Beyond their commercial importance for LAL and bait, and their status as a living fossil, it is often asserted that horseshoe crabs play a vital role in the ecology of estuarine and coastal communities. How would the various ecological relationships involving horseshoe crabs be affected if these animals were no longer abundant? Attempts to understand and generalize the ecological importance of ...

To discern the position of horseshoe crabs as a potentially important predator in estuarine food webs, we determined where they foraged and what they ate. We used N and C stable isotopes to link adult horseshoe crabs to their foraging locations and potential food sources in Pleasant Bay, Cape Cod. The dN in tissues of horseshoe crabs and their potential foods suggest crabs were loyal to local f...

A cationic peptide, designated tachyplesin, was isolated from acid extracts of horseshoe crab (Tachypleus tridentatus) hemocyte debris. It consists of 17 residues and the structure determined by Edman degradation is: (formula; see text) The carboxyl-terminal end of this peptide was identified as arginine alpha-amide, and the whole sequence including the alpha-amide was also confirmed by fast at...

It is well established that horseshoe crab eggs can develop successfully across a wide range of temperatures and salinities. However, many estuaries in which horseshoe crabs spawn have been heavily impacted by pollutants, and degraded water quality may be affecting the survival of horseshoe crab eggs laid in such areas. Laboratory bioassays using Limulus polyphemus embryos and larvae have shown...

Concern has been raised about the ability of horseshoe crabs Limulus polyphemus to traverse intertidal rack-and-bag oyster farms, and how farms may change shorebird foraging activity. During the 2016 horseshoe crab spawning season, experiments conducted in Delaware Bay (New Jersey, USA) assessed the ability of crabs to move among oyster farms and access landward nesting grounds, and surveyed th...

Horseshoe crabs have been a model for many biomedical science studies. Medicinal value of horseshoe crabs comes from its blue blood, eye and exoskeleton (chitin). Ability of blood to clot in the presence of bacteria, rendering the bacteria harmless has created its biomedical importance. Blood cells (amebocytes) carry Factor C, which binds lipopolysaccharide (LPS), undergoes a structural reorgan...

Light and electron microscopy and in vitro inflation experiments were conducted on the aortae of three different invertebrate species: the lobster Homarus americanus, the horseshoe crab Limulus polyphemus and the whelk Busycon contrarium. Inflation experiments were also performed on the aortae of two species of primitive vertebrates, the sea lamprey Petromyzon marinus and the Atlantic hagfish M...

Avian influenza viruses (AIVs) pose significant danger to human health. A key step in managing this threat is understanding the maintenance of AIVs in wild birds, their natural reservoir. Ruddy turnstones (Arenaria interpres) are an atypical bird species in this regard, annually experiencing high AIV prevalence in only one location-Delaware Bay, USA, during their spring migration. While there, ...

Horseshoe crabs' exceptional morphological conservatism over the past 150 My has led to their reputation as "living fossils," but also has served to obscure phylogenetic relationships within the complex. Here we employ nucleotide sequences from two mitochondrial genes to assess molecular evolutionary rates and patterns among all extant horseshoe crab species. The American species Limulus polyph...