Research Article |
Corresponding author: Luiz A. Rocha ( lrocha@calacademy.org ) Academic editor: Maria Elina Bichuette
© 2019 Yi-Kai Tea, Hudson T. Pinheiro, Bart Shepherd, Luiz A. Rocha.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Tea Y-K, Pinheiro HT, Shepherd B, Rocha LA (2019) Cirrhilabrus wakanda, a new species of fairy wrasse from mesophotic ecosystems of Zanzibar, Tanzania, Africa (Teleostei, Labridae). ZooKeys 863: 85-96. https://doi.org/10.3897/zookeys.863.35580
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Cirrhilabrus wakanda sp. nov. is described on the basis of the holotype and four paratypes collected between 50 and 80m depth over low-complexity reef and rubble bottoms at the east coast of Zanzibar, Tanzania, Africa. The new species belongs to a group of fairy wrasses from the western Indian Ocean, sharing a combination of characters that include: short pelvic fins (not or barely reaching anal-fin origin); relatively unmarked dorsal and anal fins; males with a strongly lanceolate caudal fin (except in C. rubrisquamis); both sexes with a pair of prominent facial stripes above and below the orbit; and both sexes with prominent purple scales and osseus elements that persist, and stain purple, respectively, even in preservation. This group of fairy wrasse is part of a larger complex that includes related species from the western Pacific Ocean. In addition to meristic and morphometric comparisons, we also compare mitochondrial DNA sequence data to the aforementioned, putatively related species.
Coral reefs, deep reefs, Indian Ocean, rebreather diving, reef fish
The labrid fish genus Cirrhilabrus Temminck & Schlegel, 1845 consists of small, colourful, planktivorous fishes found mostly on rubble slopes adjacent to coral reefs.
Members of this genus occur exclusively within the Indo-Pacific, attaining their highest diversity in the western Pacific Ocean and eastern Indian Ocean. In contrast, only seven nominal species have been reported from the western Indian Ocean, just slightly more than 10% of the genus. These are: Cirrhilabrus exquisitus Smith, 1957, C. blatteus Springer & Randall, 1974, C. rubriventralis Springer & Randall, 1974, C. rubrisquamis Randall & Emery, 1983, C. sanguineus Cornic, 1987, C. africanus Victor, 2016, and C. rubeus Victor, 2016. Of these, C. sanguineus, C. blatteus, and C. rubrisquamis are common only in mesophotic ecosystems, at depths greater than 40 m (
Mesophotic coral ecosystems (MCEs) characterise the deeper portions of coral reefs, found between 30 and 150 m (
Specimens of the new species were collected using hand nets while diving on mixed-gas, closed-circuit rebreathers (Hollis Prism 2). Methods of counting and measuring follow
Proportional measurements of type specimens of Cirrhilabrus wakanda sp. nov. expressed as a percentage of the standard length.
Holotype | Paratypes | ||||
CAS 246395 | CAS 246397 | CAS 246398 | CAS 246399 | CAS 246396 | |
Sex | male | male | female | female | female |
Standard length (mm) | 70.3 | 61.3 | 57.4 | 54.3 | 56.8 |
Body depth | 30.9 | 31.7 | 29.8 | 31.9 | 31.8 |
Body width | 11.8 | 12.9 | 12.6 | 13.9 | 14.5 |
Head length | 31.0 | 30.6 | 31.2 | 30.1 | 27.7 |
Snout length | 8.0 | 8.9 | 7.9 | 8.2 | 7.4 |
Orbit diameter | 6.6 | 8.0 | 7.2 | 9.0 | 7.7 |
Interorbital width | 8.5 | 9.6 | 7.7 | 9.3 | 9.1 |
Upper jaw length | 6.9 | 8.2 | 6.5 | 7.4 | 8.2 |
Caudal-peduncle depth | 15.1 | 16.3 | 14.8 | 16.3 | 16.5 |
Caudal-peduncle length | 12.8 | 16.5 | 14.1 | 14.9 | 14.8 |
Predorsal length | 32.6 | 33.8 | 31.9 | 31.7 | 33.7 |
Preanal length | 60.4 | 59.5 | 59.6 | 58.5 | 61.4 |
Prepelvic length | 34.4 | 33.1 | 31.5 | 35.7 | 36.4 |
Dorsal-fin base | 58.2 | 56.6 | 55.3 | 63.2 | 57.0 |
First dorsal spine | 5.4 | 6.5 | 6.2 | 5.2 | 6.4 |
Longest dorsal spine | 11.9 | 14.3 | 12.4 | 13.6 | 12.7 |
Longest dorsal ray | 19.0 | 18.3 | 16.8 | 16.7 | 17.2 |
Anal-fin base | 26.1 | 25.3 | 25.4 | 27.6 | 24.6 |
First anal spine | 6.0 | 6.4 | 5.2 | 5.7 | 6.4 |
Second anal spine | 9.1 | 9.3 | 9.3 | 9.4 | 10.1 |
Third anal spine | 10.5 | 11.1 | 10.8 | 10.9 | 11.4 |
Longest anal ray | 16.8 | 17.8 | 14.5 | 15.1 | 17.9 |
Caudal-fin length | 28.2 | 28.6 | 25.4 | 28.0 | 31.6 |
Pectoral-fin length | 19.6 | 21.8 | 20.6 | 18.3 | 20.3 |
Pelvic spine length | 11.2 | 12.1 | 11.7 | 11.0 | 11.3 |
