Cardiidae

— Cardiids or marine cockles are one of the best known families of marine bivalves in the world, with a long history of study and collection given their large and accessible shells, a tractable level of biodiversity globally (~290 species) and a solid fossil record extending to the late Triassic. In Western Australia, the cardiids are well known relative to other marine bivalve families, having been the subject of focussed treatment and consist of 31 species. However, given the proximity to the Indo-West Pacific, sheer size of the state and almost unparalleled number of habitats, the diversity is likely underestimated. Over the last 40 years, ongoing expedition work coupled with taxonomic study by the authors, has resulted in a doubling of the cardiid fauna of Western Australia (WA). Current cardiid diversity now stands at 68 species, including seven species of giant clams (Tridacninae). Subfamilial representation has changed little (except for the addition of Tridacninae previously in its own family, the Tridacnidae), and key genera in Cardiinae (e.g. Fulvia), Fraginae (e.g. Fragum) and Trachycardiinae (e.g. Acrosterigma and Vasticardium) still deliver much of the diversity. This updated biodiversity census has implications within and beyond Western Australia, with 16 new species records for the state and 14 new records for Australia, including four new species: Acrosterigma extremattenuatum sp. nov., Ctenocardia pilbaraensis sp. nov., Microcardium scabrosum sp. nov. and Pratulum occidentale sp. nov. Further taxonomic decisions include recognition of Vasticardium serricostatum (Melvill & Standen, 1899) and Lunulicardia tumorifera (Lamarck, 1819) as distinct species. Vasticardium swanae Maxwell, Congdon & Rymer, 2016 is considered a new synonym of Cardium variegatum G.B. Sowerby II, 1840; Vasticardium lomboke Vidal, 2003 is considered a new synonym of Cardium mindanense Reeve, 1844 and Acrosterigma abrolhense Vidal, 1999 is considered a new synonym of Cardium cygnorum Deshayes, 1855. All subspecies in the Vasticardium elongatum (Bruguière, 1789) complex are raised to species level.

New acquisitions arising from tropical survey work in the north have yielded all of the newly added species and all newly described species in the Western Australian Museum (WAM) cardiid collections. This is in contrast to the relatively stable biodiversity of southwestern Western Australia. In the north, diversity is highly structured with sixteen taxa found restricted to offshore islands and shoals (e.g. Vasticardium philippinense (Hedley, 1899), V. elongatum (Bruguière, 1789), Corculum cardissa (Linnaeus, 1758), Ctenocardia fornicata (G.B. Sowerby II, 1840), C. gustavi Vidal & Kirkendale, 2007), and a smaller cohort found exclusively inshore (e.g. A. extremattenuatum sp. nov., V. wilsoni (Voskuil & Onverwagt, 1991), C. pilbaraensis sp. nov.). Biodiversity comparisons are made with other tropical states in northern Australia, including the Northern Territory (NT) and Queensland (Qld), and considered together these records support recognition of a vast Dampierian Province. Regional biogegraphic comparisons are also made to examine whether cardiids in northern Australia are as diverse as other central Indo West Pacific (IWP) areas. To improve management of the commercially important Tridacninae (giant clams), we provide the first formal records of species diversity and distribution in this group for WA. While cardiids are relatively well characterised, persistent gaps remain that are not unique to this family. Our knowledge of small and/or cryptic species, as well as the deep water fauna broadly, lags behind our understanding of shallow water macromolluscs.

"Fulvia (Fulvia) nienkeae spec. nov. (Cardiidae) is described
from various localities in the Central Indo-West Pacific. It is
compared with the similar, sympatric Fulvia (Fulvia) australis
(G.B. Sowerby II, 1834) and with the Pliocene Fulvia (Fulvia)
tegalense (Oostingh, 1934) comb. nov."

