The behaviour of giant clams (Bivalvia: Cardiidae: Tridacninae)

Giant clams, the largest living bivalves, live in close association with coral reefs throughout the Indo-Pacific. These iconic invertebrates perform numerous important ecological roles as well as serve as flagship species—drawing attention to the ongoing destruction of coral reefs and their associated biodiversity. To date, no review of giant clams has focussed on their behaviour, yet this component of their autecology is critical to their life history and hence conservation. Almost 100 articles published between 1865 and 2014 include behavioural observations, and these have been collated and synthesised into five sections: spawning, locomotion, feeding, anti-predation, and stress responses. Even though the exact cues for spawning in the wild have yet to be elucidated, giant clams appear to display diel and lunar periodicities in reproduction, and for some species, peak breeding seasons have been established. Perhaps surprisingly, giant clams have considerable mobility, ranging from swimming and gliding as larvae to crawling in juveniles and adults. Chemotaxis and geotaxis have been established, but giant clams are not phototactic. At least one species exhibits clumping behaviour, which may enhance physical stabilisation, facilitate reproduction, or provide protection from predators. Giant clams undergo several shifts in their mode of acquiring nutrition; starting with a lecithotrophic and planktotrophic diet as larvae, switching to pedal feeding after metamorphosis followed by the transition to a dual mode of filter feeding and phototrophy once symbiosis with zooxanthellae (Symbiodinium spp.) is established. Because of their shell weight and/or byssal attachment, adult giant clams are unable to escape rapidly from threats using locomotion. Instead, they exhibit a suite of visually mediated anti-predation behaviours that include sudden contraction of the mantle, valve adduction, and squirting of water. Knowledge on the behaviour of giant clams will benefit conservation and restocking efforts and help fine-tune mariculture techniques. Understanding the repertoire of giant clam behaviours will also facilitate the prediction of threshold levels for sustainable exploitation as well as recovery rates of depleted clam populations

Recruitment Constraints in Singapore's Fluted Giant Clam (Tridacna squamosa) Populations - A Dispersal Model Approach

10.1371/journal.pone.0058819PLoS ONE83

The effects of golimumab treatment on systolic and diastolic left ventricular function in ankylosing spondylitis

SC Heslinga,1,2 TC Konings,3 IE van der Horst-Bruinsma,1,2 O Kamp,3 VP van Halm,3,4 HACM de Bruin-Bon,4 MJ Peters,5 MT Nurmohamed1,2 1Department of Rheumatology, Amsterdam Rheumatology and Immunology Center, Reade, Amsterdam, The Netherlands; 2Department of Rheumatology, Amsterdam Rheumatology and Immunology Center, VU University Medical Center, Amsterdam, The Netherlands; 3Department of Cardiology, VU University Medical Center, Amsterdam, The Netherlands; 4Department of Cardiology, Academic Medical Center, Amsterdam, The Netherlands; 5Department of Internal Medicine, VU University Medical Center, Amsterdam, The Netherlands Background: Diastolic left ventricular (LV) dysfunction appears more prevalent in ankylosing spondylitis (AS). The effects of tumor necrosis factor alpha (TNF-α) blocking therapy, a strong and effective anti-inflammatory drug, on diastolic LV function in AS are unknown. The objective of the study was to find the effects of 1-year treatment with golimumab 50 mg subcutaneously once per month on systolic and diastolic LV dysfunction in AS patients.Methods: Forty consecutive AS patients were treated with TNF-α blocking therapy for 1 year. Transthoracic echocardiography was performed in all patients at baseline and after 1 year of treatment.Results: Diastolic LV function improved after treatment in four out of six (67%) AS patients who completed follow-up (P=0.125), and did not develop or worsen in any of the other patients. Treatment with TNF-α blocking therapy had no effect on systolic LV function.Conclusion: These findings give support to the hypothesis that diastolic LV dysfunction improves during treatment with TNF-α blocking therapy. Keywords: ankylosing spondylitis, cardiovascular disease, anti-TN

Can artificial substrates enriched with crustose coralline algae enhance larval settlement and recruitment in the fluted giant clam (Tridacna squamosa)?

10.1007/s10750-008-9698-0Hydrobiologia625183-90HYDR