Surface Properties of the Skin of the Pilot Whale Globicephala melas

Abstract

On the skin surface of delphinids small biofoulers are challenged to high shear water flow and liquid-vapor interfaces of air-bubbles during jumping. This state of self-cleaning is supported by the even, nano-rough gel-coated epidermal surface of the skin. The present study focussed on the intercellular evolution of gel formation and the chemical composition of the gel smoothing the skin surface of the pilot whale, Globicephala melas, using X-ray photoelectron spectroscopy (XPS) in combination with cryo-scanning electron microscopy (CSM), and transmission electron microscopy (TEM). In the superficial layer of the epidermis, the stratum corneum, intercellular material was shown by electron optical methods to assemble from smaller into larger covalently cross-linked aggregates during the transit of the corneocytes towards the skin surface. XPS measurements showed that the surface of the skin and the intercellular gel included approximately the same amounts of polar groups (especially, free amines and amides) and non-polar groups, corresponding to the presence of lipid droplets dispersed within the jelly material. It was concluded from the results that the gel-coat of the skin surface is a chemically heterogeneous skin product. The advantages of chemically heterogeneous patches contributing to the ablation of traces of the biofouling process are discussed.

Surface modification approaches to control marine biofouling

“…The surface of the pilot whale skin and intercellular gel contain both polar and non-polar groups, and this chemical heterogeneity is thought to produce opposite wettability on the same surface, which could contribute to short and long-term fouling reduction (Baum et al 2003). Biomimetic antifouling technologies based on the multiple defence principles of the pilot whale skin were reported as under investigation (Baum et al 2003). However, there are no published reports of any potential technologies developed directly from this work.…”

“…The skin of the pilot whale also contains a zymogel which hydrolyses the adhesives of settling organisms (Baum et al 2001), whilst attachment into the nano-ridged pores is prevented by heavy enzymatic digestion (Baum et al 2002). The surface of the pilot whale skin and intercellular gel contain both polar and non-polar groups, and this chemical heterogeneity is thought to produce opposite wettability on the same surface, which could contribute to short and long-term fouling reduction (Baum et al 2003). Biomimetic antifouling technologies based on the multiple defence principles of the pilot whale skin were reported as under investigation (Baum et al 2003).…”

Laser-induced patterns on metals and polymers for biomimetic surface engineering

“…Considering adhesion and water species, the pilot whale with its non-stick skin stands out for antibacterial and antifouling applications. 9 Finally, generating colors without dies and colorants but based on structure, as shown by mussel shells 10 , bird feathers or butterfly wings 11 , have already for a multitude of applications, among those are typical diffraction gratings. While the above examples are diverse and stem from many different species they all have one characteristic in common which is their constitution of particular structures on various length scales.…”

Comparison of surface microfouling and bacterial attachment on the egg capsules of two molluscan species representing Cephalopoda and Neogastropoda

“…Similarly, moulting in crustaceans would facilitate the removal of epibionts (Dyrynda 1986). Relatively little is known of the role of physical defenses (Steinberg et al 2001), though surface composition and microtexture can influence the rate of biofouling (Berntsson et al 2000, Steinberg & De Nys 2002, Baum et al 2003.…”

“…Similarly, moulting in crustaceans would facilitate the removal of epibionts (Dyrynda 1986). Relatively little is known of the role of physical defenses (Steinberg et al 2001), though surface composition and microtexture can influence the rate of biofouling (Berntsson et al 2000, Steinberg & De Nys 2002, Baum et al 2003.Biofilms cultivated on inanimate and biological surfaces under laboratory conditions have been studied extensively using a wide range of microscopic techniques (Beech et al 2000), often in combination, to give a clear description of the biofilm. Scanning electron microscopy (SEM) allows morphological examination of biofilms established on surfaces (Beech et al 2000).…”