Cistopus chinensis, Zheng & Lin & Lu & Ma, 2012

Zheng, Xiaodong, Lin, Xiangzhi, Lu, Chungcheng & Ma, Ruijuan, 2012, A new species of Cistopus Gray, 1849 (Cephalopoda: Octopodidae) from the East and South China Seas and phylogenetic analysis based on the mitochondrial COI gene, Journal of Natural History 46 (5 - 6), pp. 355-368 : 358-366

publication ID	https://doi.org/ 10.1080/00222933.2011.639964
DOI	https://doi.org/10.5281/zenodo.10536895
persistent identifier	https://treatment.plazi.org/id/703D87A0-FFC2-FA55-BEA3-FB9FF174FC12
treatment provided by	Felipe
scientific name	Cistopus chinensis
status	sp. nov.

Treatment

Cistopus chinensis View in CoL sp. nov.

(Figures 15)

Type material

Holotype. CMRC-XKS-0908026, Xiamen, 24 ◦ 31 ′ N, 118 ◦ 03 ′ E, mudflat, 14 August 2009, mature male, 51.3 mm DML, coll. CMRC ( Figure 1 View Figure 1 ). GoogleMaps

Paratypes. Seven paratypes, CMRC-XKS-0906025, Xiamen, 24 ◦ 31 ′ N, 118 ◦ 03 ′ E, mudflat, 14 August 2009, submature female, 39.3 mm DML GoogleMaps , coll. CMRC. OUC- XKS001, Xiamen, 24 ◦ 28 ′ N, 118 ◦ 02 ′ E, mudflat, 2 August 2009, mature female, 56.0 mm DML GoogleMaps , coll. GBSS. OUC-XKS002, Xiamen, 24 ◦ 28 ′ N, 118 ◦ 02 ′ E, mudflat, 2 August 2009, mature male, 81.0 mm DML GoogleMaps , coll. GBSS. OUC-XKS003, Xiamen, 24 ◦ 28 ′ N, 118 ◦ 02 ′ E, mudflat, 2 August 2009, mature female, 99.5 mm DML GoogleMaps , coll. GBSS. OUC-XKS008, Xiamen, 24 ◦ 28 ′ N, 118 ◦ 02 ′ E, mudflat, 2 August 2009, mature male, 65.0 mm DML GoogleMaps , coll. GBSS. OUC-XKS009, Xiamen, 24 ◦ 28 ′ N, 118 ◦ 02 ′ E, mudflat, 2 August 2009, mature male, 77.8 mm DML GoogleMaps , coll. GBSS. OUC-XKS010, Xiamen, 24 ◦ 28 ′ N, 118 ◦ 02 ′ E, mudflat, 2 August 2009, mature female, 75.4 mm DML GoogleMaps , coll. GBSS.

Other material. OUC-XKS011, mature male, 66.5 mm DML, coll. GBSS. OUC- XKS012, mature female, 59.8 mm DML, coll. GBSS. OUC-XKS013, mature male, 75.6 mm DML, coll. GBSS. OUC-XKS014, mature female, 63.2 mm DML, coll. GBSS. OUC-XKS015, mature female, 59.2 mm DML, coll. GBSS. OUC-XKS016, mature female, 56.3 mm DML, coll. GBSS. OUC-XKS017, mature male, 50.6 mm DML, coll. GBSS. OUC-XKS018, mature female, 50.6 mm DML, coll. GBSS. The eight specimens from OUC-XKS011 to OUC-XKS018 were all obtained in Xiamen, 24 ◦ 28 ′ N, 118 ◦ 02 ′ E, mudflat, 2 August 2009. OUC-XKS-WH001, Wuchuan, 21 ◦ 23 ′ N, 110 ◦ 47 ′ E, mudflat, 19 April 2011, male (mature), 71.8 mm DML GoogleMaps , coll. GBSS. OUC- XKS-WH002, Wuchuan, 21 ◦ 23 ′ N, 110 ◦ 47 ′ E, mudflat, 19 April 2011, male (mature), 83.0 mm DML GoogleMaps , coll. GBSS. OUC-XKS-WH003, Wuchuan, 21 ◦ 23 ′ N, 110 ◦ 47 ′ E, mudflat, 19 April 2011, female (mature), 92.0 mm DML GoogleMaps , coll. GBSS.

Etymology

The specific epithet chinensis refers to China as the only known locality for this species to date.

Diagnosis

Small to moderate-sized species, DML to around 99.5 mm, weight to 94.6 g. Arms approximately two to four times DML. Hectocotylized arm with ligula (about 2.4% of arm length) and distinct calamus. Gills with 9–11 lamellae per demibranch. Sucker counts 81–126 on normal arms, 57–67 on hectocotylized arm of males. Mature males with one or two enlarged suckers (10th to 11th) on arms 1, 2 and 4. Mature females with 60–130 large eggs (11–15 mm, approximately 10–25% of DML). Colour grey in fresh specimens. Skin with white low papillae on dorsal mantle.

Description

The following description is based on nine mature males and ten females (nine mature and one submature) from Xiamen, Fujian Province in 2009 and Wuchuan, Guangdong Province in 2011. Counts and measurements for some of these specimens are presented in Table 2 .

