Research Article |
Corresponding author: Hudson T. Pinheiro ( htpinheiro@gmail.com ) Academic editor: Devin Bloom
© 2018 Hudson T. Pinheiro, Claudia Rocha, 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:
Pinheiro HT, Rocha C, Rocha LA (2018) Tosanoides aphrodite, a new species from mesophotic coral ecosystems of St. Paul’s Rocks, Mid Atlantic Ridge (Perciformes, Serranidae, Anthiadinae). ZooKeys 786: 105-115. https://doi.org/10.3897/zookeys.786.27382
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During a recent expedition to St. Paul’s Rocks, Atlantic Ocean, a distinctive and previously unknown species of Anthiadinae was collected at a depth of 120 m. A genetic analysis indicated the undescribed species is a member of the genus Tosanoides, which was only known to occur in the Pacific Ocean. This new taxon is distinguishable from all other Tosanoides species by the following combination of characters: soft dorsal fin rays 15–16; anal fin rays 9; ventral scale rows 9–10; last dorsal spine the longest (instead first through fourth). Here Tosanoides aphrodite sp. n. is described and illustrated, only known from St. Paul’s Rocks.
Brazil, coral reefs, deep reefs, fish endemism, oceanic island, rebreather diving
The group commonly known as anthias fishes are classified within the serranid subfamily Anthiadinae Poey, 1861 (
The mesophotic coral ecosystems (MCEs;
We collected using hand nets while diving on mixed-gas, closed-circuit rebreathers (Hollis Prism 2). We performed all counts using a microscope, with exception of vertebrae and caudal rays (primary, procurrent and rudimentary), which were counted from X-rays, and morphological characters were measured to the nearest 0.01 mm following
We sequenced and analyzed the Mitochondrial Cytochrome c oxidase subunit I (COI) DNA for the new species. DNA extraction and PCR amplification of the COI were performed following
Saint Paul’s Rocks, Brazil.
Holotype. CIUFES 3444 (Field number: CR 055). 56.8 mm SL, male, Saint Paul Rocks, Brazil. 00°56'N, 029°22'W, depth 120 m, collected by LA Rocha and HT Pinheiro using hand nets, 25 June 2017 (Figure
We compared Tosanoides aphrodite to other Anthiadinae species using the keys for the Western Central Pacific Anthiadinae species in Heemstra and Randall (1999) and for the Atlantic and Eastern Pacific Anthiadinae species in
The new species differs from all other Anthiadinae by the following combination of characters: Dorsal-fin spines X; last dorsal spine the longest, 1.8–2.2 in head length; dorsal-fin rays 15–16; 7th dorsal ray the longest, 2.65–2.80 in head length; anal-fin rays 9; pored lateral-line scales 32–35; ventral scale rows 9–10; body slender and compressed, greatest depth 2.96–3.18 in SL, and the width 1.77–2.09 in depth. Our phylogenetic analysis shows the new species belongs to Tosanoides
Morphometric and meristic data for type specimens are provided in Table
Body slender, compressed, its greatest depth 3.18 (2.96–3.13) in SL, the width just posterior to gill opening, 1.89 (1.77–2.09) in depth; head length 2.79 (2.88–3.52) in SL; snout short, its length 6.08 (4.88–7.12) in head; orbit diameter 3.34 (2.48–3.32) in head; interorbital convex, the least bony width 3.94 (2.78–4.03) in head; caudal peduncle depth 3.21 (2.33–3.56) in head. Mouth large and oblique; lower jaw not projecting beyond the upper when mouth closed; maxilla 2.15 (1.96–2.16) in head, diagonal (45°), and reaching the center of pupil. One pair of nostrils in front of each eye with no membranous tube or rims. One pair of pores on top of head between eyes, slightly anterior to center of eyes. Posterior margin of eye bordered with eight to ten pores. Lateral line very high, parallel with dorsal profile, forming an angle below last few dorsal rays and extending along middle of caudal peduncle to base of caudal fin.
Teeth in upper jaw villiform, forming a band broader anteriorly with two canines on each side, one externally directed forward and other internally directed backward, an outer row of approximately 14 slender canines on each side of jaw curved forward; lower jaw with a patch of villiform teeth anteriorly; two canines on each side anteriorly curved backwards and a third canine on each side facing forward and curved internally, an outer row of approximately 15 slender canines like those of upper jaw, pointing forward; small teeth on vomer and palatines; tongue pointed, smooth. Preopercle with a round angle, upper limb serrate with approximately 25 spinules, lower limb smooth; opercle with two flat spines, upper one longest and at apex; subopercle and interopercle smooth.
