Respiration rates for the intertidal spiderDesis marina(Hector)

Abstract

Respiration experiments involving the intertidal spider Desis marina (Hector) yielded a respiration ( Il~ h-' ) -weight (mg) relationship of 10g,oR = 0.6110g1OW -0.61 at 17SC; which is much lower ( < 50%) than the rates obtained for terrestrial spiders. D. marina was also able to survive until oxygen partial pressures fell to 18-24 mmHg (12% of ambient levels). These 2 features help explain how D. marina are able to withstand long periods of submergence in bull kelp holdfasts on the shore. Calculations and experiments involving air spaces which did not contain spiders both suggested that the 'physical gill effect' should provide enough oxygen to ensure > 100 days underwater survival for even the largest animals. However, survival and respiration experiments suggested that the spiders 'conditioned' their environment so that the physical gill effect was reduced to providing only 3 -10% (depending upon weight) of the required oxygen.

Phylogeography of Australian and New Zealand spray zone spiders (Anyphaenidae:Amaurobioides): Moa's Ark loses a few more passengers

“…Even if the retreat were submerged, its silk closure membrane, and perhaps also its thicker silk wall, would allow oxygen exchange with the seawater, as reported for members of the genus Desis (family Desidae) that construct silk retreats in the intertidal zone and can remain submerged for several days during extreme tides (being supplied with oxygen that diffuse into their retreats). (Lamoral, 1968;McQueen, Pannell & McLay, 1983;McLay & Hayward, 1987). This hypothesis may also explain why Amaurobioides, with their apparently good dispersal capabilities, are restricted to the cool southern coasts.…”

“…Moreover, when ballooning does occur, it typically accounts for a dispersal distance of only a few hundred kilometers in spiders (Gillespie et al, 2012). (Lamoral, 1968;McQueen, Pannell & McLay, 1983;McLay & Hayward, 1987). A female that has produced an egg sac in her retreat and sealed its entrance with a silk membrane (Opell, 2010) should be able to survive for an extended period of time at sea, particularly in cold waters that both lower her metabolism and slow the development of her eggs.…”

The complete mitochondrial genome of the intertidal spider (Desis jiaxiangi) provides novel insights into the adaptive evolution of the mitogenome and the evolution of spiders

“…The hydrofuge hairs on the bodies of aquatic spiders can form a thin air film, which enables them to use a physical gill or plastron respiration to exchange oxygen and carbohydrates [29,31]. Meanwhile, Desis marina has lower respiration rates than other spider species [17]. In general, many organisms highly diverged in the opposite osmotic pressures a b…”

“…Desis spiders inhabit intertidal zones at the junction of sea and land. Although they have a fascinating habitat [16,17] and have been subject to taxonomic study [18,19], there is limited molecular research on this lineage [20]. Desis spiders are mainly found along the coast of warmer seas in Australia, Brazil, China, Galapagos, India, Japan, New Zealand, Polynesia, and South Africa [19].…”

Spidroins and Silk Fibers of Aquatic Spiders

“…While D. marina is found in marine habitats, A. aquatica (Dictynidae, Dictynoidea), our third focal species, is found in freshwater ponds and lakes in Northern Europe, spending all of its life underwater 20 . Like D. marina , A. aquatica is ecribellate.…”