Research Article |
Corresponding author: Luke Tornabene ( luke.tornabene@gmail.com ) Academic editor: Caleb McMahan
© 2023 Katlyn M. Fuentes, Carole C. Baldwin, D. Ross Robertson, Claudia C. Lardizábal, Luke Tornabene.
This is an open access article distributed under the terms of the CC0 Public Domain Dedication.
Citation:
Fuentes KM, Baldwin CC, Robertson DR, Lardizábal CC, Tornabene L (2023) Two new species of Varicus from Caribbean deep reefs, with comments on the related genus Pinnichthys (Teleostei, Gobiidae, Gobiosomatini, Nes subgroup). ZooKeys 1180: 159-180. https://doi.org/10.3897/zookeys.1180.107551
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Tropical deep reefs (~40–300 m) are diverse ecosystems that serve as habitats for diverse communities of reef-associated fishes. Deep-reef fish communities are taxonomically and ecologically distinct from those on shallow reefs, but like those on shallow reefs, they are home to a species-rich assemblage of small, cryptobenthic reef fishes, including many species from the family Gobiidae (gobies). Here we describe two new species of deep-reef gobies, Varicus prometheus sp. nov. and V. roatanensis sp. nov., that were collected using the submersible Idabel from rariphotic reefs off the island of Roatan (Honduras) in the Caribbean. The new species are the 11th and 12th species of the genus Varicus, and their placement in the genus is supported by morphological data and molecular phylogenetic analyses. Additionally, we also collected new specimens of the closely-related genus and species Pinnichthys aimoriensis during submersible collections off the islands of Bonaire and St. Eustatius (Netherland Antilles) and included them in this study to expand the current description of that species and document its range extension from Brazil into the Caribbean. Collectively, the two new species of Varicus and new records of P. aimoriensis add to our growing knowledge of cryptobenthic fish diversity on deep reefs of the Caribbean.
Gobies, ichthyology, mesophotic, molecular systematics, phylogenetics, rariphotic, submersible
Deep reefs occur worldwide in tropical and subtropical regions at depths ranging from approximately 40 m to at least 300 m (
Presently, there is not only a lack of studies focused on fish communities spanning the entire depth range of deep reefs, but also on cryptobenthic reef fishes that reside in these ecosystems (
One group of cryptobenthic reef fishes that are well-represented throughout shallow and deep reefs, are gobies (Gobiidae). Gobies are among the most diverse families of marine fishes, and with more than 160 known species in the Greater Caribbean, are the most diverse family of shorefishes in that region. These fishes exhibit a variety of morphological and behavioral adaptations that have allowed them to thrive in aquatic ecosystems worldwide (
Here we describe two new species representing the 11th and 12th species of the genus Varicus based on two specimens collected in 2018 from Roatan, Honduras. Additionally, we provide comments to expand the current species description of P. aimoriensis based on two specimens collected in 2017 by DROP from Bonaire and Sint Eustatius, as well as updated scale counts from the type specimens. The two new specimens are nearly 6000 km from the type locality of P. aimoriensis and were collected at greater depths than the original types (96 m and 164 m versus 70 m).
The new species of Varicus (UW 158119 and UW 158127) were collected off the coast of Half Moon Bay, Roatan, Honduras, using the Idabel submersible, which accommodates three people (one pilot and two passengers) and has a maximum depth rating of 915 m. Prior to capture the specimens were sedated with a solution of quinaldine-sulfate in sea water, which was dispersed via a pump through a tube on the front of the submersible. Sedated specimens were then collected by a suction hose powered by one of the sub’s vertical thrusters and stored in an acrylic collection tank attached to the sub until they were brought to the surface (see
Two specimens of Pinnichthys (USNM 442071 and USNM 442696) were collected via the Curasub submersible off the coasts of Bonaire and St. Eustatius. Additional P. aimoriensis paratypes (AMNH 265021, AMNH 265020) were also examined. Discrepancies in the number of transverse scale rows between the type specimens and the original description were noted and are corrected here (see Table
All measurements were taken using digital calipers to the nearest 0.1 mm, and all morphological characters analyzed here are defined by
Methods for DNA analysis follow those of
The molecular phylogenetic analysis shows strong support for monophyly of the tribe Gobiosomatini, the Gobiosoma group, and the Nes subgroup (Fig.
