Growth Of Barnacles Research Articles

Molt-dependent transcriptomic analysis of cement proteins in the barnacle Amphibalanus amphitrite.

BackgroundA complete understanding of barnacle adhesion remains elusive as the process occurs within and beneath the confines of a rigid calcified shell. Barnacle cement is mainly proteinaceous and several individual proteins have been identified in the hardened cement at the barnacle-substrate interface. Little is known about the molt- and tissue-specific expression of cement protein genes but could offer valuable insight into the complex multi-step processes of barnacle growth and adhesion.MethodsThe main body and sub-mantle tissue of the barnacle Amphibalanus amphitrite (basionym Balanus amphitrite) were collected in pre- and post-molt stages. RNA-seq technology was used to analyze the transcriptome for differential gene expression at these two stages and liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) was used to analyze the protein content of barnacle secretions.ResultsWe report on the transcriptomic analysis of barnacle cement gland tissue in pre- and post-molt growth stages and proteomic investigation of barnacle secretions. While no significant difference was found in the expression of cement proteins genes at pre- and post-molting stages, expression levels were highly elevated in the sub-mantle tissue (where the cement glands are located) compared to the main barnacle body. We report the discovery of a novel 114kD cement protein, which is identified in material secreted onto various surfaces by adult barnacles and with the encoding gene highly expressed in the sub-mantle tissue. Further differential gene expression analysis of the sub-mantle tissue samples reveals a limited number of genes highly expressed in pre-molt samples with a range of functions including cuticular development, biominerialization, and proteolytic activity.ConclusionsThe expression of cement protein genes appears to remain constant through the molt cycle and is largely confined to the sub-mantle tissue. Our results reveal a novel and potentially prominent protein to the mix of cement-related components in A. amphitrite. Despite the lack of a complete genome, sample collection allowed for extended transcriptomic analysis of pre- and post-molt barnacle samples and identified a number of highly-expressed genes. Our results highlight the complexities of this sessile marine organism as it grows via molt cycles and increases the area over which it exhibits robust adhesion to its substrate.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-015-2076-1) contains supplementary material, which is available to authorized users.

Growth rate variation of the stalked barnacle Pollicipes pollicipes (Crustacea: Cirripedia) using calcein as a chemical marker

This study describes the use of calcein as a chemical tagging methodology to estimate growth rate variation of the stalked barnacle Pollicipes pollicipes, an ecologically important intertidal species and economic resource, in SW Portugal. Calcein tagging had a high success rate (94%) in marking both juvenile and adult barnacles for a period of 2.5 months, providing a valuable method for obtaining reliable data in growth studies of P. pollicipes. Growth rate decreased with barnacle size and was highly variable amongst individuals, particularly in smaller barnacles. No effect of shore level on barnacle growth was detected. Growth rates were higher in smaller juvenile barnacles, peaking at a 1.1-mm monthly increment in rostro-carinal length (RC) for individuals with RC=5 mm, and decreased with barnacle size (monthly growth rates of 0.5 mm for adult barnacles with RC~12.5 mm). Growth rates observed in adults with commercial interest (RC ≥ 18 mm) was < 0.25 mm per month. The advantages of tagging P. pollicipes with calcein were the possibility of mass marking individual barnacles of different size cohorts within a short period (less than 1 day of manipulation); and reduced time of fieldwork, which is very important because this species inhabits very exposed rocky shores.

The effect of water temperature and velocity on barnacle growth: Quantifying the impact of multiple environmental stressors

