Tetraclita rufotincta Pilsbry, 1916

Chan, Benny Kwok Kan, Hsu, Chih-Hsiung & Tsai, Pei-Chen, 2009, Morphology and distribution of the acorn barnacle Tetraclita reni nom. nov. (Crustacea: Cirripedia) in Madagascar and adjacent waters, Zootaxa 2019, pp. 57-68 : 64

publication ID	https://doi.org/ 10.5281/zenodo.186037
DOI	https://doi.org/10.5281/zenodo.6224768
persistent identifier	https://treatment.plazi.org/id/796FEF4F-0A7C-A058-04B5-4CCC72A1C85E
treatment provided by	Plazi
scientific name	Tetraclita rufotincta Pilsbry, 1916
status

Treatment

Figures 2 View FIGURE 2 B, 2C, 3D–F, 6, 7

Tetraclita squamosa rufotincta Pilsbry, 1916: 253 –254, pl. 58, figs. 5–6a (Gulf of Aden-type locality). Tetraclita porosa rufotincta— Nilsson-Cantell, 1928:35, fig. 16 ( Muscat, Gulf of Oman). Tetraclita squamosa rufotincta— Utinomi, 1969: 92 (Nabiyu Tunb, Strait of Hormuz). Tetraclita rufotincta . - Ross, 1999

(Red Sea).

Material examined. South Yemen, MNHN, Paris, Tetraclita rufotincta (3 specimens), det Diana Jones; Islet east of Shimoni, Kenya, NHM, London, Tl978. 370-379, Tetraclita rufotincta (2 specimens), 20-November- 1971, coll, J.D. Taylor, det A.J. Southward; Aldabra, Indian Ocean, NHM, London, 1978.47, Tetraclita sp. (3 specimens), Dune Jean Louis, 16-August-1973, coll. J.D. Taylor; Lontide Muscat (Gulf of Oman), NHM, London, 1902.12.8.3–8, Tetraclita porosa var rufotincta (4 specimens); Kosi Bay, Mozambique, NHM, London, 1967. 3 .14.31, Tetraclita rufotincta (1 specimen), coll. 13.7.49, University of Cape Town, Ecological Survey; Madagascar (Nossy-Kousba), MNHN, Paris, Tetraclita squamosa rufotincta (1 specimen), 1991, coll. Joly; Tanikely, Madagascar, MNHN, Paris, CI674, CI675, Tetraclita rufotincta (3 specimens), 1- April-1960.

Description. Parietes pink, surfaces of some older specimens with white patches due to erosion. Posterior side of scutum and tergum varying from pink to white. Tergum spur sharp ( Fig. 2 View FIGURE 2 B); mean basi-scutal angle 110 ± 13° (n = 6, pooled specimens from Aldabra, Kenya and South Yemen); lateral depressor muscle crests 7–10. Scutum triangular, large teeth on occludent margin ( Fig. 2 View FIGURE 2 B); adductor muscle scar deep; depressor muscle crests 10–11. Cirrus I with rami unequal, exopodite (20 segments, Yemen sample) longer than endopodite (12 segments, Yemen sample; Fig. 3 View FIGURE 3 D); rami ( Fig. 6 View FIGURE 6 A) bearing serrulate setae with 3 rows of setules ( Fig. 6 View FIGURE 6 D), feathery serrulate setae ( Fig. 6 View FIGURE 6 E) and blade-shaped serrulate setae with very short and sparse setules ( Fig. 6 View FIGURE 6 J); coxa and base of protopod with feathery serrulate setae ( Fig. 6 View FIGURE 6 F). Cirrus II shorter than cirrus I; exopodite (15 segments, Yemen sample) and endopodite (13 segments, Yemen sample) similar length ( Fig. 3 View FIGURE 3 E, 6B). Setal types of cirrus II similar to cirrus I ( Fig. 6 View FIGURE 6 A, B), except blade-shaped setae with short, sparse setules absent ( Fig. 6 View FIGURE 6 J); coxa with plumose setae ( Fig. 6 View FIGURE 6 G). Cirrus III with exopodite (11 segments, Yemen sample) and endopodite (11 segments, Yemen sample) similar length ( Fig. 3 View FIGURE 3 F, 6C); cirrus III exhibiting highest diversity of setal types ( Fig. 6 View FIGURE 6 C); setae on base and coxa of protopod plumose ( Fig. 6 View FIGURE 6 G) and serrulate ( Fig. 6 View FIGURE 6 F); rami with serrulate setae ( Fig. 6 View FIGURE 6 D, E, H), bidentata, serrate setae ( Fig. 2 View FIGURE 2 C, Fig. 6 View FIGURE 6 I) and thick, bladeshaped, serrulate setae with short setules ( Fig. 6 View FIGURE 6 J). Rami of cirri IV, V, VI with serrulate setae, each with 1 row of setules ( Fig. 6 View FIGURE 6 K, L); segmental junctions with short, simple setae ( Fig. 6 View FIGURE 6 M).

Labrum concave, 4–5 large teeth on each side of notch ( Fig. 7 View FIGURE 7 A, B); posterior side of labrum with serrulate setae ( Fig. 7 View FIGURE 7 C). Mandible with 4 teeth, 2nd and 3rd bidentate, 4th tridentate ( Fig. 7 View FIGURE 7 D, E, F); lower angle with 5–6 small setae ( Fig. 7 View FIGURE 7 E). Maxillule notched, 2 large setae at upper notch, 8 setae on lower notch ( Fig. 7 View FIGURE 7 I, J). Mandibulatory palp oval ( Fig. 7 View FIGURE 7 G, H). Maxilla bilobed with long setae, notch between lobes non-setose ( Fig. 7 View FIGURE 7 K, L). Maxillule, mandibulatory palp and maxilla with serrulate setae( Fig. 7 View FIGURE 7 J, K, L).

Diagnosis. Tetraclita rufotincta can be distinguished from T. reni nom. nov. by the lack of

multicuspidate setae on cirrus III, and the tergum with a sharper spur and a smaller basi-scutal angle when compared to T. reni nom. nov.

Distribution. West coast of India ( Mumbai), Gulf of Aden, Red Sea, East coast of Africa, NW Madagascar.

Remarks. Tetraclita rufotincta is a widely distributed species in the West Indian Ocean. Pilsbry (1916) identified this species from Aden (type locality) and concluded specimens from Zanzibar, East Africa, were also T. rufotincta . Pilsbry (1916), however, noted there were intra-specific morphological variations between a Zanzibar specimen and the Aden specimens. The Zanzibar specimen had a tergum with a spur which was 'less deeply entered' (i.e. larger basi-scutal angle) and a straighter scutal margin, and a scutum with deeper articular furrows when compared to the Aden specimens. In the present study, Tetraclita rufotincta specimens from Aldabra appeared to have a larger basi-scutal angle (spur less deeply entered) than those from Kenya and Aden ( Fig. 2 View FIGURE 2 B). The setal types of cirri and mouth parts of these populations were similar. As there are no obvious diagnostic morphological variations between these populations, they are considered as T. rufotincta in the present study. However, since there are intra-specific morphological variations among geographical populations, it is likely that T. rufotincta contains a cryptic species complex in the West Indian Ocean. Further studies should be conducted on molecular analysis to compare the genetic differentiation of T. rufotincta in different geographical populations of the West Indian Ocean to further ascertain the taxonomic status of the barnacle from different geographical locations.