Sepia officinalis, Linnaeus, 1758

Wild, Elvira, Wollesen, Tim, Haszprunar, Gerhard & Heß, Martin, 2015, Comparative 3 D microanatomy and histology of the eyes and central nervous systems in coleoid cephalopod hatchlings, Organisms Diversity & Evolution (New York, N. Y.) 15 (1), pp. 37-64 : 40

Sepia officinalis

The adult-like hatchling of S. officinalis ( Fig. 11 , supplement interactive Fig. 1 ) is the biggest of the studied specimens (horizontal head diameter ca. 3.5 mm), and therefore, it has the biggest eyes and nervous system (Fig. 2a, supplement “Volumetric analysis” Table 1). As a representative of the Decabrachia, S. officinalis possesses eight arms and two tentacles. The arms are arranged in a circle around the mouth opening and the buccal mass ( Fig. 11b, c ), whereas the tentacles run between arm pairs 3 and 4. They are retractable in a tentacular pocket formed by a skinny duplicature of the integument between the bases of arms 4 and 3 and below the eye chamber ( Fig. 11c–f ). Arm pair 4 possesses lateral

Figures

Fig. 11 Sepia officinalis hatchling: histology of the head region (transversal sections; Richardson staining; see also interactive supplementary figure 1). a Overview with selected planes B-H (3D recon- struction; left side view). b Brachial crown with arms and tentacles. c Base of brachial crown near mouth opening. d Midline of eyes, buccal mass, and anterior funnel. e Lobus opticus just behind the eyes. f Central lobus opticus with optic commis- sure. g Posterior lobus opticus, statocysts with statoliths. h Palliovisceral lobes just behind the lobus opticus. Labels: a 1–4= arms 1–4, abl=anterior basal lobe, aco=anterior chamber or- gan, asg=anterior salivary gland, bl=brachial lobe, bm=buccal mass, cc=cerebral connective, dg=digestive gland, es=esopha- gus, ey=eye, fu=funnel, le=lens, mbl=median basal lobe, mcl= magnocellular lobe, np=pallial nerve, oc=optic commissure, of= olfactory organ, ol=optic lobe (medullar core), opl=outer plexi- form layer, pdc=peduncle com- missure, pl=pedal lobe, psd= posterior salivary duct, psg=pos- terior salivary gland, pvl=palliovisceral lobe, ra=radu- la, rc=radula cartilage, re=retina, sl=statolith, st=statocyst, t=tentacle, tp=tentacular pocket, vtl=vertical lobe

Fig. 1 Midsagittal section through a cephalopod-coleoid central nervous system with its main neuropils (Loligo vulgaris). a Profiles of subesophageal and supraesophageal masses with neuropils (light gray) and perikaryal layers (dark gray)(compare, e.g., with Novicki et al. 1990, Fig. 14). b Digital YZ-reslice with labeled neuropils (2D). c Digital YZ-reslice with labeled neuropils (3D, same colors as in b). Labels: abl=anterior basal lobe, bl=brachial lobe, dbl=dorsal basal lobe, es=esophagus, ifl=inferior frontal lobe, mbl=median basal lobe, pcl=precommissural lobe, pdc=peduncle commissure, pl= pedal lobe, pvl=palliovisceral lobe, sfl=superior frontal lobe, svl= subvertical lobe, vtl=vertical lobe