Tosanoides aphrodite is sexually dichromatic. Males (Figure
Females and juveniles (Figure
Straw-colored; fins transparent; eyes black (Figure
The name “aphrodite” refers to the ancient Greek goddess of love and beauty. While we were collecting the Aphrodite anthias, a large Six-gill shark (Hexanchus griseus) came very close to both of us (HTP and LAR), but that didn’t divert our attention from the new exquisitely beautiful species, and we never even saw the shark (https://youtu.be/pSZrmoEwR0Q). The beauty of the Aphrodite anthias enchanted us during its discovery much like Aphrodite’s beauty enchanted ancient Greek gods.
Tosanoides aphrodite is only known from Saint Paul’s Rocks, off Brazil. It was found on mesophotic coral ecosystems of the island, observed between 100 and 130 m depth while rebreather diving, and a single observation at 260 m depth, taken from a submersible dive. The species inhabits small crevices of complex rocky reefs (Figure
Morphometric and meristic data for selected characters of type specimens of Tosanoides aphrodite sp. n. Values of morphometric data are presented in mm.
Morphometrics | Holotype | Paratypes | |||||
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CIUFES 3444 |
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Sex | Male | Male | Male | Female | Female | Female (juvenile) | Female (juvenile) |
Total length (TL) in mm | 78.3 | 74.1 | 86.9 | 73.4 | 63.9 | 52.5 | 46.2 |
Standard length (SL) in mm | 56.77 | 54.89 | 59.88 | 57.09 | 47.55 | 38.91 | 33.09 |
Head length | 20.32 | 18.58 | 20.79 | 19.54 | 16.53 | 12.76 | 9.39 |
Body depth | 17.83 | 18.5 | 19.13 | 18.55 | 15.23 | 13.14 | 10.67 |
Body width | 9.42 | 9.15 | 10.82 | 8.89 | 8.53 | 6.47 | 5.46 |
Snout length | 3.34 | 2.98 | 4.26 | 3.04 | 2.88 | 1.87 | 1.32 |
Predorsal length | 18.6 | 17.93 | 18.71 | 17.94 | 14.95 | 12.58 | 10.33 |
Preanal length | 34.45 | 33.69 | 36.68 | 35.07 | 28.4 | 23.4 | 21.16 |
Base of dorsal fin | 33.09 | 31.56 | 33.45 | 33.11 | 27.12 | 20.58 | 18.25 |
Base of anal fin | 13.75 | 13.85 | 14.81 | 13.28 | 13.56 | 8.57 | 6.54 |
Orbit diameter | 6.08 | 5.59 | 6.61 | 6.3 | 5.36 | 4.62 | 3.79 |
Interorbital width | 5.16 | 5.39 | 5.16 | 5.09 | 4.49 | 3.66 | 3.38 |
Caudal peduncle depth | 6.34 | 6.41 | 5.84 | 6.53 | 5.41 | 4.51 | 4.03 |
Pelvic spine | 9.08 | 8.74 | 8.45 | 10.23 | 8.29 | 6.32 | 5.33 |
Pelvic fin | 16.15 | 14.72 | 18.11 | 21.16 | 14.17 | 10.34 | 10.51 |
First dorsal spine length | 4.16 | 3.72 | 5.07 | 4.37 | 4.78 | 2.29 | 2.46 |
Second dorsal spine length | 5.33 | 4.59 | 5.97 | 4.92 | 5.96 | 3.41 | 2.98 |
Third dorsal spine length | 7.21 | 6.21 | 8.1 | 6.28 | 6.92 | 4.25 | 4 |
Fourth dorsal Spine length | 9.34 | 7.82 | 9.35 | 8.25 | 7.8 | 5.31 | 4.65 |
Fifth dorsal spine length | 9.98 | broken | 10.89 | 8.55 | 7.92 | 5.62 | 4.85 |
Last dorsal spine length | 10.39 | 10.19 | 11.16 | 9.12 | 7.95 | 5.87 | 5.03 |
Longest dorsal ray length (third) | 10.98 | 9.25 | 12.63 | 11.04 | 8.32 | 6.34 | 5.33 |
First anal spine length | 3.4 | 3.05 | 3.73 | 3.07 | 3.36 | 2.35 | 2.51 |
Second anal spine length | 7.74 | 7.12 | 8.18 | 8.06 | 6.81 | 4.75 | 4.85 |
Third anal spine length | 8.33 | 7.77 | 9.12 | 8.97 | 6.84 | 4.87 | 4.97 |
Longest anal ray length (third) | 9.98 | 10.77 | 12.72 | 12.4 | 7.58 | 6.61 | 5.45 |
Caudal fin length | 22.9 | 20.8 | 26.94 | 17.38 | 16.45 | 13.31 | 11.83 |
Pectoral fin length | 20.86 | 19.55 | 20.72 | 20.62 | 16.82 | 12.77 | 11.34 |
maxilla | 9.43 | 8.9 | 10.34 | 9.98 | 7.64 | 5.94 | 4.43 |
Meristics | |||||||