Pelvic fin length | 18.0 | 17.9 | 16.2 | 15.5 | 18.8 |
DNA extraction and PCR amplification of the mitochondrial cytochrome c oxidase subunit I (COI) were performed following protocols detailed in
CAS 246395 (field code: HTP 900), 70.3 mm SL male, GenBank MN010585, east coast of Zanzibar, Tanzania, Africa (GPS coordinates: 6°10'30"S; 39°32'28"E), 75 m, collected by H.T. Pinheiro, B. Shepherd, and L.A. Rocha, 14 December 2018; Figure
CAS 246396 (HTP 883), 56.8 mm SL female, GenBank MN010586, east coast of Zanzibar, Tanzania, Africa, 70 m, 07 December 2018; CAS 246397 (HTP 901), 61.3 mm SL male, GenBank MN010587, east coast of Zanzibar, Tanzania, Africa, 75 m, 14 December 2018; Figure
Paratypes of Cirrhilabrus wakanda sp. nov., not to scale A1 CAS 246397, 61.3 mm SL, male, freshly euthanized A2 CAS 246397, male in preservation B1 CAS 246398, 57.38 mm SL, female, freshly euthanized B2 CAS 246398, female in preservation C1 CAS 246399, 54.32 mm SL, female, freshly euthanized C2 CAS 246399, female in preservation. Photographs by H.T. Pinheiro and B. Shepherd (A1, B1, C1), and J. Fong (A2, B2, C2).
Cirrhilabrus wakanda shares similar meristic characters to other members of this genus. However, it is readily distinguished from all other Cirrhilabrus in having the following combination of colouration and morphological characters: caudal fin strongly lanceolate in males; both sexes with a series of purple scales (in life and in preservation) arranged in a chain-link pattern across dorsal two-thirds of body.
Dorsal-fin rays XI,9; anal-fin rays III,9; dorsal and anal-fin soft rays branched except first ray unbranched in two individuals; last dorsal and anal-fin ray branched to base; pectoral-fin rays 14–15 (15/15), upper two unbranched; pelvic-fin rays I,5; principal caudal-fin rays 7+6, uppermost and lowermost unbranched; upper procurrent caudal-fin rays 6, lower procurrent caudal-fin rays 6; lateral line interrupted, with dorsoanterior series of pored scales 16–19 (17/17) and midlateral posterior peduncular series 8–9 (9/9); scales above lateral line to origin of dorsal fin 2; scales below lateral line to origin of anal fin 6; median predorsal scales 4–5 (4); median prepelvic scales 5; rows of scales on cheek 2; circumpeduncular scales 15–16 (15); gill rakers 8–9 (8) + 8–9 (8) = 16–18 (16); pseudobranchial filaments 8–10; vertebrae 9+16; epineurals 13 (Figure
Body moderately elongate and compressed, depth 3.1–3.4 (3.2) in SL, width 2.1–2.6 (2.6) in depth; head length 3.2–3.6 (3.2) in SL; snout pointed, its length 3.4–3.9 (3.9) in HL; orbit diameter 3.6–4.7 (4.7) in HL; depth of caudal peduncle 1.7–2.1 (2.1) in HL. Mouth small, terminal, and oblique, with maxilla almost reaching vertical at front edge of orbit; dentition typical of genus with three pairs of canine teeth present anteriorly at side of upper jaw, first forward-projecting, next two strongly recurved and outcurved, third longest; an irregular row of very small conical teeth medial to upper canines; lower jaw with a single stout pair of canines anteriorly which protrude obliquely outward and are slightly lateral to medial pair of upper jaw; no teeth on roof of mouth.
Posterior margin of preoperculum with 30–32 (32) very fine serrated; margins of posterior and ventral edges of preoperculum free to about level of middle pupil. Anterior nostril in short membranous tube, located nearer to orbit than snout tip; posterior nostril larger, roughly ovoid to rectangular, located just medial and anterior to upper edge of eye. Scales cycloid; head scaled except snout and interorbital space; four large scales on opercle; a broad naked zone on membranous edge of preopercle; a row of large, elongate, pointed scales along base of dorsal fin, one per element, scales progressively shorter posteriorly on soft portion of fin; anal fin with a similar basal row of scales; last pored scale of lateral line (posterior to hypural plate) enlarged and pointed; one scale above and below last pored scale also enlarged; a horizontal series of greatly enlarged scales extend two-thirds distance to central posterior margin of caudal fin; pectoral fins naked except for a few small scales at extreme base; a single large scale at base of each pelvic fin, about three-fourths length of pelvic spine.