Organisms employ a wide array of physiological and behavioral responses in an effort to endure stressful environmental conditions. For many marine invertebrates, physiological and/or behavioral performance is dependent on physical conditions in the fluid environment. Although factors such as water temperature and velocity can elicit changes in respiration and feeding, the manner in which these processes integrate to shape growth remains unclear. In a growth experiment, juvenile barnacles (Balanus glandula) were raised in dockside, once-through flow chambers at water velocities of 2 versus 19cms−1 and temperatures of 11.5 versus 14°C. Over 37 days, growth rates (i.e., shell basal area) increased with faster water velocities and higher temperatures. Barnacles at high flows had shorter feeding appendages (i.e., cirri), suggesting that growth patterns are unlikely related to plastic responses in cirral length. A separate experiment in the field confirmed patterns of temperature- and flow-dependent growth over 41 days. Outplanted juvenile barnacles exposed to the faster water velocities (32±1 and 34±1cms−1; mean±SE) and warm temperatures (16.81±0.05°C) experienced higher growth compared to individuals at low velocities (1±1cms−1) and temperatures (13.67±0.02°C). Growth data were consistent with estimates from a simple energy budget model based on previously measured feeding and respiration response curves that predicted peak growth at moderate temperatures (15°C) and velocities (20–30cms−1). Low growth is expected at both low and high velocities due to lower encounter rates with suspended food particles and lower capture efficiencies respectively. At high temperatures, growth is likely limited by high metabolic costs, whereas slow growth at low temperatures may be a consequence of low oxygen availability and/or slow cirral beating and low feeding rates. Moreover, these results advocate for approaches that consider the combined effects of multiple stressors and suggest that both increases and decreases in temperature or flow impact barnacle growth, but through different physiological and behavioral mechanisms.

Substratum fidelity and early growth in &lt;I&gt;Chelonibia testudinaria&lt;/I&gt;, a turtle barnacle especially common on debilitated loggerhead (&lt;I&gt;Caretta caretta&lt;/I&gt;) sea turtles

The barnacle, Chelonibia testudinaria (Linnaeus, 1758), is reported to associate with nearly every species of sea turtle and is particularly common on loggerheads, Caretta caretta (Linnaeus, 1758), with symptoms of Debilitated Turtle Syndrome (DTS). Here, we test recruitment rates of C. testudinaria on various natural and artificial substrata, including carapace from healthy and debilitated loggerheads. In addition, the sizes of individual barnacles were followed through time to estimate early growth rates and to provide attachment duration estimates. Floating racks holding replicate panels of four treatments (DTS turtle carapace scutes, healthy turtle carapace scutes, Plexiglas®, and slate tile) were placed at four independent sites in Charleston County, South Carolina. Panels were monitored for 34-54 d. Our findings indicate that C. testudinaria larvae recruit and grow at significantly higher rates along the open shore vs protected areas, but do not recruit differentially to the four substratum types. Individual barnacle growth was highly variable within and between sites and substratum types; the mean growth rate was 4.28 mm d-1 (95% CI: 3.42-5.14 mm d-1). However, due to the high variability in growth, this value cannot serve as a fine-scale indicator for attachment duration. Further experiments of substratum selection and long-term survival are needed to fully clarify the nature of the barnacle/turtle association.

Habitat traits and food availability determine the response of marine invertebrates to ocean acidification

Energy availability and local adaptation are major components in mediating the effects of ocean acidification (OA) on marine species. In a long-term study, we investigated the effects of food availability and elevated pCO2 (ca. 400, 1000 and 3000μatm) on growth of newly settled Amphibalanus (Balanus) improvisus to reproduction, and on their offspring. We also compared two different populations, which were presumed to differ in their sensitivity to pCO2 due to differing habitat conditions: Kiel Fjord, Germany (Western Baltic Sea) with naturally strong pCO2 fluctuations, and the Tjärnö Archipelago, Sweden (Skagerrak) with far lower fluctuations. Over 20weeks, survival, growth, reproduction and shell strength of Kiel barnacles were all unaffected by elevated pCO2 , regardless of food availability. Moulting frequency and shell corrosion increased with increasing pCO2 in adults. Larval development and juvenile growth of the F1 generation were tolerant to increased pCO2 , irrespective of parental treatment. In contrast, elevated pCO2 had a strong negative impact on survival of Tjärnö barnacles. Specimens from this population were able to withstand moderate levels of elevated pCO2 over 5weeks when food was plentiful but showed reduced growth under food limitation. Severe levels of elevated pCO2 negatively impacted growth of Tjärnö barnacles in both food treatments. We demonstrate a conspicuously higher tolerance to elevated pCO2 in Kiel barnacles than in Tjärnö barnacles. This tolerance was carried over from adults to their offspring. Our findings indicate that populations from fluctuating pCO2 environments are more tolerant to elevated pCO2 than populations from more stable pCO2 habitats. We furthermore provide evidence that energy availability can mediate the ability of barnacles to withstand moderate CO2 stress. Considering the high tolerance of Kiel specimens and the possibility to adapt over many generations, near future OA alone does not seem to present a major threat for A. improvisus.

