of the year. We propose four interpretations of these changes: (1) shrimp settle on the mudflat when they reach a certain ‘threshold’ length, (2) settlement of shrimp is controlled by a critical period of ‘threshold’ temperature sensitivity, (3) timing of shrimp settlement is a response to food availability on mudflats or (4) a direct response to inferred predation pressure. The different interpretations will lead to different scenarios of change in a warming world.

Large‐Scale Flow Management Action Drives Estuarine Ecological Response

AbstractResource managers rely on large‐scale flow and habitat enhancement actions to support sensitive species in the San Francisco Bay–Delta. The effects of these actions on target species and ecosystems are largely unknown. In 2018, we implemented an ecosystem‐scale experiment to reduce salinity and improve access to high‐quality habitat in Suisun Marsh, California, for Endangered Species Act‐listed Delta Smelt Hypomesus transpacificus. The action included a release of approximately 46 million m3 of additional flow in conjunction with the operation of a novel water management facility, the Suisun Marsh Salinity Control Gates. This experimental action resulted in more low‐salinity habitat in Suisun Marsh than would have been present as compared to similar historical low‐flow summer conditions. We evaluated the effect of decreasing salinity on the species assemblage in Suisun Marsh using a combination of ordination analyses and circular statistics. We focused this analysis on long‐term monitoring data collected within Suisun Marsh during July and August and found that the aquatic community changed significantly in small sloughs but not large‐slough habitat in response to the Suisun Marsh action. The assemblage shift from July to August 2018 differed from historical trends in both slough sizes, albeit not significantly in large‐slough habitat. Specifically, we observed (1) a shift in California bay shrimp Crangon franciscorum and Striped Bass Morone saxatilis abundance like that occurring in low‐salinity, wet water year types; and (2) an uncharacteristic seasonal decline in Black Sea jellyfish Maeotias marginata. We posit that the observed community changes were driven by a combination of behavioral responses to lower‐salinity conditions and physical displacement by directional flow resulting from the flow management action.

Do presence of gray shrimp Crangon crangon larvae influence meiobenthic features? Assessment with a focus on traits of nematodes.

In this study, a microcosm experiment was conducted for 30days to assess the impact of the presence of juvenile gray shrimp Crangon crangon on meiofauna. The results suggested that juvenile shrimp had a significant negative impact on the abundance of nematodes and copepods, but no effect on polychaetes. Moreover, nematodes showed a significant decline in individual weight. The collected nematodes were taxonomically identified and assigned to five functional traits: shapes of the tail and amphid, life history, feeding types, and adult length. The nematode traits were affected by the number of shrimp introduced, and descriptors followed normal or inversed bell-shaped curves. When no shrimp were present, the nematofauna had a higher species richness compared with treatments of 4, 8, and 12 shrimp. Bell-shaped curve patterns were common in relation to the two phases of feeding for C. crangon. During the first phase, C. crangon consumed the nematode species Oncholaimus campylocercoides; thereafter, shrimp fed mostly on the nematode Anticoma eberthi and copepods.

Simple isolation for two forms of malic enzyme from crustacean abdomen muscle

Abstract Two forms of NADP-dependent malic enzyme (ME, EC 1.1.1.40) were purified from the abdomen muscle of the crayfish Orconectes limosus (Rafinesque, 1817) and the shrimp Crangon crangon L., 1758 by affinity chromatography on 2′,5′-ADP-Sepharose 4B, with good qualitative recovery in a single step, using a substrate activation method with a malate–manganese chloride pair. The enzymes were identified by native polyacrylamide gel electrophoresis stained for protein and enzyme activity. The faster migrating mitochondrial enzyme from crayfish is inhibited by sulfhydryl reagent and loses its activity. Ellman’s Reagent, 5,5′-Dithiobis-(2-nitrobenzoic acid) (DTNB), can be used for the differentiation and measurement of cytoplasmic and mitochondrial malic enzyme in decapod crustacean tissue.

