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A New Mesophotic Clingfish (Teleostei: Gobiesocidae) from the Bahamas
John S. Sparks
1
and David F. Gruber
2
A new species of clingfish belonging to the genus Derilissus is described from a deep coral wall in the Exumas, Bahamas.
The new species is distinguished from congeners by a unique pigmentation pattern and coloration, the presence of 47
total pectoral-fin rays, a strongly convex posterior margin on disk region B, and by a unique arrangement of papillae on
disk region C. The new species is characterized by bright orangish-red coloration on the flank, a yellow head, and a
prominent black oval marking on the caudal peduncle. Like other members of the genus, the new species appears to be
restricted to the mesophotic zone, and was collected at 286 fsw.
WHILE conducting a series of deep research dives
in the Exumas, Bahamas, a diminutive and
brightly colored clingfish (Gobiesocidae) was
collected using rotenone on a wall dive at roughly 300 fsw.
Based on small adult size, fusion of the gill membranes to
the isthmus, and morphology of the sucking disk, it was
immediately clear that the specimen represented a new
species of the diminutive deepwater genus Derilissus Briggs,
1969.
Derilissus currently comprises four species, D. nanus Briggs,
1969, D. vittager Fraser, 1970, D. kremnobates Fraser, 1970,
and D. altifrons Smith-Vaniz, 1971, and was described by
Briggs (1969) to encompass a diminutive new species of
clingfish collected in relatively deep waters of the Bahamas
that differed from all other New World gobiesocids in
having the gill membranes fused to the isthmus. Soon
thereafter, three additional species of Derilissus were de-
scribed (Fraser, 1970; Smith-Vaniz, 1971), all from deeper
waters of the Western Atlantic.
Herein, we formally describe a new species of Derilissus
from a deep coral wall in the Exumas, Bahamas, western
Atlantic Ocean. Further, we discuss the apomorphic mor-
phological features that distinguish the new species from
congeners and other Bahamian gobiesocids.
MATERIALS AND METHODS
The holotype was collected using closed-circuit Trimix
rebreather SCUBA systems at a small rotenone station in
280–300 fsw on Bock Wall (23u49955.20N, 276u9910.440W),
near Lee Stocking Island, Exumas, Bahamas. The site is
characterized by a fringing barrier reef beginning at 70 fsw,
and dropping vertically to over 2000 fsw. The vertical ‘wall’
is comprised of a series of ledges and undercuts in roughly
30- to 50-foot intervals. A distinct overhanging ledge that
created a notch from 280 to 300 fsw was identified as a
target collection area. Rotenone was dispersed over this area,
and after 15 to 20 minutes affected specimens were located
with a compact light-emitting diode dive light, collected
using a small hand net, and individually bagged for
transport back to the surface. The specimens were immedi-
ately placed on ice to preserve coloration and photographed.
The holotype of the new species, the only individual that
could be collected, was one of a group of four or five of the
same species living in very near proximity to a small coral
head.
Osteological features of the new species and comparative
gobiesocid taxa were analyzed using radiographs, high-
resolution digital images, and via the examination of whole
specimens under a dissecting scope. Point-to-point morpho-
metric measurements were recorded to the nearest 0.1 mm
using dial calipers. Measurements follow Briggs (1955),
unless noted otherwise. Standard length (SL) is used
throughout. Vertebral count excludes the ural centrum
(5last half-centrum). Following Smith-Vaniz (1971), princi-
pal caudal rays are defined here as those attached to or
articulating with the hypurals, and are presented in the
formula ventral +dorsal. Disk width is measured at the
widest point of the pelvic disk. Institutional abbreviations
are as listed in Leviton et al. (1985) and Sabaj Pe´rez (2010).
