77
et al. 2003 ). It is well established that even minor changes in mineral content can
have drastic effects on material properties in hard tissues. For example, those materials with less mineral are weaker and less stiffer than those with larger mineral
content. As reviewed by Porter et al. ( 2007 ), “a biological example of this relationship
is the rostrum of the Blaineville’s beaked whale Mesoplodon densirostris , which is
composed of 96 % mineral, resulting in an incredibly stiff material (46 GPa). The
fi n whale Balaenoptera physalus tympanic bulla has 14 % less mineral, and is 35 %
less stiff,” (Porter et al. 2007 ). Interestingly, in numerous representatives of the
beaked whales ( Ziphiidae ), so called mesorostral cartilage begins to ossify with the
attainment of sexual maturity (Cozzi et al. 2010 ). This type of cartilage is homologous to the cartilaginous nasal septum of all mammals and determines the development of a very dense and compact bone due to ossifi cation in Ziphiidae family (Zotti
et al. 2009 ).
Interest in biomechanical and materials properties of both non-mineralized and
mineralized cartilages of marine fi sh and mammals origin as model organisms is
very high. What is the mechanical function of cartilage? According to Mansour
( 2004 ), the compliance of this biological material helps to distribute the loads, for
example, between opposing bones in a synovial joint specifi cally. If cartilage were
a bone-like strong material, the area of contact would be much smaller, however, the
contact stresses at a joint would be much higher.
Cartilaginous fi shes perform at functional extremes, below are some examples.
Thus, some species of suction-feeding sharks feed on prey using the generation of
suction pressure that is determined by the ceratohyal cartilage. Usually, this type of
cartilage supports the “tongue” and is made by a pair of rod-shaped cartilages. It
articulates with the hyomandibular cartilage at its proximal end, and with the
basihyal cartilage at its distal end (Tomita et al. 2011 ). As observed by Tomita and
co- workers, “the ceratohyal cartilages rotate around the hyomandibuloceratohyal
articulations ventrally just after opening the mouth during prey capture. The hyoid
arch is depressed and the tongue depresses, resulting in an increase in volume of the
oral cavity which generates suction pressure.” Correspondingly, the hyoid depression is based on activity of special muscles which connect the basihyal cartilage and
the pectoral girdle. These muscles, also known as coracohyoideus coupling (Wilga
et al. 2000 ) contain the coracoarcualis and the coracohyoideus . Their function is
described in following way: “by shortening the coracohyoideus coupling, the basihyal cartilage is pulled posteriorly and the hyoid arch rotates ventrally, expanding
the oral cavity. At this time, negative pressure is generated in the oral cavity, and
suction-feeding sharks use this negative pressure to suck in the prey into front of its
mouth” (Tomita et al. 2011 ). It was reported by (Motta et al. 2008 ) that contraction
forces of the coracohyoideus coupling are able to generate the negative pressure in
the oral cavity in the nurse shark Ginglymostoma cirratum up to 2,100 kPa. It was
hypothesized that stronger suction feeders are expected to have stronger contraction
forces of the coracohyoideus coupling because they generate larger negative pressures. It was confi rmed (Tomita et al. 2011 ) that “the stiffness of the ceratohyal
cartilage is positively correlated with suction feeding”.
2.1 From Non-mineralized to Mineralized Cartilage
et al. 2003 ). It is well established that even minor changes in mineral content can
have drastic effects on material properties in hard tissues. For example, those materials with less mineral are weaker and less stiffer than those with larger mineral
content. As reviewed by Porter et al. ( 2007 ), “a biological example of this relationship
is the rostrum of the Blaineville’s beaked whale Mesoplodon densirostris , which is
composed of 96 % mineral, resulting in an incredibly stiff material (46 GPa). The
fi n whale Balaenoptera physalus tympanic bulla has 14 % less mineral, and is 35 %
less stiff,” (Porter et al. 2007 ). Interestingly, in numerous representatives of the
beaked whales ( Ziphiidae ), so called mesorostral cartilage begins to ossify with the
attainment of sexual maturity (Cozzi et al. 2010 ). This type of cartilage is homologous to the cartilaginous nasal septum of all mammals and determines the development of a very dense and compact bone due to ossifi cation in Ziphiidae family (Zotti
et al. 2009 ).
Interest in biomechanical and materials properties of both non-mineralized and
mineralized cartilages of marine fi sh and mammals origin as model organisms is
very high. What is the mechanical function of cartilage? According to Mansour
( 2004 ), the compliance of this biological material helps to distribute the loads, for
example, between opposing bones in a synovial joint specifi cally. If cartilage were
a bone-like strong material, the area of contact would be much smaller, however, the
contact stresses at a joint would be much higher.
Cartilaginous fi shes perform at functional extremes, below are some examples.
Thus, some species of suction-feeding sharks feed on prey using the generation of
suction pressure that is determined by the ceratohyal cartilage. Usually, this type of
cartilage supports the “tongue” and is made by a pair of rod-shaped cartilages. It
articulates with the hyomandibular cartilage at its proximal end, and with the
basihyal cartilage at its distal end (Tomita et al. 2011 ). As observed by Tomita and
co- workers, “the ceratohyal cartilages rotate around the hyomandibuloceratohyal
articulations ventrally just after opening the mouth during prey capture. The hyoid
arch is depressed and the tongue depresses, resulting in an increase in volume of the
oral cavity which generates suction pressure.” Correspondingly, the hyoid depression is based on activity of special muscles which connect the basihyal cartilage and
the pectoral girdle. These muscles, also known as coracohyoideus coupling (Wilga
et al. 2000 ) contain the coracoarcualis and the coracohyoideus . Their function is
described in following way: “by shortening the coracohyoideus coupling, the basihyal cartilage is pulled posteriorly and the hyoid arch rotates ventrally, expanding
the oral cavity. At this time, negative pressure is generated in the oral cavity, and
suction-feeding sharks use this negative pressure to suck in the prey into front of its
mouth” (Tomita et al. 2011 ). It was reported by (Motta et al. 2008 ) that contraction
forces of the coracohyoideus coupling are able to generate the negative pressure in
the oral cavity in the nurse shark Ginglymostoma cirratum up to 2,100 kPa. It was
hypothesized that stronger suction feeders are expected to have stronger contraction
forces of the coracohyoideus coupling because they generate larger negative pressures. It was confi rmed (Tomita et al. 2011 ) that “the stiffness of the ceratohyal
cartilage is positively correlated with suction feeding”.
2.1 From Non-mineralized to Mineralized Cartilage