Involvement of oxygenase confers higher resistance to neonicotinoid insecticides in estuarine resident sand shrimp Crangon uritai than in kuruma prawn Penaeus japonicus and mysid Americamysis bahia

Globally, neonicotinoid contamination in aquatic environments, including estuarine areas, is a prevailing environmental concern. The estuarine resident marine crustacean sand shrimp Crangon uritai was previously found to have a higher tolerance to neonicotinoids than the marine crustaceans kuruma prawn Penaeus japonicus and mysid Americamysis bahia. Based on these findings, we aimed to explore the mechanisms underlying their differences in insecticide sensitivity. We hypothesized that differences in the structures of their nicotinic acetylcholine receptors (nAChRs) and/or the involvement of a metabolizing enzyme may confer sand shrimp resistance to neonicotinoids. No obvious differences were found in the amino acid residue (position 81) of the loop D region of the nAChR β-subunit among the three crustaceans. A synergistic toxicity bioassay was used to explore candidate metabolizing enzymes, esterase, glutathione S-transferase, and oxygenase. The three species were exposed to two neonicotinoids (acetamiprid and clothianidin) at concentrations equivalent to 1/15–1/10 of 96-h LC50 values and synergists (inhibitors of metabolizing enzyme) or combinations of both. Treatments with the oxygenase inhibitor and the neonicotinoids resulted in increased mortality in sand shrimps but not in kuruma prawns or mysids. Consequently, it was determined that oxygenase may explain the higher resistance of the sand shrimp to neonicotinoid insecticides.

Shell disease does not affect biochemical profiles of the North Sea brown shrimp Crangon crangon.

The brown shrimp Crangon crangon is a key component of the North Atlantic coastal food web and an important target species for the fishery economy. As the brown shrimp contains large amounts of protein and essential fatty acids, its consumption makes it a beneficial choice for humans. Commercially harvested crustaceans like C. crangon are frequently affected by bacterial shell disease, with necrotizing erosions and ulcerations of the cuticle. To determine whether shell disease influences the nutritional value of C. crangon, total protein and lipid contents, as well as fatty acid compositions of muscle tissue and hepatopancreas, together with the hepatosomatic index, were examined in healthy and affected individuals. The biochemical composition of the tissues did not differ significantly between the 2 groups. Also, the hepatosomatic index, as an indicator of energy reserves in shrimps, was similar between healthy and affected animals. Our results indicate that the nutritional value of C. crangon is not affected by shell disease, as long as it remains superficial as in the present study.

Annual variation in the prey utilization of juvenile Japanese flounder in southwestern Hiuchi-Nada, Seto Inland Sea, Japan

Past studies indicated that newly settled juvenile Japanese flounder Paralichthys olivaceus depend on mysids as their main prey source, but little is known about the prey of juveniles in nursery grounds with a low density of mysids. This study aimed to reveal the annual variation in the main prey items of juvenile Japanese flounder in relation to their growth in southwestern Hiuchi-Nada, the Seto Inland Sea, Japan. Juvenile flounder consumed chiefly larval anchovy in 1995 and 1999, while small crangonid shrimp Crangon uritai were the main prey items in 1998, 2003, and 2004. The growth rates of juvenile flounder ranged from 0.82–1.33 mm d−1 during the five years of this study. Mysids were almost absent and small crangonid shrimp were abundant in the study area. Our results indicate that juvenile Japanese flounder prefer larval anchovy, but small crangonid shrimp function as the alternative prey when larval anchovy and mysids are not available in the study area.

Effects of the antidepressant fluoxetine on pigment dispersion in chromatophores of the common sand shrimp, Crangon crangon: repeated experiments paint an inconclusive picture

The effects of antidepressants in the environment are starting to generate considerable interest due to the fact that neurotransmitters influence a range of biological processes. Crypsis is an important behavioural and physiological response in many crustaceans modulated by monoamine and pigment dispersing/concentrating hormones. This study aimed to develop a test methodology and investigate the effects of the selective serotonin reuptake inhibitor (SSRI), fluoxetine, on a chromatophore index and overall carapace ‘darkness’ in the common sand shrimp Crangon crangon. Adult shrimp were exposed for either 1 h, 1 day or 1 week across a range of nominal fluoxetine concentrations (10 ng/L, 100 ng/L and 1000 ng/L) and the chromatophore index or carapace percentage ‘darkness’ was recorded following 30 min on white and black substrates. These experiments were repeated three times using different specimens. Animals became significantly darker (~20%) on darker background and lighter on light backgrounds as one might expect. However, time periods over which the animals were recorded had a significant impact on the colouration suggesting habituation to laboratory conditions. Fluoxetine exposure came up as a significant factor in two of the three trials for the chromatophore index but the results was inconsistent between trials. There was a high degree of correlation between the chromatophore index and the percentage darkness analyses however, there was no significant effects for fluoxetine exposure with the percentage darkness data. We conclude that the effects on antidepressants on colour change remain inconclusive from these experiments and we discuss potential areas to improve the repeatability of the experiments.