Derilissus lombardii, new species
Figures 1, 2; Table 1
Holotype.—AMNH 251906, 10.9 mm SL, Exumas, Bahamas,
Bock Wall, 23u49955.20N, 276u9910.440W, 286 fsw near a
small coral head using Tri-mix mixed-gas closed-circuit
rebreather SCUBA systems, M. Lombardi, J. Godfrey, D. F.
Gruber, and J. S. Sparks, 4 May 2011.
Diagnosis.—AmemberofDerilissus distinguished from
congeners (and all other Bahamian gobiesocids) by the
presence of bright orangish-red coloration, a yellow head,
and a prominent black oval patch on the caudal peduncle.
The new species is further distinguished from congeners by
the pattern of papillae in disk region C (Fig. 2). Anteriorly,
two distinct medial clusters, each comprising 8–9 closely
arrayed papillae plus a single papilla anterior of each cluster,
are present (vs. 2–5 papillae in each central cluster and 4–5
papillae arranged in a distinct crescent posterolaterally in
congeners). Posteriorly, papillae in disk region C are
arranged in a crescent with a single additional papilla dorsal
to its midpoint (vs. papillae arranged in an inverted V-
shaped pattern in D. nanus,D. altifrons, and D. kremnobates,
or clumped in D. vittager). Uniquely among members of
Derilissus, the posterior margin of disk region B in the new
species is strongly convex (vs. straight to weakly convex in
congeners) with the rows of papillae arranged serially in a
semi-circular pattern forming concentric crescents (vs. rows
more or less straight). Lastly, the new species is unique
1
American Museum of Natural History, Department of Ichthyology, Division of Vertebrate Zoology, Central Park West at 79
th
Street, New
York, New York 10024; E-mail: jsparks@amnh.org. Send reprint requests to this address.
2
City University of New York, Baruch College, Department of Natural Sciences, 17 Lexington Avenue, New York, New York 10010; E-mail:
david.gruber@baruch.cuny.edu.
Submitted: 8 September 2011. Accepted: 12 January 2012. Associate Editor: D. Buth.
F2012 by the American Society of Ichthyologists and Herpetologists DOI: 10.1643/CI-11-124
Copeia 2012, No. 2, 251–256
among congeners in possessing a total of 47 pectoral-fin
rays.
Description.—Selected proportional measurements and me-
ristic data presented in Table 1. Comparatively, a very small
gobiesocid. Body moderately wide and rounded anteriorly,
becoming progressively laterally compressed posteriorly.
Caudal peduncle strongly laterally compressed. Head deep
and profile of snout strongly convex, not dorsoventrally
compressed, forming angle of about 75uin lateral view.
Mouth small and rostroventrally oriented. Margin of lower
jaw wider laterally, with moderate medial constriction at
symphysis in ventral view. Eye large, with distinctive
spotted ring. Anterior nostril tubular and elongate, without
dermal flap. Posterior nostril tubular and short. Pore system
on head well developed and as described by Fraser (1970:fig.
2) and Smith-Vaniz (1971) for other members of genus. Pore
system lacking on flank. Body asquamate.
Fig. 1. Derilissus lombardii, new species, holotype, AMNH 251906, 10.9 mm SL, Exumas, Bahamas. Images taken immediately following capture
illustrate live coloration. (A) Lateral view. (B) Dorsal view. (C) Ventral view.
252 Copeia 2012, No. 2
Upper jaw with two distinct rows of crowded, relatively
strongly tricuspid and bicuspid teeth anteriorly, grading to a
single row of weakly bicuspid and unicuspid teeth laterally and
posteriorly. Teeth in a single row in lower jaw, and procumb-
ently implanted. Lower jaw dentition strongly tricuspid
medially, becoming bicuspid laterally, and unicuspid posteri-
orly. Teeth more closely arrayed anteriorly, and becoming more
sparsely arranged posteriorlyinbothupperandlowerjaw.
Fin-ray counts as follows: dorsal 8; anal 7; pectoral 24 (left)
+23 (right) 547 total; pelvic I,4; and principal caudal rays
7+6 (procurrent rays could not be observed in radiographs).
