Tetraclita rufotincta Pilsbry 1916
Creators: name: Chan, Benny Kwok Kan
name: Hsu, Chih-Hsiung
name: Tsai, Pei-Chen
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Maxillopoda
Sessilia
Tetraclitidae
Tetraclita
Tetraclita rufotincta

description: Tetraclita rufotincta Pilsbry, 1916
Figures 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 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 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 D); rami (Fig. 6 A) bearing serrulate setae with 3 rows of setules (Fig. 6 D), feathery serrulate setae (Fig. 6 E) and blade-shaped serrulate setae with very short and sparse setules (Fig. 6 J); coxa and base of protopod with feathery serrulate setae (Fig. 6 F). Cirrus II shorter than cirrus I; exopodite (15 segments, Yemen sample) and endopodite (13 segments, Yemen sample) similar length (Fig. 3 E, 6B). Setal types of cirrus II similar to cirrus I (Fig. 6 A, B), except blade-shaped setae with short, sparse setules absent (Fig. 6 J); coxa with plumose setae (Fig. 6 G). Cirrus III with exopodite (11 segments, Yemen sample) and endopodite (11 segments, Yemen sample) similar length (Fig. 3 F, 6C); cirrus III exhibiting highest diversity of setal types (Fig. 6 C); setae on base and coxa of protopod plumose (Fig. 6 G) and serrulate (Fig. 6 F); rami with serrulate setae (Fig. 6 D, E, H), bidentata, serrate setae (Fig. 2 C, Fig. 6 I) and thick, bladeshaped, serrulate setae with short setules (Fig. 6 J). Rami of cirri IV, V, VI with serrulate setae, each with 1 row of setules (Fig. 6 K, L); segmental junctions with short, simple setae (Fig. 6 M).
Labrum concave, 4–5 large teeth on each side of notch (Fig. 7 A, B); posterior side of labrum with serrulate setae (Fig. 7 C). Mandible with 4 teeth, 2nd and 3rd bidentate, 4th tridentate (Fig. 7 D, E, F); lower angle with 5–6 small setae (Fig. 7 E). Maxillule notched, 2 large setae at upper notch, 8 setae on lower notch (Fig. 7 I, J). Mandibulatory palp oval (Fig. 7 G, H). Maxilla bilobed with long setae, notch between lobes non-setose (Fig. 7 K, L). Maxillule, mandibulatory palp and maxilla with serrulate setae(Fig. 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 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.
description: Published as part of 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, pp. 57-68 in Zootaxa 2019 on page 64, DOI: 10.5281/zenodo.186037