Nitrogen and phosphorus absorption capability in environmental culture by Taiwan gravestone Anadonta woodiana Lea

&lt;p&gt;Nitrogen and phosphorus in a water culture are derived from the metabolism of the farmed organism, feed residue and microbial activity in the water. One way of controlling water quality due to waste in the form of nitrogen and phosphorus from aquaculture is to utilize filter feeder organisms of &lt;em&gt;Anadonta woodiana&lt;/em&gt; Lea. This study aimed to analysis the effectiveness of the absorption of nitrogen and phosphorus in waters by &lt;em&gt;A. woodiana&lt;/em&gt; as filter feeder. A total of 0 (control), five, ten, and 15 gravestone were putted into a tank of 35 L of water derived from Cirata reservoir. Each treatment was given three times repetition. Measurement of total nitrogen and phosphorus in gravestones were performed at baseline and end of treatment. In addition, measurement of total nitrogen and phosphorus in the water tank was measured every ten days. Another measurement is the length and weight of gravestone. Direct observations made on gravestones barnacle survival, pH, dissolved oxygen, temperature, and turbidity every day. Aeration was provided in each aquarium. Based on the results obtained, the survival of gravestone in the density of five gravestones was 93.33%, in ten gravestones density was 90%, while in 15 gravestones was 95%. The percentage reduction in total nitrogen in the water at the end of treatment was 57% for the five gravestones density, and for ten gravestones was 88.2%. The decrease of total phosphorus in water in ten gravestones density was 37.4%, whereas the increase in density of 15 gravestones and total phosphorus water percentage was 26.9%. On the density of ten gravestones, the body weight decreased until to 3.3%, while in the density of 15 gravestones decreased until to 2.5% on day 30. Results of water quality analysis showed that the DO values decreased from baseline to end of treatment (from 5.08 to 4.86 mg/L), the average water temperature from 26.5 to 27.4 °C, pH values 7‒8, and highest turbidity values was obtained in the density of five gravestone. Decrease in the percentage of total nitrogen in the water suggested nitrogen and phosphorus have been absorbted for barnacle growth.&lt;/p&gt; &lt;p&gt;Keywords: total phosphorus, total nitrogen,waste,&lt;em&gt;Anadonta woodiana&lt;/em&gt; Lea,cultivation&lt;/p&gt;

Monitoring of Barnacle Growth on the Underwater Hull of an FRP Boat Using Image Processing

In this research, photos of barnacles were analysed using image processing. The images of barnacles were taken from the CITRA MOSTI boat made from fibre-glass reinforced plastic (FRP) for monitoring purpose. The photos were taken within a period of three (3) months. Results showed that the barnacles’ growth in terms of their size and quantity might be due to the effect of saltwater. Results obtained through SCILAB programming were analysed and comprehensive data were tabulated. From images recorded on February 2013, it was observed that the barnacles had been growing aggressively achieving the highest pixel count of 3000 as compared to images captured in December that only amounted to 2600 pixels. The barnacles were growing at a rate of approximately 10% from the first image analysis. The highest recorded pixels were in the month of the March 2013, attaining about 3500 pixel counts. These changes in growth rate throughout the stipulated period may be due to numerous factors such as the fluctuating of seawater temperature and weather.

Sexual systems and dwarf males in barnacles: Integrating life history and sex allocation theories

Barnacles, which are sedentary marine crustaceans, have diverse sexual systems that include simultaneous hermaphroditism, androdioecy (coexistence of hermaphrodites and males) and dioecy (females and males). In dioecious and androdioecious species, the males are very small and are thus called dwarf males. These sexual systems are defined by two factors: sex allocation of non-dwarf individuals and the presence or absence of dwarf males. We constructed an ESS model treating sex allocation and life history simultaneously to explain sexual systems in barnacles. We analyzed the evolutionarily stable size-dependent resource allocation strategy to male reproductive function, female reproductive function and growth in non-dwarf barnacles, and the ESS proportion of dwarf males, under conditions of varying mortality and food availability. Sex allocation in non-dwarf individuals (hermaphrodites or females) is affected by mate availability and the proportion of dwarf males. When hermaphrodites appear, all hermaphrodites become protandric simultaneous hermaphrodites. Furthermore, high mortality and poor resource availability favor dwarf males because of their early maturation and weakened sperm competition. In conclusion, we showed that combining sex allocation and life history theories is a useful way to understand various sexual systems in barnacles and perhaps in other organisms as well.