Commercial and recreational harvesting of shellfish within the coastal systems is usually very extensive. Since these ecosystems are frequently subjected to contamination, namely from agricultural, urban and industrial activities, and shellfish generally display a high capacity to bioaccumulate metals, populations may be at risk in terms of toxic metal exposure as a consequence of the harvesting and ingestion of near shore coastal marine organisms. Shellfish is regularly tested for concentrations of metals and other contaminants by legal authorities for commercial purposes, but although health officials use total metal as standards of food safety, only a part of the metal accumulated in shellfish is available to be assimilated and to cause toxic effect. In order to elucidate these issues an investigation on cockles inhabiting the Aveiro estuary was conducted. Element levels in sediments and wild Cerastoderma edule from sampling areas with different levels of contamination were measured; total element burden of cockles was related to accessible fraction for assimilation (TAM); element concentrations in wild C. edule were compared to EFSA (European Food Safe Authorities), USFDA (United States Food and Drug Administration) and FSANZ (Food Standards Australia and New Zealand) maximum levels (MLs); and the amount of cockle flesh needed to be consumed to exceed provisional tolerable weekly intake (PTWI) was determined. The present work showed that although sediment metal and metalloid contamination in Aveiro estuary is low the concentration of elements in C. edule does not reflect the contamination of the sediment. Aluminium (Al) and mercury (Hg) were the less and nickel (Ni), lead (Pb), zinc (Zn) and cadmium (Cd) were the most bioaccumulated metals by cockles. Comparison of MLs from international organisations with the concentration of elements in C. edule showed that arsenic (As) and Pb exceeded standard levels. The ingestion of less than 1 kg for As and 1.5 kg for Pb of cockles would result in exceeding the PTWI threshold (0.015 and 0.025 mg kg⁻¹ week⁻¹ respectively) in any of the areas considered in the study. Cd and Al also appear to be limiting elements for human consumption. Indeed, consumption of more than 3.1 kg and 2.1 kg of whole cockle soft part from one of the study areas during a single week would lead to exceedance of the recommended PTWI value for Cd (0.007 mg kg⁻¹ week⁻¹) and Al (7 mg kg⁻¹ week⁻¹) respectively. The health concerns to humans from cockle consumption from Aveiro estuary are discussed.

Dins un cens realitzat el 29/04/2017 a la tanatocenosi de la platja del Barranc d’Irta, dins el parc natural de la Serra homònima, es va recollir un exemplar del bivalve Fulvia fragilis (Forsskål in Niebuhr, 1775), una espècie originària de l’oceà Índic. El 6/10/2012 ja s’havia recollit, també, un únic exemplar a la mateixa platja.
Aquest enregistrament de l’espècie lessepsiana confirma que està arribant a la part occidental de la Mediterrània, afegint arguments a favor de la hipòtesi que apunta cap a la tropicalització d’aquesta mar, un fenomen lligat a un hipòtetic increment de la temperatura de l’aigua, com afirma algun autor (Oliverio, 2000). Aquesta és la primera cita documentada i figurada al Baix Maestrat. D’altra banda, el cens, amb
un esforç de 4 hores, va donar una riquesa de 111 espècies de mol·luscs; de llarg, la platja censada més biodiversa de totes les costes castellonenques.
MOTS CLAU: Mollusca, Bivalvia; Cardiidae, Fulvia fragilis, espècie lessepsiana, canvi climàtic, mar Balear, parc natural de la Serra d’Irta, el Baix Maestrat.
RESUMEN
«Fulvia fragilis (Mollusca: Bivalvia) una inmigrante lessepsiana a la costa del Maestrat». Dentro de un censo realizado el 29/04/2017 a la tanatocenosis de la playa del Barranc d’Irta, situada en el parque natural de la Serra d’Irta, se recogió un ejemplar de bivalvo Fulvia fragilis (Forsskål in Niebuhr, 1775), una especie originaria
del océano Índico. El 6/10/2012 ya se había recogido, también, un único ejemplar a la misma playa. Este registro de la especie lessepsiana confirma que esta llegando a la parte occidental de Mediterráneo, añadiendo argumentos a favor de la hipótesis que apunta hacia la tropicalización de este mar, un fenómeno ligado a un hipótetico
incremento de la temperatura del agua, como afirma algún autor (Oliverio, 2000).
Esta es la primera cita documentada y figurada en el Baix Maestrat. Por otra parte, el censo, con un esfuerzo de 4 horas, dio una riqueza de 111 especies de moluscos; con diferencia, la playa censada con más biodiversidad de las costas de Castelló.
PALABRAS CLAVE: Mollusca, Bivalvia; Cardiidae, Fulvia fragilis, especie lessepsiana,
cambio climático, mar Balear, parque natural de la Serra d’Irta, el Baix Maestrat.
ABSTRACT
«Fulvia fragilis (Mollusca: Bivalvia) a Lessepsian immigrant on the Maestrat coast».
In a census take on the 2017/04/09 in the thanatocoenosis of the Barranc d’Irta beach, in the natural park of the Serra d’Irta, a specimen of the bivalve Fulvia fragilis (Forsskål in Niebuhr, 1775), a species native to the ocean Indian, was collected.
Another single example was also collected on the same beach on the 2012/10/06. This record of the Lessepsian species confirms that it is reaching the western part of the Mediterranean and provides further supporting evidence to the hypothesis that points towards the tropicalization of this sea as one author affirms (Oliverio,
2000). This is the first documented event of this type in the Baix Maestrat. On a more positive note, the census (based on 4 hours total effort) produced a wealth of 111 species of mollusc and is by far the most bio-diverse beach for these species on the coasts of Castelló.
KEY WORDS: Mollusca, Bivalvia; Cardiidae, Fulvia fragilis, Lessepsian species, climate change, Balear sea, natural park of the Serra d’Irta, the Baix Maestrat