All three specimens of Pinnichthys aimoriensis are recovered as a monophyletic group with strong support (posterior probability = 1.0). The specimen from Bonaire is most closely related to the holotype from Brazil, with the specimen from St. Eustatius being sister to them on a comparatively longer branch. However, we were only successful in amplifying partial segments of two out of four genes and (1551 out of 4389 bp, or 64.6% missing data), so we are cautious about our interpretation of the exact position and branch lengths for this specimen.
Roatan, Honduras; western Caribbean.
Honduras • 1 female 30.5 mm SL; western Caribbean, island of Roatan, west End, off Half Moon Bay, sta. IDABEL18-02; 16.304°N, 86.598°W; 247 m depth; 5 June 2018; Luke Tornabene, D. Ross Robertson and Karl Stanley; 5% quinaldine-sulfate dispersed from Idabel submersible; UW 158119, DNA sample ROA18032.
In addition to molecular characters supporting the phylogenetic placement of this species, the following morphological characters support its inclusion in the genus Varicus (sensu
Varicus prometheus is distinguishable from all other Varicus species by the following combination of characters: second dorsal fin I,9; anal fin I,8; pectoral fin 17; scales absent except for two modified basicaudal scales; pelvic rays 1–4 unbranched without fleshy tips; one anal-fin pterygiophore inserted anterior to first haemal spine (but see ‘Remarks’ section below); body with four incomplete brown saddles on pale to bright yellow background; pelvic and pectoral fins white to pale yellow in life, dorsal, anal, and caudal fins pale to bright yellow.
General shape : body robust, widest and deepest at posterior of head, trunk tapering in width and depth posteriorly, dorsal profile of head gently sloping from dorsum to tip of snout.
Morphometrics (%SL) : head length 26.9; eye diameter 7.5; snout length 7.5; upper-jaw length 12.8; post-orbital length 13.1; predorsal length 36.7; body depth at 1st dorsal-fin origin 18.7; body depth at anal-fin origin 17.0; preanal length 61.0; body depth at caudal peduncle 10.5; caudal-peduncle length 12.1; pectoral-fin length 32.8; pelvic-fin length 25.6.
Median and paired fins : first dorsal fin VII; second dorsal fin I,9; anal fin I,8; pectoral fin 17; pelvic fins I,5, fins well separated, lacking both anterior frenum and membrane connecting bases of innermost rays; 4th pelvic-fin ray longest, extending posteriorly to base of anal-fin spine; rays 1–4 all unbranched, no fleshy tips; 5th ray unbranched and <10% the length of the 4th ray; caudal fin shape undeterminable due to poor condition of specimen, branched caudal-fin rays 13, segmented caudal-fin rays 17.
Vertebral skeleton (Fig.
Head : jaw terminal, angled approximately 45 degrees from horizontal axis of the body, extending posteriorly to vertical through anterior margin of pupil; anterior nares on a short tube, posterior nares small, barely visible as an opening on a slightly raised rim immediately anterior to eye; eyes large, dorsolateral, extending to dorsal profile of head; operculum opening slightly wider than width of pectoral-fin base; teeth difficult to accurately assess due to condition of specimen, teeth in both upper and lower jaws in multiple rows, two to three rows anteriorly, with outer row in upper jaw slightly enlarged with recurved canines.
Sensory papillae (Fig.
Squamation : scales on head and body absent except for two modified basicaudal scales with enlarged ctenii present at dorsal and ventral margins of caudal-fin base.
Genitalia : female with short, slightly rounded, conical papilla, wider at base and tapering to a slight point; male unknown.
Color before preservation (Fig.
Color in preservation (Fig.
The holotype was collected at from the deep-reef slope at 247 m on sand with Halimeda rubble.
Known only from the type locality off Roatan, Honduras.
The specific epithet prometheus is a patronym in reference to the Greek god Prometheus. In Greek mythology, as punishment from the god Zeus, Prometheus had his liver eaten out by an eagle, only to have the liver grow back overnight so it might be eaten again the next day. The name refers to the fact that the abdomen of the holotype of the new species was partially eaten by a hermit crab. The name is treated as a noun in apposition.
