PALM WORM MUCUS: ACCUMULATION OF MINERALS AND TRACE ELEMENTS 



The Alvinellidae is a new polychaete family known 

 exclusively from hydrothermal vents (Desbruyeres and Laubier 

 1986). The palm worm, Paralvinella palmiformis (Desbruyeres and 

 Laubier), is an alvinellid found in large numbers at most 

 hydrothermal vents in the northeast Pacific. It has a very 

 flexible life habit, adopting a semi-erect posture with its 

 caudal end coiled around vestimentiferan tubes, freely ranging 

 over surfaces of sulfide chimneys, living partially buried in 

 sulfide sediments; it also dwells in muco-particulate tubes on 

 the sides of high temperature smokers much like the pompeii worm 

 of East Pacific Rise vents (Desbruyeres and Laubier 1980). 

 Common to all these modes of life is the secretion of large 

 quantities of mucus that has the effect of clearing the worm's 

 epidermal surface of mineral particles that constantly 

 precipitate in the vent environment (Fig. 6a). A protective 

 barrier of mucus remains at all times on the epidermal surface. 

 As mineral particles accumulate a layer of mucus is shed and 

 replaced by newly secreted material (Juniper et al . 1986). Three 

 states of mucus alteration are identifiable in situ and in 

 submersible grab samples of vent fauna (Fig. 6a): (1) a 

 transparent layer of freshly produced mucus with no visible 

 mineral accumulations; (2) a bright yellow layer of mucus 

 containing oxidized iron and large quantities of elemental 

 sulfur; and (3) thick grey or grey-black wrappings of mineral- 

 laden mucus in the process of being shed by the worm. Shed mucus 

 is highly insoluble in seawater and persists for significant 

 periods of time in the vent environment where it continues to 

 accumulate mineral particles, likely until it is incorporated 

 into growing mineral deposits (Juniper et al . 1986, Juniper 

 1988). It adheres to vestimentiferan tubes (Fig. 6a) and 

 sulfides. Remarkably large quantities of shed mucus have been 

 recovered with vent faunal grab samples. Approximately 25 

 percent of a 2 kg (wet wt. ) biomass sample from a vent on Axial 

 Seamount consisted of palm worm mucus (Tunnicliffe et al. 1985). 



Mineral Particle Accumulation 



Organic matter generally comprises less than 10% of the 

 total mass of shed mucus. The most significant components are 

 elemental sulfur and mineral particles (Fig. 6b). Samples 

 containing up to 60% elemental sulfur are not uncommon (Juniper 

 et al. 1986, Juniper unpublished data). The origin of the mucus 

 elemental sulfur is not known. Histological examination has so 

 far failed to reveal internal sulfur accumulation in the worm or 

 evidence of sulfur transport to the epidermal surface. A direct 

 linear relationship between mucus carbon and sulfur contents 

 (Juniper et al. 1986) suggests that an organic/elemental sulfur 

 matrix develops before or soon after the mucus is secreted. The 

 carbon and sulfur contents are progressively diluted as mineral 

 particles are occluded, to the point where the material no longer 



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