Fig. 1 in Octopus sinensis d'Orbigny, 1841 (Cephalopoda: Octopodidae): Valid Species Name for the Commercially Valuable East Asian Common Octopus

Fig. 1. Ventral view of a mature male specimen of Octopus sinensis (NSMT Mo 85658), illustrating the paler ventral surface (cf. dorsal surface of the same specimen visible in Figs 2 and 3) and the size and shape of the funnel (F, held in place with a piece of white cord). A sample (S) of muscle tissue was removed prior to fixation, leaving a circular wound just anterior to the funnel. Fig. 2. Dorsal view of the specimen in Fig. 1, showing the difference in lengths of arms 2 and 3 (longer, ending within the region labelled 'Arms 2 and 3' bracketed to the leπ) versus 1 and 4 (clearly shorter, ending within the adjacent bracketed region labelled 'Arms 1 and 4'). The longer arms include arm R3 (the hectocotylus, H), which (typically much shorter than its counterpart, L3) is only just a little longer than arm pairs 1 and 4 (cf. Table 1, and OAI in Table 2). Note also the relative size and shape of the head, body and arms, and the rugose texture caused by the fixed appearance of the patch-and-groove topology of the skin. Fig. 3. View from the right side (body to leπ; arms to right) of the specimen in Figs 1 and 2. The funnel (F) was fixed in an unusual position (here seen pointing ventrally, perpendicular to the main body axis) as a result of damage following removal (before fixation) of a tissue sample (S) for molecular analysis (cf. Fig. 1). The broad extent of the mantle opening can be seen ventrally. Dorsally there is a large, contracted posterodorsal papilla (Ppd) above the right eye, with a smaller one anterodorsally (Pad). The anterodorsal papilla typically is not obvious except in well-fixed specimens. Fig. 4. An example of the appearance of the oral surface of a male Octopus sinensis to show the position of specially enlarged suckers on arms 2 and 3 of each side (most obvious on arms 2, as indicated: suckers #12 and 13 on the leπ, and #13 and 14 on the right). Anterior of animal (Ant.) is to the leπ, so the leπ arms are in the upper half of the figure and the right arms in the lower half. (Neotype specimen NSMT Mo 85659). Fig. 5. End of arm R3 of the specimen in Figs 1–3, showing the robust spermatophore groove (SGr; cf. Fig. 2, H) and small ligula (L). Fig. 6. Diagram of the tip of arm R3 of Octopus sinensis (lot NSMT Mo 85660 specimen IGG 318, ML 168 mm), illustrating the form of the ligula in more detail. Note modest calamus (Cal.) nestled in the hilum at the base of the ligula, and protuberance (Pr.) on the anterior side closely apposed to the region at the end of the spermatophore groove (SGr), covering the base of both ligula and calamus. (Line drawing by Aki Hamamoto). Fig. 7. Diagram of the tip of arm R3 of Octopus vulgaris specimen BMNH 98.5.21.346 (ML 96 mm), showing that the form and size of the ligula are similar to those of the ligula of O. sinensis (as shown in Figs 5 and 6). (Line drawing by Aki Hamamoto)