Origin of dorsal fin above third lateral-line scale, predorsal length 3.0–3.2 (3.1) in SL; first 1–4 dorsal-fin spines progressively longer, fifth to sixth subequal, eighth to tenth longest, 2.1–2.6 (2.6) in HL; interspinous membranes of dorsal fin in males extend beyond dorsal-fin spines, with each membrane extending in a pointed filament beyond spine; fifth dorsal-fin soft ray longest, 1.6–1.9 (1.6) in HL, remaining rays progressively shorter; origin of anal fin below base of ninth dorsal-fin spine; third anal-fin spine longest, 2.4–3.0 (3.0) in HL; interspinous membranes of anal fin extended as on dorsal fin; anal-fin soft rays relatively uniform in length, sixth longest, 1.5–2.1 (1.8) in HL; dorsal and anal-fin rays barely reaching caudal-fin base; caudal fin of males lanceolate; pectoral fins short, reaching vertical between bases of fifth or sixth dorsal-fin spines, longest ray 1.4–1.6 (1.6) in HL; origin of pelvic fins below lower base of pectoral fins; pelvic fins short, not reaching past anal fin origin, longest ray 1.5–1.9 (1.7) in HL.
Based on colour photographs and specimens when freshly dead, and field photos of live individuals (Figures
A selection of Cirrhilabrus species from the western Indian Ocean group of the Cirrhilabrus jordani complex A Cirrhilabrus wakanda sp. nov., in situ photograph from the east coast of Zanzibar, Africa B Cirrhilabrus blatteus, in situ photograph from the Red Sea, off the coast of Eilat; C: Cirrhilabrus sanguineus, aquarium photograph of a specimen from Mauritius D Cirrhilabrus rubrisquamis, aquarium photograph of a specimen from the Maldives. Photographs by L.A. Rocha (A); E. Brokovich (B), and Y.K. Tea (C, D).
Similar to males described above. Head and body more subdued in colouration, pinkish-purple to lilac (Figure
(Figures
A selection of Cirrhilabrus species in preservation showing the purple staining qualities. Not to scale A Cirrhilabrus wakanda sp. nov., 70.3 mm SL, male holotype, CAS 246395 B Cirrhilabrus blatteus, 65.1 mm SL, male, CAS 235080 C Cirrhilabrus earlei, 56.5 mm SL, male paratype, CAS 213114. Photographs by L.A. Rocha (A) and B.W. Frable (B, C).
The specific epithet refers to the fictional East African nation of Wakanda, home of the superhero Black Panther, as is the case for the new species, which has remained hidden from the world for a long time. To be treated as a noun in apposition. The common name refers to the fictional metal vibranium, a rare substance found on Wakanda that is woven into Black Panther’s suit. The purple chain-link scale pattern of the new species is reminiscent of this detail.
Cirrhilabrus wakanda is presently known only from the east coast of Zanzibar, Tanzania. The species inhabits deep shelves consisting of small patch reefs dominated by rhodolith and sponge beds, at depths between 50 and 80 m.
Pairwise comparison of mitochondrial sequence data suggests that Cirrhilabrus wakanda is most closely related to C. rubrisquamis Randall & Emery (1983), differing by 0.6% in mitochondrial COI (uncorrected pairwise distance). Such marginal differences in sequence data between closely related sister species is not uncommon in Cirrhilabrus, even when stark morphological differences are present (
In Cirrhilabrus wakanda the purple scale pattern presents as a scattered, chain-link motif (Figure
The four species are part of a larger complex of fairy wrasses that includes five other species from the western Pacific Ocean: Cirrhilabrus jordani, C. earlei, C. roseafascia, C. lanceolatus, and C. shutmani. Together, these nine species form the Cirrhilabrus jordani complex. Previous morphological and molecular studies have also shown support for this grouping (
Cirrhilabrus wakanda possess several osseus elements and fin rays that stain naturally purple in ethanol (Figure
Cirrhilabrus blatteus – Red Sea, off Saudi Arabia: CAS 235080, 56.2 mm SL; 63.4 mm SL; 65.1 mm SL; Cirrhilabrus earlei – Palau: CAS 213114, 56.5 mm SL.
This work was funded by the generous support of donors who endorsed the California Academy of Sciences’ Hope for Reefs Initiative. We thank M. V. Bell, A. Fusillo, J. Armstrong, and the staff of the Rising Sun Diving Centre and Breezes Beach Club for providing diving and logistic operations in the field, C. Castillo for logistical and programmatic support, and C. Rocha and G. Arango for support from the CAS genomics lab. We also thank Zanzibar’s Institute of Marine Science of the University of Dar es Salam (through Dr. Saleh Yahya) and the Secretary of the Zanzibar Research Committee for issuing scientific collecting and export permits. D. Catania provided CAS collection numbers, J. Fong provided x-radiographs and type series photos, and B.W. Frable and E. Brokovich provided photographs of additional material examined.