Varicus prometheus most likely possesses 27 total vertebrae, like all other species in genus. However, our radiographs did not have enough resolution for us to determine whether the 12th vertebra had a haemal spine (if present, it is very reduced) rendering it the first caudal vertebra versus the last precaudal vertebra (Fig.
Varicus prometheus is easily distinguished from other species of Varicus and species in the morphologically similar genus Psilotris (Table
Live or fresh coloration of Varicus species (coloration unknown for V. benthonis and V. bucca) A V. adamsi, photo by L. Tornabene B V. cephalocellatus, photo by B. Brown C V. decorum, photo by B. Brown D V. lacerta, photo by C. Baldwin E V. marilynae, illustration by R. G. Gilmore F V. veliguttatus, photo by C. Baldwin G V. nigritus, illustration by R. G. Gilmor H V. vespa, photo by the crew of the R/V BELLOWS.
Important taxonomic characters for the genera Varicus, Psilotris and Pinnichthys.
Species | Second dorsal | Anal | Pectoral | AP | Pelvic rays 1–4 | Papillae rows 5i/5s | Lateral scale rows | Basicaudal Scales |
---|---|---|---|---|---|---|---|---|
Varicus prometheus sp. nov | I,9 | I,8 | 17 | 1 | unbranched | connected | absent | present |
Varicus roatanensis sp. nov | I,8 | I,8 | 17 | ? | unbranched | ? | 28 | present |
Varicus adamsi | I,9 | I,7–8 | 18 | 1 | branched – fleshy pads | connected | 21–24 | present |
Varicus benthonis | I,8 | I,7 | 16 | 1 | branched | separate | 12 | present |
Varicus bucca | I,9 | I,7–8 | 16–19 | 1 | unbranched or branched – fleshy pads | connected | 27 | present |
Varicus cephalocellatus | I,10 | I,9 | 19–20 | 1 | unbranched | variable | 12–23 | present |
Varicus decorum | I,9 | I,7–8 | 17 | 1 | unbranched | connected | absent | present |
Varicus lacerta | I,9 | I,7 | 18 | s | branched – feathery | connected | absent | absent |
Varicus marilynae | I,8 | I,7 | 16–18 | 1 | branched – fleshy pads | connected | 18–19 | present |
Varicus nigritus | I,9 | I,8 | 17 | 1 | unbranched | connected | present (exact count unknown) | present |
Varicus veliguttatus | I,8 | I,6–7 | 17–19 | 1 | unbranched | connected | 23–34 | present |
Varicus vespa | I,9 | I,7 (rarely I,6 or I,8) | 15–17 | 1 | branched – fleshy pads | separate | 9–14 | present |
Psilotris alepis | I,9 (rarely I,8) | I,7–8 | 15 | 2 | branched | separate | absent | absent |
Psilotris boehlkei | I,9–10 | I,9 | 16–18 | 2 | branched | separate | absent | absent |
Psilotris celsa | I,9–10 (rarely I,8) | I,9–10 (rarely I,8) | 16–17 | 2 | branched | connected | absent | absent |
Psilotris kaufmani | I,10 (rarely I,9) | I,10 (rarely I,9) | 16–19 | 2 | branched | connected | absent | absent |
Psilotris laetarii | I,9–10 | I,7–8 | 15–17 | 2 | branched | connected | absent | absent |
Psilotris laurae | I,9 | I,8 | 18 | 1 | branched | connected | absent | absent |
Psilotris vantasselli | I,9 | I,8 | 15 | 1 | branched | connected | absent | present |
Pinnichthys aimoriensis | I,10–11 | I,10 | 18–19 | 2 | branched | connected | 40–47 | present |
Pinnichthys bilix | I,11 | I,10–11 | 19–20 | 2 | branched | connected | 30–35 | present |
Pinnichthys prolata | I,10–11 | I,10–11 | 17–19 | 2 | branched | connected | 34–37 | present |
Pinnichthys saurimimica | I,11 | I,11 | 20 | 2 | branched | connected | 47–53 | present |
Pinnichthys atrimela (Pacific) | I,11 | I,10 | 20 | 2 | branched | connected | 41 | present |
Roatan, Honduras; western Caribbean.