Self-Disinfecting Surfaces

Affiliations: 1. Department of Medicine, University of North Carolina Medical School, Chapel Hill, North Carolina; 2. Department of Hospital Epidemiology, University of North Carolina Health Care, Chapel Hill, North Carolina. Received October 30, 2011; accepted October 31, 2011; electronically published December 7, 2011. 2011 by The Society for Healthcare Epidemiology of America. All rights reserved. 0899-823X/2012/3301-0003$15.00. DOI: 10.1086/663648 Contamination of environmental surfaces in hospital rooms is now recognized as playing an important role in the transmission of several key healthcare-associated pathogens, including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), Clostridium difficile, Acinetobacter species, and norovirus. All of these pathogens have been demonstrated to persist in the environment for hours to days (and in some cases for months), to frequently contaminate the environmental surfaces in the rooms of colonized or infected patients, to transiently colonize the hands of healthcare personnel (HCP), to be transmitted to patients by HCP, and to cause outbreaks in which environmental transmission was deemed to play a role. Furthermore, hospitalization in a room in which the previous patient had been colonized or infected with MRSA, VRE, C. difficile, or Acinetobacter species has been shown to be a risk factor for colonization or infection with the same pathogen in the newly admitted patient. Pathogen transfer from an affected patient to a susceptible host occurs most commonly via the hands of HCP, but contaminated surfaces, objects, and air can be directly or indirectly involved in the transmission pathway. These transmission pathways and methods to interrupt transmission have been diagramed. Transmission can be greatly reduced by hand hygiene of HCP before and after each patient contact and by appropriate disinfection of shared medical devices between patients. However, reducing or eliminating surface contamination is crucial to preventing acquisition of healthcare pathogens by patients who are newly admitted to rooms previously occupied by colonized or infected patients and to minimizing the risk of contaminating the hands of HCP. Potential methods of decreasing contamination of environmental surfaces in hospital rooms have included routine and terminal room disinfection with chemical germicides and, more recently, the use of “no-touch” methods of terminal room decontamination with UV light or aerosolized and/or vaporized hydrogen peroxide. Unfortunately, there are major limitations associated with currently available methods of room decontamination. Multiple studies have demonstrated that less than 50% of hospital room surfaces are adequately cleaned and disinfected when chemical germicides are used, although with implementation of enhanced performance feedback, education, and other interventions, the frequency of appropriate cleaning can be increased to 71%–77%. The major limitation of UV light and hydrogen peroxide is that, because this method requires the removal of patients and HCP from the room, it can be used only for terminal disinfection. Other limitations include the high acquisition costs of room decontamination units and increasing the time of room turnover. In the past several years, another method of reducing contamination of room surfaces has emerged: self-disinfecting surfaces (Table 1). Such surfaces have also been called “selfsanitizing,” and because microbial killing requires direct contact with the surface, the term “contact killing” has also been used. One novel method to achieve contact killing is to cover room surfaces with a transition metal, such as copper or silver. Such metals influence microorganisms by affecting their growth, morphology, and biochemical activities. Toxicity is a result of the blocking of functional groups of important molecules (eg, enzymes), displacement or substitution of essential ions from cellular sites, denaturation and inactivation of enzymes, generation of reactive hydroxyl radicals, and disruption of cellular membrane integrity. Copper is an essential trace element in most living organisms and has been used for centuries as a medicinal as well as to prevent growth of barnacles and weeds on the hulls of ships. Copper surfaces have been demonstrated to be cidal to important healthcare-associated pathogens, including MRSA, Acinetobacter species, Pseudomonas aerugonosa, and influenza virus. Experimental inoculation of copper surfaces has demonstrated that dry metallic surfaces were more antimicrobial than were moist surfaces. On dry surfaces, vegetative bacteria were killed within a few minutes. How soiling,

Long-term in situ observation of barnacle growth on soft substrates with different elasticity and wettability