There is global concern about heavy metal contamination in the environment. Adverse health effects can be caused by heavy metals in contaminated food and water. Therefore, environmental monitoring studies and risk assessments should be conducted periodically. In this study, we measured levels of Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn in blood cockles (Anadara granosa) collected from three locations in the Upper Gulf of Thailand. Hazard quotients and hazard indices were calculated to evaluate the health risks posed by heavy metals in consumed blood cockles. Heavy metal concentrations in all of the blood cockle samples were lower than the relevant food standards. The hazard quotients and hazard indices were <1 in all three sampling areas, indicating that adverse health effects were not likely to be caused by exposure to heavy metals in blood cockles over a human lifetime.

Poole Harbour is typical of many heavily anthropologically impacted semi-enclosed estuarine coastal areas under pressure from metal pollution across the world. This study examined the physiological significance of metal burdens within that sensitive area, and assessed the potential use of metallothionein (MT) concentrations in two organisms: the common cockle (Cerastoderma edule) and the Mermaid's glove sponge (Haliclona oculata) for mapping the spatial extent of the biological response to metal contamination. A spectrophotometric method was applied for detection of MT in the bivalve, and for the first time to detect MT in sponges. The results show that while some metal concentrations in cockle and sponge tissues and in their surrounding environment (water and sediment) could be related to sources of metal contamination, MT values in the soft tissue of cockles and whole tissue of sponges are not. No relation could be found between MT in both cockles and sponges, and any of the tested metals (As, Cd, Cr, Cu, Pb, Hg, Ni, Ag, Sn, Zn). Furthermore, some of the lowest MT concentrations were detected in heavily polluted areas, indicating that MT concentrations in tested organisms are not exclusively associated with metal concentrations, as other environmental factors could affect induction of this protein. Organisms probably have a high tolerance to metal contamination and chronic exposure to a high level of contamination resulted in developing a variety of detoxification mechanisms. Results indicate that further study of metal stress in this type of ecosystem may need to examine other indicator species and/or apply a different biomonitoring technique.

Fragum vanuatuense spec. nov. (Cardiidae) is described from various localities in the central Indo-West Pacific. It represents the smallest Fragum and is compared with F. grasi Ter Poorten, 2009 and F. sueziense (Issel, 1869), both occurring partly sympatric with F. vanuatuense spec. nov. Figures of the juvenile growth stages of six Fragum species are given for comparison.

Significant differences previously observed in the determination of paralytic shellfish poisoning toxins (PSTs) in oysters using official method AOAC 2005.06 and 959.08 were investigated in detail with regard to possible matrix effects. Method AOAC 2005.06 gave results 2-3 times higher than the mouse bioassay method, 959.08, differences thought to be due to underestimation of PSTs by the mouse bioassay. In order to prove the cause of these large differences, work was conducted here to examine the presence and effects of matrix components on the performance of each of the two assays. A range of oyster, cockle and mussel samples were extracted using the AOAC 959.08 hydrochloric acid (HCl) extraction method and analysed for PSP by both MBA and LC-FLD. In addition, extracts were analysed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) for metals as well as being subjected to a range of nutritional testing methods. Whilst there was no evidence for effect of nutritional component...

The digenean trematode Diphtherostomum brusinae (Stossich, 1888) Stossich, 1903 presents a complex life cycle that may involve more than one intermediate host. The present study represents the first description of the metacercariae from D. brusinae infecting the labial palps of a new intermediate host, Mytilus galloprovincialis, in the Aveiro estuary, Portugal. The morphology of this parasitic stage was studied by light (LM) and scanning electron microscopy (SEM) and some differences were reported (body and sucker sizes, and spine distribution and shape). In this work, the 18S partial region of the ribosomal DNA was sequenced from D. brusinae metacercariae isolated from M. galloprovincialis collected in different localities of the Aveiro estuary. In addition, sequences from the same region of the 18S rDNA were obtained from D. brusinae cercariae and metacercariae, hosted by Nassarius reticulatus and Cerastoderma edule, respectively. No intraspecific polymorphism was detected in the ...

