Cnemidocarpa hemprichi Hartmeyer, 1916

Mondal, Jhimli & Raghunathan, C., 2022, Addition of three Ascidian species to Indian waters from Andaman and Nicobar Islands, Records of the Zoological Survey of India 122 (3), pp. 275-282 : 278

2. Cnemidocarpa hemprichi Hartmeyer, 1916

Material examined: 2 ex.: India, Andaman and Nicobar Islands, District North and Middle Andaman, Trilby Island , 13°24.577’N, 93°04.226’E, Depth : 7 m, 18. viii.2014, Coll.: Jhimli Mondal (Reg. No.: ZSI/ANRC-16553) .

Description: The specimen is 1.2 cm long and 1.5 cm in width, oval and attached by the left side of the body ( Figure 3a ). The test is thick, cartilaginous and sands thinly cover the surface of the test. Siphons are wart-like structures with four lobes on each of them. Anteriorly the specimen has a salmon pink colour ( Figure 3a ). Colour persists in preservatives.

The body wall is thin with muscles radiating from each siphon. Both siphons have circular and longitudinal muscles. 21 branchial tentacles are arranged in two-sized order along with 3-4-minute tentacles surrounding the branchial aperture ( Figure 3b&c ). The prepharyngeal area is narrow, forming v-shaped bending at the position of the dorsal tubercle. The U-shaped opening is found on the dorsal tubercle ( Figure 3d ). The dorsal lamina is smooth. On each side of the body, four branchial folds are present ( Figure 3b ). About 10 stigmata are present per mesh. Parastigmatic vessels are also present.

Branchial formula: DL 0 (11) 3 (11) 3 (12) 3 (9) 3 E (left side).

Gut forms a loop ( Figure 3e ). The stomach is with 26 longitudinal folds internally ( Figure 3f ). The anal border is smooth. The gut loop encloses small endocarps. Endocarp is also present on the body wall, scattered on both sides of the body. Gonads are long, five are present on the left side and eight are on the right side of the body ( Figure 3b & e ).

Remarks: In the present species, five gonads are present on the left side and eight are present on the right side of the body. While the species of Monniot C. (2002) consist of smaller number of gonads on both sides, which also matches with the Cnemidocarpa madagascarensis Hartmeyer, 1916 . C. madagascarensis is synonymous with Cnemidocarpa hemprichi . However, the original description of C. hemprichi Hartmeyer, 1916 supports the presence of more numbers of gonads on both sides of the body. With the description of the species, he illustrates six gonads on the left and nine on the right ( Hartmeyer, 1916). Millar (1985) reported Cnemidocarpa madagascariensis Hartmeyer var. regalis Michelsen, 1922 (which is also synonymous with the present species) with five gonads on the left and nine gonads on the right. Hence, the present species is identified as C. hemprichii .

Distribution: India: Andaman and Nicobar Islands ( Figure. 1 ); Elsewhere: Red Sea ( Hartmeyer, 1916), Madagascar, New Zealand ( Millar, 1985), Mauritius and Yemen ( Monniot, 2002).

Figures

Figure 1. Study areas of Andaman and Nicobar Islands.

Figure 3. Cnemidocarpa hemprichi Hartmeyer, 1916: a. Preserved specimen. b. Branchial sac with folds. c. branchial tentacles. d. Dorsal tubercle. e. Gut loop on the left side of the body along with gonad. f. Stomach. (Abbreviation: DL: Dorsal Lamina, DT: Dorsal Tubercle, E: Endostyle, EC: Endocarp, G: Gonad, S: Stomach, each number denoting each branchial fold), (Scale: b– 2mm, 9.08x; c– 1mm; d– 500μm, 42.7x; e– 2mm, 13.5x; f– 1mm, 27.2x).