In this paper, settlement, metamorphosis, and long term growth of barnacles on soft substrates with a wide elasticity range (modulus 0.01–0.47 MPa) as well as with the variation in wettability were investigated for the first time in vitro, in the laboratory environment. Tough double-network (DN) hydrogels and polydimethylsiloxane (PDMS) were used as the soft hydrophilic substrates and hydrophobic substrates, respectively, and polystyrene (PS), a hard and hydrophobic substrate, was used as a control. It was observed that (1) the initial settlement and metamorphosis of cyprid larvae dramatically increase with the substrate elastic modulus while not showing an explicit dependence on the substrate wettability; (2) the growth rate of barnacles on both DN gels and PDMSs does not show an explicit dependence on the elasticity of the soft substrates, while it shows a slightly higher value on the hydrophobic PDMSs than on the hydrophilic DN gels; (3) the growth rate on these soft substrates is explicitly lower than that on the rigid PS substrate at the late stage of the growth; (4) the “self-release” phenomenon of barnacles was observed for the PDMS substrate with a modulus higher than 0.01 MPa. Based on these observations, the antifouling effects of the soft substrates on barnacles were discussed.

Coupling between subtidal prey and consumers along a mesoscale upwelling gradient in the Galápagos Islands

Our understanding of how communities are regulated diminishes with increasing spatial scale. Because oceanographic processes supply food, transport propagules, and set abiotic conditions across broad areas, they may explain metacommunity and food web functioning on large scales. Here we test for bottom‐up manifestations of an oceanographic process, upwelling, through production of barnacle (Megabalanus spp.) prey to top‐down control by whelks, fish, and urchins across a mesoscale (125 km) gradient of 28–68% upwelling at 12 subtidal rock wall sites in the Galápagos from 2002 to 2005. Multivariate analysis of in situ flow measurements and the occurrence of the Equatorial Undercurrent (EUC) distinguished weak (WUP), intermediate (IUP), and strong upwelling (SUP) site groups. Barnacle cover and recruitment were significantly higher at SUP than at WUP sites and decreased with depth from 6 to 15 m. High barnacle recruitment was a persistent feature of SUP sites from 2002 to 2004. This recruitment was significantly related to larval concentrations, vertical flow speeds, and to a lesser extent, onshore offshore flow speeds, while growth rates of barnacles were highest at three SUP and one IUP site. Three‐dimensional (3‐D) flow explained 39% of the variation in growth. Therefore, bottom‐up effects of upwelling occurred via prey production as recruitment and growth of barnacles. Vertical flow was the most important component of the upwelling regime predicting these dynamics.Evidence of population level predator–prey coupling was provided by significant linear relationships between densities of the whelk, Hexaplex princeps, and both the cover and recruitment of barnacle prey. In a mesoscale predation intensity experiment 33–100% of barnacles were eaten by Hexaplex and fish, linking bottom‐up and top‐down effects. Significantly more barnacles were consumed at SUP than at WUP sites. The broader spatial context for upwelling and predator–prey coupling documented here was provided by the topography of the sea floor offshore, as the maximum depth and bottom slope within 15 km of the sites predicted 40% of upwelling duration. Eighty percent of the SUP sites were close to steep slopes and deep (&gt;1100 m) water where upwelling from internal waves and the EUC is likely.

Conceptual issues in designing a policy to phase out metal-based antifouling paints on recreational boats in San Diego Bay

In marine areas throughout the world where recreational boats are densely located, concentrations of copper in the water are being found to be in excess of government standards, due to the hull coatings used on these boats. Copper-based hull coatings are intended to be antifouling in that they retard the growth of algae, barnacles and tubeworms; but alternatives exist that can eliminate the harm that copper contamination does to marine organisms. A variety of policy options are available to mandate or provide economic incentives to switch to these less harmful alternatives. This paper puts forth a conceptual framework for thinking about how to design and evaluate alternative policies to transition to nontoxic boat hulls, drawing from the authors' experience designing a policy for use in San Diego Bay. Many of the issues raised are broadly applicable to environmental problems where the solution involves a large-scale replacement of durable consumer goods.

