Skip to main content
Figure 2 | Frontiers in Zoology

Figure 2

From: Developmental dynamics of myogenesis in the shipworm Lyrodus pedicellatus (Mollusca: Bivalvia)

Figure 2

Confocal micrographs showing myogenesis in four subsequent early larval phases of Lyrodus pedicellatus . Scale bars represent 20 μm, except in D, in which it equals 50 μm. All aspects are in lateral view, C is slightly tilted in anterodorsal direction. Anterior is upwards in all aspects. Ventral is to the left, except in A, where it is to the right. (A) Earliest veliger stage investigated, showing two muscle bundles of the paired ventral larval retractors (vlr) and a pair of ventral (vvr) and dorsal velum retractors (dvr), which extend into the velum (v). The anterior adductor muscle (aa), divided into two bundles, is visible in the dorsal position of the larva and the mantle musculature (mm) surrounds the mantle margin. (B) Early veliger with the velum ring musculature (vrm) and first muscle fibres of the paired foot retractor (fr). Note that the pair of ventral velum retractors now each consists of two parallel muscle bundles. (C) Marginally more advanced veliger than the specimen shown in B with fibres of the left and right foot retractor fusing in the median plane. (D) Mid-veliger with accessory velum retractor (avr) that is attached to the outer surface of the anterior adductor and spreads into the velum. The foot retractor elongates along the median plane. At the ventral side of the velum, a muscle grid (oral velum musculature; ovm) that has formed contact to the velum ring musculature and to the first fibers of the pedal plexus (pp) develops in the postoral region. Note the distinct separation of the pedal plexus and the foot retractors.

Back to article page