Molecular aspects of lipid metabolism in the midgut gland of the brown shrimp Crangon crangon.

The brown shrimp, Crangon crangon, is well adapted to the variable environmental conditions in the southern North Sea. It is very abundant, has high reproduction rates, and holds a key position in coastal ecosystems. This species has very low lipid deposits in the midgut gland, suggesting that the main function of the midgut gland is metabolic turnover rather than energy storage. Based on seasonal gene expression studies and established transcriptome data, we investigated key components of lipid metabolic pathways. Gene expression of triacylglycerol lipase, phospholipase, and fatty acid desaturase were analyzed and compared with that of other digestive enzymes involved in lipid, carbohydrate, and protein catabolism. Our results suggest that gene expression of digestive enzymes involved in lipid metabolism is modulated by the lipid content in the midgut gland and is related to food availability. Brown shrimp seem to be capable of using cellular phospholipids during periods of food paucity but high energetic (lipid) requirements. Two of three isoforms of fatty acid binding proteins (FABPs) from the midgut gland involved in fatty acid transport showed specific mutations of the binding site. We hypothesize that the mutations in FABPs and deficiencies in anabolic pathways limit lipid storage capacities in the midgut gland of C. crangon. In turn, food utilization, including lipid catabolism, has to be efficient to fulfill the energetic requirements of brown shrimp.

Polymerase chain reaction as a promising tool for DNA-based diet studies of crustaceans

Studying the diet of crustaceans based on the direct visual inspection of the gut contents can be difficult because they can ingest only a portion of the prey and further crush it into very small pieces, making a very few food items identifiable. Here, the usefulness of molecular methods to identify the species present in the gut contents of two crustaceans, the shore crab Carcinus maenas and the brown shrimp Crangon crangon, was tested. Stomach contents were removed, and their total genomic DNA extracted followed by amplification (PCR) with four specific prey mtDNA primers. Since both crustaceans are opportunistic predators, preying upon around 40 different species, the study was restricted to common potential preys in the sampled area, the Minho Estuary (Portugal): the common goby Pomatoschistus microps, the ragworm Hediste diversicolor, the flounder Platichthys flesus and the peppery furrow shell Scrobicularia plana. After testing the most appropriate methodology for DNA extraction and PCR amplification to detect the presence of each potential prey with positive control samples, the same methodology was applied to the stomach content samples. The molecular methods allowed for detection of the presence of P. microps, P. flesus and H. diversicolor in the stomachs of both crustaceans. Therefore, once potential prey and their availability in the system are known, PCR technique can be an alternative tool to overcome some of the limitations of traditional methods in the study of the crustaceans’ diet, even when stomach contents include a great part of ‘detritus’. This study reflects also the need to develop more tools (primers) to improve the assessment of predator–prey interactions in aquatic ecosytems.

First report of an idiopathic partial tail myonecrosis in European brown shrimp Crangon crangon caught in the North Sea.

The European brown shrimp Crangon crangon is an abundant and commercially important species in the North Sea. Currently, there is interest in landing live shrimp to provide fresh animals for a growing market in live brown shrimp. During 4 survival studies between 2014 and 2016, shrimp were collected from commercial trawlers and maintained alive in off-shore facilities. From Day 1 onwards, a minority of shrimp (~2.24%) developed a white discoloration of the abdominal muscles and a depigmentation of the distal part of the abdomen, along with paralysis of the affected tissues and appendages. As the symptoms progressed, a circumferential blackish delineation appeared, creating a distinct boundary between healthy and necrotic tissue. Affected shrimp survived up to 3 wk, although in several animals the distal part of the tail was completely lost. Histological and electron microscopical examination confirmed the myonecrosis. A secondary bacterial invasion of the necrotic muscle was observed in some animals. RT-PCR for infectious myonecrosis virus was negative. The condition appears not to be contagious, based on the feeding of healthy shrimp with necrotic tissue of affected shrimp. Based on these observations, a mechanical cause inflicted during the catching process is proposed.