Growth and survival of barnacles in presence of co-dominating solitary ascidians: growth ring analysis

Marine and terrestrial communities are often hierarchically structured by one or more foundation species, which provide habitats for many other taxa. Interactions between coexisting habitat modifiers may have strong effects on patterns and processes in the dependent assemblage. Yet they are rarely studied, especially at a small scale. Small epibenthic patches co-dominated by barnacles Balanus crenatus Brugiere and several species of solitary ascidians in the White Sea soft bottoms support many dependent species. Barnacles occupy bivalve shells, small stones and conspecifics. Ascidian clumps develop on barnacles and their empty shells. Previous observations suggest that at the patch scale ascidians may replace barnacles over several years likely because of the negative interactions between them. Barnacles have distinct annual growth rings on their shells, which we used to trace their growth and survival in the field. No difference between the patches with different dominants would evidence no pronounced negative effect of ascidians. In the patches dominated by ascidians (A) or barnacles (B) collected at the same subtidal site in 2004 and 2005 we compared lengths of recent annual vertical growth increments and dead:live ratios of barnacles of the same age class according to the growth rings. Barnacles grew slower in A than in B, regardless of the biomass of conspecific neighbors. Dead:live ratios were higher in A for age classes 1+…2+ and 4+…9+. Estimated mortality risk between A and B increased with age of barnacles, from around 1:1 to 5.6 times greater in the 9+ age group. Because of the observed difference in growth and survival, the negative effect of adult ascidians on barnacles could not be excluded; alternatively, ascidians may prefer the patches with declining barnacles, or there could be an unknown external process that negatively affects barnacles and favors ascidians.

Barnacle growth rate on artificial substrate in the Salton Sea, California

The Salton Sea is one of the few saline, inland lakes in the world with a population of barnacles, Balanus amphitrite. It is also one of California’s most impaired water bodies due to excessive nutrient loading which leads to phytoplankton blooms and low dissolved oxygen. Currently, B. amphitrite growth is limited due to lack of hard substrate in and around the Sea. We have hypothesized that artificial substrate could support the growth of B. amphitrite and their filter-feeding would lead to improved water quality. Periodic harvesting of the barnacles would result in the permanent removal of nitrogen and phosphorus from the Sea. A 44-day in-situ experiment was carried out in the Salton Sea to assess the rate of barnacle growth and phosphorus and nitrogen sequestration on burlap sheets suspended vertically from a floating line. Burlap panels were collected weekly and the barnacles analyzed for Ca, total-P, inorganic-P, total-N, total-C, CaCO3, and organic matter content. After 44 days of growth, the barnacle mats weighed 7.4 kg m−2 on a dry weight basis, with 80% of the mass as shell material. The nutrient sequestration was 9.4 g P m−2 and 100 g N m−2. Approximately half of the P was inorganic and appears to be coprecipitated with the calcium carbonate shell material. Results indicate that harvesting barnacles grown on artificial substrate in the Salton Sea would not be an effective method for removing N or P from the lake because of the relative proportions of shell material and organic material.

Temporal changes in the strength of density‐dependent mortality and growth in intertidal barnacles

1. In demographically open marine systems, the extent to which density-dependent processes in the benthic adult phase are required for population persistence is unclear. At one extreme, represented by the recruitment limitation hypothesis, larval supply may be insufficient for the total population size to reach a carrying capacity and density-independent mortality predominates. At the opposite extreme, populations are saturated and density-dependent mortality is sufficiently strong to reshape patterns established at settlement. 2. We examined temporal variation in the way density-independent and density-dependent mortality interact in a typical sessile marine benthic invertebrate, the acorn barnacle Semibalanus balanoides (L.), over a 2-year period. 3. Recruitment was manipulated at two high recruitment sites in north Wales, UK to produce recruit densities covering the range naturally found in this species. Following manipulation, fixed quadrats were monitored using digital photography and temporal changes in mortality and growth rate were examined. 4. Over a 2-year period there was a clear, spatially consistent, over-compensatory relationship between the density of recruits and adult abundance indicating strong density-dependent mortality. The strength of density dependence intensified with increasing recruitment. 5. Density-dependent mortality did not operate consistently over the study period. It only operated in the early part of the benthic phase, but the pattern of adult abundance generated was maintained throughout the whole 2-year period. Thus, early life-history processes dictated adult population abundance and dynamics. 6. Examination of the natural recruitment regime in the area of study indicated that both positive and negative effects of recruitment will occur over scales varying from kilometres to metres.