Honduras • 1 female 18.5 mm SL; western Caribbean, island of Roatan, west End, off Half Moon Bay, sta. IDABEL18-03; 16.304°N, 86.598°W; 237 m depth; 6 June 2018; Luke Tornabene, Rachel Manning, and Karl Stanley; 5% quinaldine-sulfate dispersed from Idabel submersible; UW 158127, DNA sample ROA18043.
In addition to the molecular characters supporting the phylogenetic placement of this species, the following morphological characters support its inclusion in the genus Varicus: first dorsal spines VII; vertebrae 11+16; dorsal pterygiophore formula 3-221110; anal-fin rays I,9 or fewer (I,8 in V. roatanensis); head pores absent; pelvic fins completely separate, lacking both anterior frenum and membrane connecting bases of innermost pelvic-fin rays; fifth pelvic-fin ray unbranched.
Varicus roatanensis is distinguishable from all other Varicus species by the following combination of characters: second dorsal fin I,8; anal fin I,8; pectoral fin 17; body scaled with 28 lateral rows of ctenoid scales, modified basicaudal scales present; pelvic rays 1–4 unbranched; body white with a series of elongate yellow dashes along lateral midline with scattered yellow spots between lateral midline and dorsal midline; dorsal and caudal fins white with bright yellow spots in life, pectoral, pelvic, and anal fins white.
General shape: body widest and deepest at the head, trunk tapering in width and depth posteriorly, dorsal head profile moderately sloping from dorsum to tip of snout.
Morphometrics (%SL) : head length 30.3; eye diameter 10.8; snout length 5.9; upper-jaw length 10.3; post-orbital length 13.5; predorsal length 40.0; body depth at 1st dorsal-fin origin 15.1; body depth at anal-fin origin 12.4; preanal length 54.1; body depth at caudal peduncle 9.2; caudal-peduncle length 9.2; pectoral-fin length 20.5; pelvic-fin length 25.9.
Median and paired fins : first dorsal fin VII; second dorsal fin I,8; anal fin I,8; pectoral fin 17; pelvic fins I,5, fins well separated, lacking both anterior frenum and membrane connecting bases of innermost rays; 4th pelvic-fin ray longest, extending posteriorly to anus; rays 1–4 connected by a thin membrane, all unbranched without fleshy tips; 5th ray unbranched and approximately 25% the length of the 4th ray; caudal fin damaged, unable to determine fin-shape, branched caudal-fin rays13, segmented caudal-fin rays 17.
Vertebral skeleton : 27 vertebrae, 11 precaudal, and 16 caudal; dorsal pterygiophore formula 3-221110, unknown number of anal-fin pterygiophores inserted anterior to 1st haemal spine, as radiographs were unclear.
Head : jaw terminal, angled approximately 50 degrees from the horizontal axis of body, extending posteriorly to vertical anterior end of pupil; anterior naris on elongate tube, posterior naris barely visible as an opening on a slightly raised rim immediately anterior to eye; eyes large, dorsolateral, extending slightly above head profile; narrow interorbital space, operculum opening slightly larger than pectoral fin base; condition and presence/absence of teeth undeterminable due to condition of specimen.
Sensory papillae : skin of holotype is heavily abraded and no papillae are visible on the head or body.
Squamation : trunk covered with ctenoid scales, extending anteriorly to pectoral-fin base; 28 scales in lateral series, approximately 9 or 10 transverse scale rows; no scales on head; 2 modified basicaudal scales with enlarged ctenii present at dorsal and central margins at base of caudal-fin.
Genitalia : female with short, rounded papilla, wider at base and tapering to a slightly conical point; male unknown.
Color before preservation (Fig.
Color in preservation (Fig.
Collected at 237 m. Specimen found on a silt-covered boulder with small 3–10 cm diameter caves and crevices.
Known only from the type locality off Roatan, Honduras.
The specific epithet roatanensis refers to the type locality, Roatan, Honduras.
(Table
Sint Eustatius • 1 male 19.5 mm SL; eastern Caribbean, SW side of island, Kay Bay, South and Southeast of R/V Chapman Mooring, sta. CURASUB17-17; 17.4600°N, 62.9816°W; 96.3 m depth; 15 April 2017; C. Baldwin, L. Tornabene, B. Brandt, and J. Casey; quinaldine dispersed from Curasub submersible; USNM 442696, DNA sample EUS17043. BONAIRE • 1 female 28.6 mm SL; southern Caribbean, Belnem, South of Punt Vierkant, sta. CURASUB17-08; 12.095°N, 68.2966°W; 162–164 m depth; 17 January 2017; C. Baldwin, L. Tornabene, B. Brandt, T. Devine; quinaldine dispersed from Curasub; USNM 442071, DNA sample BON17071.