Small to moderate-sized species, TL to approximately 445.5 mm, DML to approximately 99.5 mm, weight to 94.6 g in material examined. Mantle elongate, separated from head by a narrow neck region ( Figure 1 View Figure 1 ). Head narrow (24.2–39.7% of DML; 53.6–63.1% of MW). Eye small (7.8–9.9% of DML). Funnel of moderate length (28.4–31.3% of DML). Funnel organ W-shaped, length of outer limbs 71.4–76.9% of medial limbs, slightly thinner than medial limbs ( Figure 2A View Figure 2 ). Arms moderately long and stout, two to four times length of DML. Arm formula typically 1>2>3>4. Web shallow, depth 2.2–12.9% of longest arm, web formula typically A>B>C>D>E, but varied. Suckers in two rows, medium-sized in females (to 10.8% of DML). Mature males with one or two enlarged suckers (10th to 11th on arms 1, 2 and 4, no enlarged sucker on arm 3 of mature male ( Figure 3B View Figure 3 ). Enlarged sucker diameter index (SDeI) 8.1–15.3%, largest normal sucker diameter index (SDnI) 4.2–11.3%. Within an individual specimen, the diameter of enlarged suckers is 1.3–2 times that of adjacent normal suckers. Third right arm of mature males hectocotylized. Sucker count 81–126 on normal arms, 57–67 on hectocotylized arms of males. Hectocotylized arm with ligula and calamus ( Figures 2C View Figure 2 , 3A View Figure 3 ). Ligula spoon-shaped, length about 2.4% of hectocotylized arm, with transverse ridges and grooves on oral surface. Spermatophore groove conspicuous by its white colour in contrast to the grey-coloured and spotted arm. Calamus distinct, length about one-third to one-half of ligula. Stylet: thin, clear, nonmineralized rod ( Figure 2D View Figure 2 ), length about 28% of DML. Gills with 9 to 11 lamellae per demibranch.

Digestive tract illustrated in Figure 2E View Figure 2 . Anterior salivary glands moderate, approximately one-third length of buccal mass. Posterior salivary glands well developed, slightly larger than buccal mass. Crop with distinct diverticulum. Caecum with approximately one whorl. Intestine long. Digestive gland well developed, with yellowish brown colour. Ink sac small. Anal flaps present.

Chitinous beaks dark brown. Upper beak ( Figure 4A View Figure 4 ) with a short hooked rostrum, narrow hood, short, triangular wings and lateral wall. Lower beak with a short rostrum, narrow hood, long and moderately broad wings ( Figure 4B,C View Figure 4 ). Radulae ( Figures 2B View Figure 2 , 4D,E View Figure 4 ) with seven transverse rows of teeth and two rows of marginal plates. Rhachidian tooth big, leaf-shaped, with one or two sharp lateral cusps on each side of median cone. Lateral cusps in asymmetrical seriation, migrating from lateral to medial position over two rows. First lateral tooth smallest, with one medial cusp, second lateral tooth with wide heel, one dagger-like cusp, base concave, third lateral tooth with a long sabre-like cusp, short base.

Male reproductive tract illustrated in Figure 5 View Figure 5 (A). Terminal organ muscular hollow tube, length variable (12.5–19.6% DML) in mature males, curved with small diverticulum. Vas deferens duct relatively long and coiled. Spermatophore storage sac of mature male full of mature spermatophores. Spermatophores ( Figure 5C View Figure 5 ): average length 40 mm (35–45 mm), approximately 45% of mantle length, narrow (width 0.5–0.7 mm); approximately 10–50 spermatophores in storage sac. Ejaculatory apparatus coiled for approximately one-third of spermatophore length. Sperm reservoir roughly 50% of total spermatophore length.

Female reproductive tract illustrated in Figure 5 View Figure 5 (B). Distal oviducts long and thin. oviducal glands without radiating chambers, wrapped in ligament. Mature females with about 120–135 ovarian eggs, clavate or cone-shaped. About 60–130 large eggs were laid ( Figure 5D View Figure 5 ), EgL about 11–15 mm (average 12.4 mm), EgW about 2.5–3 mm (average 2.9 mm) ( Figure 5E View Figure 5 ).

Mucous pouches present on oral surface of webs close to mouth and located between each of the arm bases, with a pore on each pouch, pores located at level of second or third proximal sucker, interbrachial membranes without other anomaly. Mucous pouches sexually dimorphic: length of pouches 3.8–8.3 mm in males, 3.2–5.0 mm in females, pores sometimes difficult to recognize in females ( Figure 3C,D View Figure 3 ).

Colour of live specimens light brown, with some tiny white papillae on dorsal mantle ( Figure 3E View Figure 3 ). Significant gold-coloured stripes present between eyes. Base of arms and web near buccal membrane white.

Distribution

East China Sea and South China Sea, mainly coastal waters of Zhejiang and Fujian Provinces, in muddy bottom. They were also found in Guangdong and Guangxi Provinces .

Molecular analysis

Fragments 658 base pairs in length were obtained from the mitochondrial COI gene of six specimens collected in Xiamen in June 2009. Estimated base frequencies were A = 0.3050, C = 0.1991, G = 0.1418 and T = 0.3541. A + T content was 65.91%. No gaps were found in any of the sequences analyzed. There were two different haplotypes, which have a single nucleotide transition at Site 305(A→G) .

The genetic distance ranged from 0.000 to 0.002 among the six individuals of C. chinensis sp. nov. The closest taxon with respect to genetic distance was C. indicus (0.118 –0.121), and the most distant in the genus was C. taiwanicus (0.124 –0.126). Cistopus chinensis sp. nov. could be clearly separated from other species of the genus using a distance method based on the Kimura two-parameter model.

In the mitochondrial DNA-based tree, maximum likelihood, neighbour-joining and maximum parsimony analyses were conducted. The topology of phylogenetic trees was similar in all analyses and supported by bootstraps based on 1000 replicates. A monophyletic cluster (bootstrap 100%/92%/99%) included the six specimens of C. chinensis sp. nov. ( Figure 6 View Figure 6 ). The monophyly of the Cistopus (bootstrap 91%/89%/83% in Figure 6 View Figure 6 ) was well supported, but polyphyly was indicated in the genus Octopus .