Dorsal spines | X | X | X | X | X | X | X |
Dorsal rays | 15 | 15 | 15 | 16 | 16 | 15 | 16 |
Anal spines | III | III | III | III | iii | III | iii |
Anal rays | 9 | 9 | 9 | 9 | 9 | 9 | 9 |
Pectoral rays | I 13 i | I 13 | I 13 i | I 14 | I 13 i | I 13 | I 13i |
Caudal rays | 9+7+6+8 | 9+7+6+9 | 9+7+6+8 | broken | 9+7+6+8 | 9+7+6+9 | 9+7+6+8 |
Pored lateral line scales | 24 | 23 | 23 | 25 | loosen | 26 | 23 |
Dorsal scale rows | 3 | 3 | 3 | 3 | 3 | 3 | 3 |
Ventral scale rows | 10 | 10 | 9 | 10 | 9 | 10 | 10 |
Gill rakers | 8+22 |
The COI gene sequence of Tosanoides aphrodite is 12.65% divergent from Tosanoides obama, and on average 14–20% divergent from other genera of Anthiadinae. Because we do not have sufficient representation for members of this subfamily, no phylogenetic tree is provided here. In addition to the unique characters presented in the diagnosis section, Tosanoides aphrodite also differs from Tosanoides filamentosus in having a shorter snout and larger orbit (4.9–7.1 and 2.5–3.3 vs 4.6 and 3.7 in HL, respectively). Tosanoides flavofasciatus differs from Tosanoides aphrodite in having a shorter fourth (2.55–2.75 vs. 2.02–2.40 in HL) and last (3.11–3.44 vs. 1.82 and 2.17 in HL) dorsal spine length, 7th dorsal ray the longest instead the third, smaller third anal spine (2.65–2.80 vs. 1.89–2.62 in HL), and longer pectoral fin length (2.36–2.71 vs. 2.72–3.05 in SL). Tosanoides obama also differs from Tosanoides aphrodite in having a shorter fourth (2.4–2.68 vs. 2.02–2.40 in HL), fifth (2.4–2.88 vs. 1.94–2.29 in HL) and last (2.67–3.06 vs. 1.82–2.17 in HL) dorsal spine length, 7th or 8th dorsal ray the longest instead the third, and longer pectoral fin length (2.49–2.63 vs. 2.72–3.05 in SL).
Initially, differences in counts, body proportions, morphology of dorsal and caudal soft rays, and distribution (a single locality in the Atlantic versus wide range in the Pacific Ocean) made us believe that T. aphrodite constituted a new genus. However, preliminary genetic analysis based on the COI gene placed T. aphrodite between two pairs of Tosanoides species (including an undescribed new species from Pohnpei, Micronesia; Pyle et al., submitted). Therefore, we provisionally place this new species in Tosanoides, but future genetic analyses with multiple loci might clarify the Anthiadinae classification and change the generic placement of T. aphrodite.
The isolation of Saint Paul’s Rocks, from both the American and African coastlines, and its extremely small size, are likely the main causes for the high endemism and low diversity in the local marine biodiversity. Previously, there were seven endemic reef fishes that were exclusively found at St. Paul’s Rocks, while another six restricted range species were shared with the Brazilian oceanic islands of Fernando de Noronha and Rocas Atoll (
This work was funded by the generous support of donors to the California Academy of Sciences’ Hope for Reefs Initiative. We also thank the crew of the M/V Alucia for their help and logistical support. Josh Copus and Richard Pyle provided tissue samples and valuable insights. We are grateful to many colleagues who helped in the field, lab, and with discussions: Bart Shepherd, Cristina Castillo, Mauritius V. Bell, Ronaldo Francini-Filho, Carlos Eduardo Ferreira, Abilio Soares Gomes, Steve Hudson. We would also like to thank Jon Fong for taking the radiographs and photos of the type specimens. D. Catania, J.C. Joyeux, I. Sazima, M. Pinna, and J. Williams helped access