Data from the two additional specimens examined expand upon the known morphological variation within Pinnichthys aimoriensis (Table
Comparison of new data for Pinnichthys aimoriensis and data from the type series. Values for new specimens that are outside the range of the type series are in bold.
USNM 442696 | USNM 442071 | CIUFES 2414 (holotype) | All types | |
---|---|---|---|---|
SL | 19.5 | 28.6 | 22.4 | 16.4–22.4 |
Sex | male | female | male | 2 males, 1 female |
Morphometrics in % SL | ||||
Eye diameter | 9.2 | 8.4 | 8.7 | 8.6–9.15 |
Jaw length | 9.7 | 10.1 | 9.6 | 9.6–11.5 |
Snout length | 6.2 | 5.6 | 5.8 | 5.2–7.0 |
Head length | 23.6 | 29.7 | 27.9 | 27.9–29.5 |
Postorbital length | 10.3 | 14 | 13.5 | 13.5–16.6 |
Depth at first dorsal-fin origin | 17.4 | 18.5 | 16.3 | 15.8–16.5 |
Depth at anal-fin origin | 17.4 | 17.1 | 17.3 | 14.6–17.3 |
Least caudal peduncle depth | 9.7 | 11.2 | 12.5 | 10.4–12.5 |
Caudal peduncle length | 15.4 | 17.5 | 22.9 | 18.8–23.0 |
Caudal-fin length | 23.4 | 22.21 | 26.3 | 26.3–27.8 |
Pectoral-fin length | 16.8 | 26.2 | 20.9 | 19.8–25.0 |
First dorsal-fin elements | VII | VII | VII | VII |
Second dorsal-fin elements | I,11 | I,11 | I,10 | I,10 |
Anal-fin elements | I,10 | I,10 | I,10 | I,10 |
Pectoral-fin rays | 19 | 19 | 18/19 | 18–19 |
Caudal-fin rays segmented, branched | 17, 15 | 17,14 | 17;14 | 17;14 |
Pelvic-fin elements | I,V | I,V | I,V | I,V |
Length of fifth pelvic-fin ray relative to fourth | 3/4 | 1/2 | 1/2 | 1/2 |
Vertebrae – precaudal + caudal | ? | 11+16 | 11+16 | 11+16 |
Dorsal-fin pterygiophore pattern | ? | 3-221110 | 3-221110 | 3-221110 |
Anal-fin pterygiophores inserted before haemal arch | ? | 2 | 2 | 2 |
Pelvic fins 1–4 | branched, no fleshy tips | branched, no fleshy tips | branched, no fleshy tips | branched, no fleshy tips |
Lateral scale rows | 43 | 47 | 40–45* | 40–47 |
Tranverse scale rows | 11 | 14 | 10** | 10–13** |
Side of body with 40–47 scale rows extending anteriorly to pectoral base; modified basicaudal scales present; first dorsal fin VII, without notably elongate spines, second dorsal I,10–11; anal fin I,10, rays fork only once near tips; pelvic fins well separated, no anterior frenum and no membrane connecting base of innermost rays; fifth pelvic-fin ray one half to three quarters the length of the fourth and unbranched; pelvic-fin rays 1–4 branched, without fleshy tips; papillae rows 5s and 5i separate, lacking a papilla that would result in their forming a single continuous transverse row; interorbital papillae row pb’, pc’, and pe’ present; head and preopercle canals and pores absent; two anal-fin pterygiophores inserted anterior to haemal arch.
Color before preservation (Figs
The type series off Espírito Santo, Brazil was collected near the Peroá natural gas platform at 70 m depth on a substrate of rhodoliths and other calcareous substrate. The Bonaire specimen was collected at 164 m on a moderately steep slope with short rock ledges, small caves and crevices – all of which were covered with fine sand. It was collected alongside two specimens of Varicus decorum. The St. Eustatius specimen was collected on a sand and Halimeda rubble substrate in close proximity to an Ircinia sp. sponge and several ~1 m diameter boulders covered with encrusting algae and sponges.