Juvenile growth in barnacles: combined effect of delayed metamorphosis and sub-lethal exposure of cyprids to low-salinity stress

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 344:173-184 (2007) - DOI: https://doi.org/10.3354/meps06931 Juvenile growth in barnacles: combined effect of delayed metamorphosis and sub-lethal exposure of cyprids to low-salinity stress V. Thiyagarajan1, J. A. Pechenik2, L. A. Gosselin3, P. Y. Qian1,* 1Department of Biology/Coastal Marine Laboratory, The Hong Kong University of Science and Technology, Kowloon, Hong Kong SAR 2Department of Biology, Tufts University, Medford, Massachusetts 02155, USA 3Department of Biological Sciences, Thompson Rivers University, Kamloops, British Columbia V2C 5N3, Canada *Corresponding author. Email: boqianpy@ust.hk ABSTRACT: Delayed metamorphosis can affect post-metamorphic performance in a variety of marine invertebrate species, possibly through effects on larval energy reserves. Nevertheless, the consequences of the ‘latent effects' of natural environmental conditions and the proximate causes of the effects have rarely been examined. We documented the combined effect of delayed metamorphosis and sub-lethal exposure of larvae to low-salinity stress on depletion of energy reserves, metamorphic success and juvenile growth rates for the estuarine barnacle Balanus amphitrite, both in the laboratory and in field outplant experiments. Acute (24 h) exposure of 0 d old cyprids to low salinity (10 psu) dramatically reduced juvenile growth rates (measured as basal diameter, dry weight and ash-free dry weight) for the first 5 d after metamorphosis, in both laboratory and field conditions, and the effects were similar to those resulting from delayed metamorphosis. There was an interaction between delayed metamorphosis and salinity effects on juvenile tissue growth rates. To determine how the negative effects of delayed metamorphosis observed in the laboratory might be modulated in the field under different nutrient conditions, we also outplanted juveniles from cyprids that had delayed metamorphosis for either 0 d (control) or 4 d at 2 intertidal sites that experienced different nutrient conditions. Surprisingly, surplus food availability in the juvenile habitat could not entirely compensate for the negative effects imposed by delayed metamorphosis on juvenile growth rates. Additionally, we examined whether or not the detrimental effects of delayed metamorphosis on growth were mediated through effects on juvenile feeding rates and feeding appendage (cirri) morphology. Interestingly, although 2 out of the 3 juvenile feeding cirri lengths were shorter than expected in delayed individuals, mean juvenile filtration rate was significantly higher in delayed individuals than in control individuals. Overall, our results emphasise that acute exposure of competent larvae to low-salinity stress negatively affects juvenile growth rates as severely as delayed metamorphosis, which may ultimately influence juvenile and adult population dynamics in the field. The cause of reduced post-metamorphic performance in young barnacles remains unclear, but does not seem to be caused by reduced capacity for feeding. KEY WORDS: Barnacle · Balanus amphitrite · Juvenile growth · Delayed metamorphosis · Lowsalinity stress · Latent effects Full text in pdf format PreviousNextCite this article as: Thiyagarajan V, Pechenik JA, Gosselin LA, Qian PY (2007) Juvenile growth in barnacles: combined effect of delayed metamorphosis and sub-lethal exposure of cyprids to low-salinity stress. Mar Ecol Prog Ser 344:173-184. https://doi.org/10.3354/meps06931 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 344. Online publication date: August 23, 2007 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2007 Inter-Research.

Comparative growth of the intertidal barnacle Tetraclita stalactifera (Thoracica: Tetraclitidae) in sites influenced by upwelling and tropical conditions at the Cabo Frio region, Brazil

Growth of the intertidal barnacle Tetraclita stalactifera was compared in two sites under upwelling and tropical influence at Cabo Frio region, Brazil. The hypothesis was that growth is higher at sites with an enhanced productivity. Five quadrates of 10 x 10 cm were cleared in an intertidal zone of each site to follow growth from recruitment and onwards. Base diameters were measured for 18 individuals at the tropical site (Ponta da Fortaleza) and 22 at the upwelling site (Ponta da Cabeça) using digitalized photos and ImageTool software. Mean growth rates were 0.07 mm/day at the tropical site and 0.06 mm/day at the site under upwelling influence. No effect of location, upwelling season or settlement time was found on barnacle growth rates. Other factors or synergic interactions such as temperature and food availability could influence T. stalactifera growth.

