Leptoclinides, Berjan, 1905

Oliveira, Livia M., Carvalho, João Paulo & Rocha, Rosana M., 2019, Leptoclinides (Ascidiacea, Didemnidae) from Brazil: new records and two new species, European Journal of Taxonomy 572, pp. 1-16 : 12-14

Leptoclinides sp.

Fig. 5

Material examined

BRAZIL • several colonies; Espírito Santo, Vila Velha, Pacotes Island ; 20º21′04″ S, 40º15′12″ W; 12 m depth; 13 Feb. 2011; R.M. Rocha leg.; DZUP LEP-009 , slide DZUP DID3.81 .

Description

Colonies are globular, small (0.5–1.0 cm wide), beige and translucent when fixed in formalin. Many colonies were found adhering to a branching alga, attached to a horizontal surface of granitic outcrop on the bottom. Many colonies had only one common cloacal aperture, while most colonies had two ( Fig. 5 A–B). The tunic is smooth and soft. Spicules (30–55 µm in diameter) are low in density and uniformly distributed throughout the colony, mostly next to the surface layer. Spicules are stellate, with six to eight rays in cross-section, and rays are long and conical, with separate bases and granular patches between them ( Fig. 5C ).

Zooids (1–2 mm long) with thorax and abdomen of about the same length. The thorax has 5–6 longitudinal muscle fibers on each side. The oral siphon is short, wide and tubular, with evident circular muscle fibers. Its margin is slightly undulate, without clear lobes. The atrial siphon is downward oriented, tubular, but with a large diameter and without lobes in the aperture. Circular muscle fibers (19–20) are conspicuous. The first three rows in the pharynx have 8–10 stigmata, while the fourth has 7–9. The thoracic organ is circular, larger than the stigmata and not salient. It is at the level of the third row of stigmata in the middle of the thorax ( Fig. 5D ). In some zooids the organ is full of spicules.

The esophago-rectal peduncle is usually short and narrow, but some zooids have a long esophagus. The abdomen is vertical. The globular stomach may be slightly overlapped by the intestinal loop. There are three stoloniferous vessels of different sizes, with the largest being half the length of the abdomen. The testis has three follicles, surrounded by 4–6 counter-clockwise (few zooids with clockwise direction) turns of the sperm duct ( Fig. 5 E–F). Larvae were absent.

Remarks

This lot was different from all others from Brazil or the Atlantic Ocean. A unique feature of this species was the globular, aggregated, small colonies. Despite their color, stellate spicule shape and male reproductive system, all of which are similar to those of L. brasiliensis , this species comprises a thin encrusting colony, with larger (2 ×) spicules, and an atrial siphon with a smaller diameter. While we suspect that this may be an undescribed species, we prefer not to name it here, due to the lack of diagnostic larvae and the few colonies we examined. It is possible that all the colonies we examined are part of the same clone and arose by fission, which is suggested by its aggregation, the small colony size and the usually single common cloaca.

Distribution

Brazil (Espírito Santo).

Figures

Fig. 5. Leptoclinides sp. (DZUP LEP-009). A. Preserved colony on algae. B. Detail of preserved colonies. C. Spicules. D. Thorax. E–F. Abdomen. Scale bars: A = 1 cm; B = 0.5 cm; D–F = 0.1 mm.