The data presented here for the two Caribbean specimens of Pinnichthys aimoriensis increase the range of several morphological characters, including the number of elements in the second dorsal fin (was I,10, now I,10–11). Pinnichthys aimoriensis can be distinguished from P. bilix (Hastings & Findley, 2013) and P. prolata (Hastings & Findley, 2015) in having more lateral scale rows (40–47 vs 30–37). Pinnichthys aimoriensis lacks the elongate dorsal spines that are present in P. bilix, and lacks the elongate fifth pelvic ray present in P. prolata (fifth pelvic ray falling well short of anus when adpressed, versus reaching anus or beyond in P. prolata). Pinnichthys aimoriensis can be futher distinguished from P. saurimimica Gilmore, Van Tassell & Tornabene, 2016, in having fewer lateral scale rows (40–47 vs. 47–53) and fewer pectoral-fin rays (18–19 vs 20), and in live coloration (Figs
We thank Bruce Brandt, Barry Brown, Cristina Castillo, Loretta Cooper, Tico Christiaan, Tommy Devine, Jordan Casey, Brian Horne, Jordy Stolk, Rob Loendersloot, Laureen Schenk, Adriaan “Dutch” Schrier, Barbara van Bebber, and the crew of the R/V Chapman for their assistance with field work. We thank Karl Stanley (Roatan Institute of Deep Sea Exploration) and Thomas Trudel for facilitating submersible diving in Roatan. We also thank Rachel Manning for help in the field, as well as Katherine Maslenikov (UW) and Diane Pitassy (USNM) for help with the curation of museum specimens. We thank Sam Ghods and Emily McFarland from the University of Washington for their assistance with molecular work. Portions of the laboratory and/or computer work were conducted in and with the support of the L.A.B. facilities of the National Museum of Natural History. This study is Ocean Heritage Foundation/Curacao Sea Aquarium/Substation Curacao contribution number OHF/CSA/SC#54.
The authors have no conflict of interests to declare.
All specimens were collected with appropriate research permits, which are held on file at the University of Washington. Collection of fishes was conducted following IACUC protocol # PROTO201800092.
This project was funded in part by the School of Aquatic and Fishery Sciences Capstone Program, the William W. and Dorothy T. Gilbert Ichthyology Research Fund, the Smithsonian’s Consortium for Understanding and Sustaining a Biodiverse Planet, the Smithsonian’s Competitive Grants for the Promotion of Science Program, the Herbert R. and Evelyn Axelrod Endowment Fund for Systematic Ichthyology, the National Geographic Society’s Committee for Research and Exploration (Grant #9102-12), and the Prince Albert II of Monaco Foundation. Portions of the laboratory and/or computer work were conducted in and with the support of the L.A.B. facilities of the National Museum of Natural History.
KMF and LT wrote the final draft of the paper. All authors contributed edits and comments on the final draft. CCL facilitated collections in Roatan. CCB, LT and DRR collected samples. KMF collected and analyzed data. CCB, DRR, CCL and LT designed the study. CCB and LT provided funding.
Carole C. Baldwin https://orcid.org/0000-0002-2875-0474
D. Ross Robertson https://orcid.org/0000-0003-3972-149X
Claudia C. Lardizábal https://orcid.org/0000-0002-2802-7593
Luke Tornabene https://orcid.org/0000-0002-0673-2320
All of the data that support the findings of this study are available in the main text or Supplementary Information.
Species | Catalog number | GenBank cytb | GenBank rag1 | GenBank sreb2 | GenBank zic1 |
---|---|---|---|---|---|
Pinnichthys aimoriensis | USNM 442696 | OR437371 | OR437374 | NA | NA |
Pinnichthys aimoriensis | USNM 442071 | OR437372 | OR437375 | OR437377 | NA |
Varicus prometheus | UW 158119 | OR437370 | NA | NA | OR437379 |
Varicus roatanensis | UW 158127 | OR437369 | OR437373 | OR437376 | OR437378 |
Maximum clade credibility tree from Bayesian analysis with all samples
Data type: tre
Explanation note: The maximum clade credibility tree summarized from post-burnin trees of the MrBayes analysis.