A survey on the populations of "Deer Cowries"

in the lower Florida Keys

The observations made on the gastropods of the general area we made reveal that an unusual incident had taken place between April and July of 2015, that killed off the grazing species, as well as the species living in association with soft corals (the Ovulids), which feed on the mucus the corals secrete, as well as the detritus that adheres to them. Lake Okeechobee was reported to having been flooded by heavy rainfalls earlier this year, causing vast amounts of fresh water pouring into the Gulf. This water may have been enriched by fertilizers, pesticides, and other substances that affected the marine biotopes in a more severe than usual manner.

After reporting our findings to the community of snorklers and shell collectors frequently visiting the area since many decades, nobody seemed to have noticed the die-off that we observed. Had the activities of collectors been the cause, we would not have found that many empty shells in pristine condition scattered on the seafloor. Future excursions will hopefully show the incident to be a non-permanent damage to the unique ecosystem of the lower Florida Keys reef tract.

 

The expeditions conducted with the help of the MSF have led to an observation that draws an alarming picture of the condition of worldwide marine habitats. We are witnessing a drastic decline in Gastropod diversity in many places considered "untouched" by civilization, and other places that seemed unaffected by pollution, overfishing, or global warming. This decline can be deduced from the imbalance of the habitats populated by those gastropod families we have currently focused on, the Cowries (Cypraeidae), Cones (Conidae), and the Ovulids, also known as spindle- or egg-Cowries (Ovulidae). To monitor their populations could give indications on the condition of marine ecosystems.

The reports just given put an emphasis on molluscan biodiversity and ecological aspects. Now let's look at trips that played an important role in the study of one of the most diverse and important families of seashells:

 

The family Conidae and their Conotoxins

 

Conotoxins constitute a vast group of neurotoxic peptides isolated from the venom of the marine cone snail (Conidae). They are peptides consisting of 10 to 30 amino acid residues. Most of them modulate the activity of ion channels (Terlau et al. 2004, Olivera & Teichert 2007, Livett et al.).

 

Pain therapeutics discovered by molecular mining of the expressed genome of Australian predatory cone snails are providing lead compounds for the treatment of neurological diseases such as multiple sclerosis, shingles, diabetic neuropathy, and other painful neurological conditions. The high specificity exhibited by these novel compounds for neuronal receptors and ion channels in the brain and nervous system indicates the high degree of selectivity that these classes of neuropeptides possess for therapeutic use in humans. A compound, ACV1 (conotoxin Vc1.1 from Conus victoriae), has entered Phase II clinical trials and is being developed for the treatment for neuropathic pain. ACV1 will be targeted initially for the treatment of sciatica, shingles, and diabetic neuropathy. The compound is a 16 amino acid peptide.

 

A novel alpha-conotoxin identified by gene sequencing is active in suppressing the vascular response to selective stimulation of sensory nerves by acting as an antagonist of neuronal nicotinic acetylcholine receptors. It has potent analgesic activity following subcutaneous or intramuscular administration in several preclinical animal models of neuropathic pain. Alpha conotoxin Vc1.1 alleviates neuropathic pain and accelerates functional recovery of injured neurons. ACV1 may act as an analgesic by decreasing ectopic excitation in sensory nerves. In addition, it appears to accelerate the recovery of injured nerves and tissues.

 

Every new species of cone that is being discovered yields a unique combination of concotoxins which may be of importance to medical research. During the three years of cooperation with taxonomists in the laboratory or in the field, more than 20 new species of Conidae have been discovered and made available to science, many of them have already been formally described and examined genetically.

A spectacular discovery made on an expedition conducted prior to the founding of the MSF was a tiny but distinctive member of the Conidae, which was described as Virroconus lecourtorum Lorenz 2011, on the basis of dead and eroded shells.

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