Cymodoce richardsoniae Nobili, 1906

Khalaji-Pirbalouty, Valiallah, Bruce, Niel L. & Wägele, Johann-Wolfgang, 2013, The genus Cymodoce Leach, 1814 (Crustacea: Isopoda: Sphaeromatidae) in the Persian Gulf with description of a new species, Zootaxa 3686 (5), pp. 501-533 : 518-523

publication ID	https://doi.org/ 10.11646/zootaxa.3686.5.1
publication LSID	lsid:zoobank.org:pub:C24D40BC-38EE-4C0B-9F1B-DD6CF82B34BD
DOI	https://doi.org/10.5281/zenodo.6146048
persistent identifier	https://treatment.plazi.org/id/153187E0-652E-AE0E-FF75-FEEAFC92FBDE
treatment provided by	Plazi
scientific name	Cymodoce richardsoniae Nobili, 1906
status

Treatment

Cymodoce richardsoniae Nobili, 1906 View in CoL

( Figs 12–15 View FIGURE 12 View FIGURE 13 View FIGURE 14 View FIGURE 15 )

Cymodoce richardsoniae Nobili, 1906: 3 View in CoL , figs 19–23.— Torelli, 1930: 307, pl. 9, fig. 8.— Monod, 1937.— Glynn, 1972: 286 – 289, figs 6–7.— Harrison & Holdich, 1984: 381.

Material examined. Neotype (here designated). 3 (11.8 mm), Red Sea, Egypt, 24.04.1913, coll. E. Bannwarth, ( SNM 3480).

Other material. 1 3 (7.0 mm), Rea Sea, 26.11.1912, coll. E. Bannwarth, ( SNM 1027); 2 3 (10.5 mm; 8.5 mm), 1 sub-adult 3 (7.5 mm), 8 ƤƤ (6.5–7.5 mm), Red Sea, coll. E. Rüppell, 1822–1827 ( SNM 927).

Diagnosis. Pleotelson anterodorsal part with 2 prominent longitudinal ridges, each flanked on either lateral side by 3 prominent tubercles; posterior part bearing tuft of dense long simple setae on anterior part of hemispheric dome; pleotelson apex with short apical lobes. Uropod rami extending beyond pleotelsonic apex, exopod dorsomedial surface with raw of simple setae. Appendix masculine extending slightly beyond endopod apex.

Description of male. Body about 2.3 times as long as greatest width. Head and pereonites 1–4 dorsal surfaces smooth; pereonite 5 with 2 transverse rows of weak tubercles; pereonites 6–7 with 2 rows of small tubercles. Pleon: with a transverse row of tubercles over two sutures at either side, dorsally bearing scattered uneven tubercles of various sizes, posterior margin with two triangular extensions; posterolateral margins with two fringes of very long sub-marginal setae.

Pleotelson bearing scattered small tubercles over lateral surfaces, with 2 prominent longitudinal ridges, each flanked on either lateral side by 3 prominent tubercles, one posterior to the other; dorso-median surface bearing 2 longitudinal rows of small tubercles between dorsal ridges; posterior half with medial, hemispheric dome, bearing tuft of dense long setae on anterior part, apex of pleotelson with short blunt lateral lobes; medial lobe extending just beyond the level of lateral lobes ( Figs 12 View FIGURE 12 A, B; 20F, G).

Antennule ( Fig. 12 View FIGURE 12 C) first peduncle article bearing scattered weak tubercles, all apically setose, with 4 sensory palmate sub-marginal setae on ventral margin; articles 2 with 6 small sensory palmate setae on ventral margin, article 3 slender, 1.7 times as long as article 2; flagellum with 18 articles, articles 4–17 each bearing single aesthetasc.

Antenna ( Fig. 12 View FIGURE 12 D) peduncle article dorsal margin fringed with small marginal and 1 stout setae; articles 2 ventral margin fringed with small marginal and 1 stout seat; articles 3–5 each bearing long setae on posterior corner, articles 5 about 1.2 times as long as article 4; flagellum with 23 articles each bearing tuft of long setae on dorsal margin.

Epistome ( Fig. 12 View FIGURE 12 E) granulate, with acute apex.

Left mandible ( Fig. 13 View FIGURE 13 C, D) lacinia mobilis with 3 cusps; spine row of 7 serrate spines. Palp article 1 longer than 2, articles 2 and 3 distolateral margins with approximately 11 and 22 biserrate setae.

Right mandible ( Fig. 1 View FIGURE 1 C, D; 13E) lacinia mobilis absent or modified to distally trifurcate spine joined to spine row of 6 serrate spines.

Maxillule ( Fig. 13 View FIGURE 13 A) lateral endite with long fine setae on mesial margin, outer margin bearing smaller setae, apical margin with 10 simple or serrate RS; mesial endite with 4 long, robust, comb and 2 short simple setae.

Maxilla ( Fig. 13 View FIGURE 13 B) lateral and middle endites each with 9–10 curved pectinate RS; mesial endite with 2 long rarely plumose, 2 long robust comb, about 10 robust proximally plumose and distally biserrate, and some slender simple setae.

Maxilliped ( Fig. 13 View FIGURE 13 E) endite lateral margin sinuate, mesial margin with single coupling hook, distal margin with 5 blunt rarely plumose robust submarginal setae, 3–4 robust serrate and about 6 long circumplumose RS, inner surface with 3 long circumplumose RS.