The chronic exposure of benthic organisms to metals in sediments can lead to the development of tolerance mechanisms, thus diminishing their responsiveness. This study aims to evaluate the accumulation profiles of V, Cr, Co, Ni, As, Cd, Pb and Hg and antioxidant system responses of two benthic organisms (Cerastoderma edule, Bivalvia; Nephtys hombergii, Polychaeta). This approach will provide clarifications about the ability of each species to signalise metal contamination. Organisms of both species were collected at the Tagus estuary, in two sites with distinct contamination degrees (ALC, slightly contaminated; BAR, highly contaminated). Accordingly, C. edule accumulated higher concentrations of As, Pb and Hg at BAR compared to ALC. However, antioxidant responses of C. edule were almost unaltered at BAR and no peroxidative damage occurred, suggesting adjustment mechanisms to the presence of metals. In contrast, N. hombergii showed a minor propensity to metal accumulation, only signa...

A local antibiotic delivery system (LADS) with biodegradable drug vehicles is recognized as the most effective therapeutic approach for the treatment of osteomyelitis. However, the design of a biodegradable LADS with high therapeutic efficacy is too costly and demanding. In this research, a low-cost, facile method was used to design vancomycin-loaded aragonite nanoparticles (VANPs) with the aim of understanding its potency in developing a nanoantibiotic bone implant for the treatment of osteomyelitis. The aragonite nanoparticles (ANPs) were synthesized from cockle shells by a hydrothermal approach using a zwitterionic surfactant. VANPs were prepared using antibiotic ratios of several nanoparticles, and the formulation (1:4) with the highest drug-loading efficiency (54.05%) was used for physicochemical, in vitro drug release, and biological evaluation. Physiochemical characterization of VANP was performed by using transmission electron microscopy, Fourier transform infrared spectrosc...

A tetraplex PCR method was developed for simultaneous detection of Vibrio cholerae, V. parahaemolyticus, V. vulnificus and V. mimicus in cockle samples in comparison with conventional culture method. Specific primers targeting ompW of V. cholerae, tl of V. parahaemolyticus, hsp60 of V. vulnificus and sodB of V. mimicus were employed in the same PCR. Detection limit of the tetraplex PCR assay was 104 cfu/ml (400 cfu/PCR reaction) for pure cultures of all four species of Vibrio. In Vibrio spiked cockle samples, the limit of detection after 6 hours enrichment in alkaline peptone water was 1 cfu/10 g of cockle tissue for three Vibrio spp, except for V. mimicus that was 102 cfu/10 g of cockle tissue. When the tetraplex PCR and culture methods were applied to 100 cockle samples, V. parahaemolyticus, V. vulnificus, V. cholerae and V. mimicus were detected in 100, 98, 80 and 9% of the samples by tetraplex PCR and in 76, 42, 0 and 0% by the culture method, respectively. This developed tetrap...

Dynamic energy budget models for growth of individual cockles ( Cerastoderma edule ) and mussels ( Mytilus edulis ) are adjusted and calibrated to the Oosterschelde by formulating and parametrizing their functional responses using an extensive set of field observations. The resulting model predictions fit the observations satisfactorily. Results indicate that food quality and the importance of detritus as a food source are site-specific as well as species-specific. Despite these differences in their calibrated parameter values, both species show a very similar functional response. Compared with other systems, however, the functional responses of mussels in the present study are clearly higher than those of mussels in other systems. This may be explained by the absence of intra-specific competition in the measurement set-up that was used, and therefore supports the idea that the generally small functional response of M. edulis is caused by intra-specific competition.

Negative density-dependence is generally studied within a single trophic level, thereby neglecting its effect on higher trophic levels. The ‘functional response’ couples a predator's intake rate to prey density. Most widespread is a type II functional response, where intake rate increases asymptotically with prey density; this predicts the highest predator densities at the highest prey densities. In one of the most stringent tests of this generality to date, we measured density and quality of bivalve prey (edible cockles Cerastoderma edule ) across 50 km² of mudflat, and simultaneously, with a novel time-of-arrival methodology, tracked their avian predators (red knots Calidris canutus ). Because of negative density-dependence in the individual quality of cockles, the predicted energy intake rates of red knots declined at high prey densities (a type IV, rather than a type II functional response). Resource-selection modelling revealed that red knots indeed selected areas of interm...