Euprymna parva Sanchez &amp; Jolly &amp; Reid &amp; Sugimoto &amp; Azama &amp; Marlétaz &amp; Simakov &amp; Rokhsar 2019, comb. nov.
Creators: name: Sanchez, Gustavo
name: Jolly, Jeffrey
name: Reid, Amanda
name: Sugimoto, Chikatoshi
name: Azama, Chika
name: Marlétaz, Ferdinand
name: Simakov, Oleg
name: Rokhsar, Daniel S.
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Cephalopoda
Sepiolida
Sepiolidae
Euprymna
Euprymna parva

description: <i>Euprymna parva</i> (Sasaki, 1913), comb. nov. (Figure 1c left, Table 1, Supplementary Figs. 1, 2c, d, Supplementary Table 2). <i>Sepiola parva</i> Sasaki, 1913: 252, Fig. 4. — Sasaki, 1929: 136–137 Pl. XV, Figs. 4 and 5, text Fig. 80; Takayama and Okutani, 1992: 203–214, fig, 2, Figs. 4–6. — Okutani, 1995: 45, fig. 43. Reid and Norman, 1998: 717. — Reid and Jereb, 2005: 165–166, fig. 239. <i>Inioteuthis parva</i> Sasaki, 1914: 595, pl. 11 Figs. 9 and 10. Type locality: Japan, Tokyo Bay. <b>Material examined</b>. 3 <b>&amp;male;</b> (8.5–10.7 mm ML), 3 <b>&amp;female;</b> (7.0–8.0 mm ML), East China Sea, Okinawa, Diamond Beach in Seragaki, 26.51N, 127.88E, &lt;2 m, 15 June 2016, coll. J. Jolly, G. Sanchez, A. Masunaga &amp; K. Asada (AM C.574777, Hap 3, and GenBank accession number: LC417215). <b>Remarks</b>. The correct generic placement of this taxon has been equivocal since it was first described. It was first placed in <i>Sepiola</i>, transferred to <i>Inioteuthis</i> Sasaki, 1914, then later retained in the genus <i>Sepiola</i>. Sasaki does not explain why <i>parva</i> was placed in <i>Sepiola</i> in his 1929 treatise, nor why it was referred to <i>Inioteuthis</i> in his 1914 work. Clearly, however, the features noted by Sasaki, <b>6</b> (2019) 2:465 | https://doi.org/10.1038/s42003-019-0661-6 | www.nature.com/commsbio “the nipple-like protruberance” near the base of the hectocotylus and the “peculiar and unstalked cylindrical suckers” (Sasaki48: 137) are characteristic of <i>Euprymna</i>. Mature males have two rows of suckers on their arms, in contrast to the four rows typically (but not always) found among <i>Euprymna</i>. This has, no doubt, resulted in its misplacement in the genus <i>Sepiola</i>, that has continued largely without question until now. However, two rows of arm suckers are also found in <i>E. pardalota</i> and <i>E. phenax</i>. The inclusion of the <i>E. pardalota</i> COI sequence in our analyses (Fig. 2) confirms its position, and that of “ <i>Sepiola</i> ” <i>parva</i> in the monophyletic genus <i>Euprymna</i>. Optic lobe transcriptome data (Fig. 3) clearly places <i>S. parva</i> in the monophyletic <i>Euprymna</i> clade, and the pairwise synonymous substitution rate (Ks) between clades (Supplementary Fig. 1) highlights the disjunction between <i>Euprymna</i> and <i>Sepiola</i>, providing strong support for their distinct generic status. The genetic distance data fully supports the placement of <i>S. parva</i> in the genus <i>Euprymna</i> and this evidence now permits a more robust definition of the genus based on morphological characters. The hectocotylus (dorsal left arm) of <i>Euprymna</i> is unique among the Sepiolinae. In all genera but <i>Euprymna</i>, the hectocotylus is clearly tripartite, with a morphologically distinct basal part, copulatory apparatus, and distal part49,50. In contrast, in <i>Euprymna</i>, the hectocotylized arm has a bipartite form, with a proximal portion and a distal modified part. In <i>Euprymna</i> there is no distinct copulatory apparatus, instead the pedicels of the ventral suckers in the third to fourth proximal rows are modified to form 1–2 papillae in most species, sometimes bearing a vestigial sucker, whereas in all other genera the sucker pedicels forming the copulatory apparatus are more conspicuously modified (mostly horn- or hook-like). More importantly, the distal-most portion of the <i>Euprymna</i> hectocotylus bears deeply modified sucker-stalk elements: the stalks are columnar, i.e., thickened and lengthened, and appressed to each other to form palisades, and the sucker proper is reduced to a small opening surrounded by a chitinous rim, often covered by a fleshy cap and embedded in the columnar pedicel. On the contrary, in all other genera, the hectocotylus distal suckers are normal (in some cases some of them may be enlarged and/or their stalks slightly <b>c</b> Male arm crown, dorsal view, holotype 14.9 mm ML (NSMT Mo 85885), scale bar 5 mm. <b>d</b> Female right side (of animal) arm crown, oral view, paratype, 15.3 mm ML (NSMT Mo 85893), scale bar 2 mm. <b>c</b>, <b>d</b> Numbers 1 <b>–</b> 4 indicate Arms 1 <b>–</b> 4. <b>e</b> SEM Arm 4 sucker rim, paratype female, 19.5 mm ML (NSMT Mo 85889), scale bar 20 µm. <b>f</b> SEM enlargement of sucker rim shown in (<b>d</b>), scale bar 10 µm. lengthened) (Bello, submitted). The very simple copulatory apparatus of <i>Euprymna</i> is considered a plesiomorphic character state 51 in the Sepiolinae, placing this genus in a basal position within the subfamily36,52.
description: Published as part of <i>Sanchez, Gustavo, Jolly, Jeffrey, Reid, Amanda, Sugimoto, Chikatoshi, Azama, Chika, Marlétaz, Ferdinand, Simakov, Oleg &amp; Rokhsar, Daniel S., 2019, New bobtail squid (Sepiolidae: Sepiolinae) from the Ryukyu islands revealed by molecular and morphological analysis, pp. 1-15 in Communications Biology 2 (465)</i> on pages 6-7, DOI: 10.1038/s42003-019-0661-6, http://zenodo.org/record/3723016
description: {"references": ["55. Sasaki, M. Decapod cephalopods found in Japan (Sepiolidae). 25 (Tokyo Dobutsu Gakkai, 1913).", "48. Sasaki, M. A monograph of the dibranchiate cephalopods of the Japanese and adjacent waters. J. Coll. Agric. Hokkaido Univ. 20, 1 - 357 (1929).", "53. Reid, A. &amp; Jereb, P. Family Sepiolidae. In P. Jereb &amp; C. F. E. Roper eds. Cephalopods of the world. An annotated and illustrated catalogue of cephalopod species known to date. Vol. 1. Chambered nautiluses and sepioids (Nautilidae, Sepiidae, Sepiolidae, Sepiadariidae, Idiosepiidae and Spirulidae). pp. 153 - 203 (FAO Species Cat. Fish. Purp. Rome, 2005)."]}