Pereopod 1 ( Fig. 13 View FIGURE 13 G) basis about 2.6 times as long as greatest width anterodorsal magin fringed with fine setae; ischium superior margin with 2 RS on medial angle; merus superodistal angle with 4 robust and 1 biserrate setae, inferior margin with 6 robust biserrate setae and single long apically palmate seta; carpus inferior margin with 4 robust biserrate setae; propodus inferior margin with 5 robust biserrate setae.

Pereopod 2 ( Fig. 13 View FIGURE 13 H) ischium superior margin with 1 RS on medial angle; merus, carpus and propodus inferior margin fringed with short setae; merus inferior margin fringed with 3 robust biserrate and single long apically palmate setae; propodus inferior margin with 6 robust biserrate setae.

Pereopod 3 ( Fig. 14 View FIGURE 14 A) is similar to pereopod 2. Pereopods 4 ( Fig. 14 View FIGURE 14 B) and 5 ( Fig. 14 View FIGURE 14 C) are similar as illustrated.

Pereopod 6 ( Fig. 14 View FIGURE 14 D) basis about 3.3 times as long as greatest width, superior margin fringed with simple and 2 sensory palmate setae; ischium superior margin with 9–10 long RS; merus superior distal margin with 7 long setae, inferior margin with 9 roust biserrate setae with various sizes and 1 single long apically palmate seta; carpus subequal in length to merus, inferior margin with 11 robust biserrate setae and 1 single long apically palmate seta, distal margin with 5 robust biserrate and 2 simple setae; propodus superodistal corner with 4 slender and 1 single sensory palmate setae, inferior margin with 5 robust biserrate setae.

Pereopod 7 ( Fig. 14 View FIGURE 14 E) similar to pereopod 6 except in some details such as number of setae.

Penial processes ( Fig. 15 View FIGURE 15 F) about 10 times as long as basal width, tapering to narrowly rounded apex; bearing serrated scales and fine setae proximally, distal half covered with dense cuticular branched scales.

Pleopod 1 ( Fig. 15 View FIGURE 15 A) exopod and endopod with 48 and 26 plumose marginal setae; endopod nearly triangular, medial margin bearing a longitudinal fold fringed with fine setae; sympod mesial margin with 4 coupling hooks.

Pleopod 2 ( Fig. 15 View FIGURE 15 B) exopod and endopod with 44 and 22 plumose marginal setae; appendix masculina arising sub-basally, extending slightly beyond endopod (by about 0.1 its length), distal part folded with narrowly rounded apex, proximally with marginal fine setae, distal part covered with cuticular scales; sympod with 3 distomesial coupling hooks, lateral margin with a long robust plumose seta.

Pleopod 3 ( Fig. 15 View FIGURE 15 C) exopod and endopod with 48 and 20 plumose marginal setae; sympod with 3 distomesial coupling hooks.

Pleopod 4 ( Fig. 15 View FIGURE 15 D) exopod lateral margin with 34 slender simple setae set between fine marginal setae (10 distally of and 24 under the transverse suture).

Pleopod 5 ( Fig. 15 View FIGURE 15 E) exopod lateral margin with 26 slender simple marginal setae (3 distally of and 23 under the transverse suture), medial margin with a single marginal seta; endopod lateral margin fringed with fine setae on about one-fourth of distal length.

Uropodal rami ( Fig. 12 View FIGURE 12 A, 21B) subequal, extending beyond pleotelsonic medial lobe apex; endopod bearing scattered small tubercles over surface, all apically setose, distally oblique; exopod wider than endopod, distally with conical acute tip; lateral margin stout, setose and tuberculate; medial margin rounded fringed with dense setae, dorsomedial surface with a row of simple setae.

Female. Pleotelsonic medial lobe round, extending just beyond lateral lobes; lateral lobes narrowly rounded; uropod rami short and not reaching to the pleotelson apex ( Fig. 12 View FIGURE 12 F).

Remarks. Cymodoce richardsoniae was originally described by Nobili (1906) from the Red Sea. Torelli (1930), Omer-Cooper and Rawson (1934) and Glynn (1972) considered that C. richardsoniae was a junior synonym of C. truncata Leach, 1814 . However, we agree with Monod (1937) and Harrison and Holdich (1984) that C. richardsoniae is a distinct species, confirmed by the redescription given here.

The taxonomy of species within Cymodoce is complex, and there are morphologically similar species. Species described in the nineteenth century were very briefly described, the descriptions consisting primarily of family and generic level characters, and therefore it is not always possible to confirm identity against these descriptions. In the original brief description of C. richardsoniae important diagnostic characters were not mentioned or figured (ICZN Art. 75.3.1). No type material of the marine isopods described by Nobili (1905, 1906a, 1906b, 1907) has ever been located, despite repeated attempts by the second author. It can reasonably accepted that the type material for C. richardsoniae is no longer extant (ICZN Art. 75.3.4), and a neotype is therefore needed to stabilize the nomenclature. The neotype selected is consistent with the original figures and description (Art. 75.3.5). As stated above, the origin of the type specimen was the Red Sea and the neotype selected also comes from area (Art. 75.3.6). The present material has been compared to the description and illustration given by Nobili (1906), and to fresh material from the Red Sea, the stated type locality.