Differential growth of the barnacle Notobalanus flosculus (Archaeobalanidae) onto artificial and live substrates in the Beagle Channel, Argentina

In the Beagle Channel, southern South America (ca. 55°S 67°W), about 20% of false king crabs (Paralomis granulosa) >80 mm carapace length are fouled with the barnacle Notobalanus flosculus. To evaluate differences in growth rates of barnacles attached to artificial and live substrates, clay tiles were anchored as collectors to the bottom at two different sites in the Beagle Channel in September 1996: in Ushuaia harbour (low currents and high levels of suspended matter) and around the Bridges Islands (strong currents and low level of suspended matter). Another set of collectors was deployed at the same sites in October 1998 to collect barnacles for histological studies. Tiles were removed from each place, approximately, on a monthly basis. Carapaces of P. granulosa with the epizoic N. flosculus were sampled between November 1996 and 1997, and between March 1998 and September 1999, to study sexual maturation of barnacles. Growth of barnacles was compared between the collectors and P. granulosa carapaces following a qualitative approach. A sexual maturity scale was defined, based on the stage of development of the female reproductive apparatus of N. flosculus. Growth rate of barnacles was highest in the harbour, intermediate on P. granulosa, and lowest around the Bridges Islands. Presence of oocytes was registered only in epizoic barnacles, suggesting that at least a proportion of these individuals is able to spawn on the carapaces. The potential advantages of settling on a living substrate, namely increased availability of food particles and decreased predation risks are discussed.

野外におけるタテジマフジツボの蔓脚運動に及ぼす水温，塩分，珪藻密度の影響

Investigations of the factors that influence the cirral beating of barnacles are important because the survival and growth of barnacles after adhesion and metamorphosis depend on cirral beating. Only while beating their cirri are barnacles able to catch and ingest food, respire, and engage in reproduction and excretion. Although there have been some reports concerning barnacle cirral beating in the laboratory, there have been none with respect to this behavior in the field. The present research concerns the influences of water temperature, salinity, and diatom density on cirral beating in a species of sessile barnacle (Balanus amphitrite) in northern Osaka Bay, Japan. Cirral beating was observed throughout one year except when water temperature fell below 7°C, or salinity below 16.20‰. The frequency of cirral beating rose with rising water temperature but declined as the water cooled. Neither the highest water temperature (32.3°C) nor the highest salinity (32.16‰) observed during this study stopped cirral beating. Water temperature strongly affected the frequency of cirral beating in B. amphitrite, and to a lesser degree so did salinity, but diatom density did not.

Growth and survival of juvenile barnacle Balanus amphitrite: interactive effects of cyprid energy reserve and habitat

Using factorial laboratory and field-transplant experiments, we have examined the effects of cyprid energy reserve and habitat on the performance of juvenile Balanus amphitrite. The cyprid energy reserve (quantified as total lipid content) increased linearly with increasing food (the diatom Chaetoceros gracilis) concentrations, i.e. cyprids from nauplii fed the highest (1 × 10 6 cells ml -1 ), high (5 × 10 5 cells ml -1 ), low (1 × 10 5 cells ml -1 ) and the lowest (5 × 10 4 cells ml -1 ) food concen- trations had the highest (0.81 µg cyprid -1 ), high (0.65 µg cyprid -1 ), low (0.45 µg cyprid -1 ) and the lowest (0.18 µg cyprid -1 ) energy reserves, respectively. These cyprids were induced to metamorphose in the laboratory and then transplanted to 4 field sites differing in food availability. Their perfor- mance (measured as growth and survival) was assessed on Day 6. Regardless of the site, both survival and growth were lower for juveniles obtained from cyprids with the lowest energy reserve compared with juveniles obtained from cyprids with low, high and the highest energy reserves. However, the magnitude of the effect of cyprid energy reserve on growth varied among sites. For example, juve- niles obtained from cyprids with the lowest energy reserve grew larger (~2- to 3-fold) at sites with a high chlorophyll a and low C/N ratio (indicators of surplus and high-quality food) than their siblings at other sites. This was interpreted as the result of the interaction between the negative effects of the lowest energy reserve in cyprids and the positive effect of surplus food. Adverse effects of the lowest energy reserve in cyprids on juvenile growth, however, could not be completely compensated by sur- plus food. Regardless of the cyprid energy reserve, juvenile growth (not survival) increased as chloro- phyll a increased. This study suggests that the in situ growth of juvenile barnacles may depend on both independent and interactive effects of cyprid energy reserve (larval nutritional condition) and habitat.