Apically directed finger-like projections or ctenidia
present on the surface of the dorsal stylets helped to hold the egg in position (Rogers, 1972) as well as to stop the backward movement of the egg during oviposition process (Boring, 2010).
The association between the ctenidia
and labial palps belongs to category I of Stasek (1963) in which the anterior filaments of the inner demibranch are inserted but not fused with the anterior canal.
Abdomen: 2 short, pointed ctenidia
ventrally on fourth abdominal sternite (Fig.
polymorpha was attributed to a higher CE for the bacteria and a higher pumping rate, a consequence of a higher number of laterofrontal cirri and larger ctenidia
, respectively, in this mussel compared with the other two species.
In the tail region, the ventral and lateral nerve cords finally form a continuous loop as the suprarectal ganglion, from which the nerves for ctenidia
and posterior organs are derived (Fig.
Etymology.--From the Spanish for trowel, paleta, which refers to the shape of the four ctenidia
. To be treated as a noun in apposition.
This may be the result of detrimental organismal responses associated with excessive food concentrations, including reduced food handling rates resulting from overloaded ctenidia
(Kahlil 1996, Riisgard et al.
Endosymbionts observed on histological examination included Rickettsia-like organisms (RLOs) in the ctenidia
(n = 246); an unidentified metazoan parasite in the siphon epithelium (n = 220); and microsporidia-like species in the intestine (n = 103), siphon muscle (n = 28), and ova (a Steinhausia-Wke parasite; n = 99).
Particle velocities (outer demibranch lamellae, 90 [macro]n [s.sup.-1]; inner demibranch lamellae, 129 [macro]m [S.sup.-1]; marginal food groove of inner demibranchs, 156 [macro]m [S.sup.-1]; dorsal ciliated tracts, 152 [macro]m [S.sup.-1]), as well as the movement of particles on the ctenidia
and labial palps of D.
Giant clam ctenidia
or gills were examined for histological abnormalities.
Diagnosis: Aplacophoran molluscs with a narrow foot-fold in a ventral, longitudinal pedal groove and without a cuticular oral shield or mantle cavity ctenidia
; midgut as a combined stomach and digestive gland; monoecius.
Such resolution may also help account for adaptive adjustments in efficiencies of retention on the ctenidia
(Stenton-Dozey & Brown 1992, Barille et al.