Gill membrane attached to isthmus, and with fleshy,
dorsocaudally directed prong at about midpoint of opening.
Upper attachment of gill membrane is opposite approxi-
mately 9
th
pectoral-fin ray, and lower attachment is opposite
approximately 21
st
or 22
nd
pectoral ray. Membrane from last
pelvic ray loosely attached to approximately 20
th
or 21
st
pectoral ray. Vertebral count 25.
Four gill arches present on each side, with feeble fourth
arch closely aligned with lower pharyngeal bone. Gill arches
1–3 bear large, complex, brush-like filaments (which
strongly resemble the sea pen, Pennatula), whereas none
are present on fourth arch. Thin, relatively short and
triangular gill rakers present on all four arches. Five
branchiostegal rays present on each side, and arranged in
two distinct groups (1+4). Arrangement and articulation of
branchiostegals as described by Smith-Vaniz (1971:292).
Disk large, well developed, and single. Papillae numerous
and distributed in unique pattern. Arrangement of papillae in
disk region C appears to be phylogenetically informative
within Derilissus as observed by Smith-Vaniz (1971). As
shown in Figure 3, in D. nanus,D. kremnobates, and D.
altifrons papillae on posterior portion of disk region C
arranged in inverted V-shaped pattern (Smith-Vaniz,
1971:fig. 3a–c), whereas in D. vittager, papillae in region
more or less clumped (Smith-Vaniz, 1971:fig. 3d). In contrast,
in D. lombardii, new species, papillae on posterior portion of
disk region C form a crescent with single additional papilla
dorsal to its midpoint (Figs. 1C, 2). Anteriorly in D. lombardii,
two distinct circular medial clusters, each comprising 8–9
closely arrayed papillae plus a single papilla anterior of each
cluster, present (vs. 2–5 papillae in each central cluster and 4–
5 papillae arranged in a separate and distinct crescent
posterolaterally in congeners; Fig. 3). Posterior margin of
disk region B strongly convex with rows of papillae in region
serially arranged in semi-circular pattern forming concentric
crescents (Figs. 1C, 2).
Coloration and pigmentation pattern in life.—Photographed
while fresh and coloration in life represented in Figure 1.
Overall, body bright yellow to orangish-red. Flank bright
orangish-red along midline and ventrally. Yellow to light
orange above midline. Faint orange vertical bars visible on
flank, particularly dorsally. Jaws, snout, and head bright
yellow. Throat light grayish-white to pale yellow. Dorsal
aspect of body mostly bright orange from about mid-orbit to
origin of dorsal fin. Distinctive orange spotting in interor-
bital region and extending slightly posterior to nape. Dark
orangish-red patch posterior to orbit. Black eye ring with
golden and orangish speckling. Distinctive black oval
marking on caudal peduncle. Pelvic disk hyaline to pale
yellow, and peppered with numerous bright orange papillae.
Pectoral fin bright yellow. Dorsal, anal, and caudal fin
hyaline with reddish spotting, particularly distally.
Coloration and pigmentation pattern in alcohol.—Similar to
that described above for coloration in life, except that
Table 1. Morphometric and Meristic Data for Holotype of
Derilissus lombardii.
Character
Standard length (mm) 10.9
Percentage of SL
Head length 38.5
Head width 30.3
Body depth 24.8
Snout length 12.8
Eye length 11.9
Interorbital width (IOW) 10.1
Pelvic disk length 35.8
Pelvic disk width 25.7
Caudal peduncle depth (CPD) 11.0
Caudal peduncle length (CPL) 7.3
Percentage of HL
Snout length 33.3
Eye length 31.0
Interorbital width (IOW) 26.2
Eye length %IOW 118.2
CPD %CPL 150.0
Meristics
Dorsal fin 8
Anal fin 7
Pectoral fin 24(L) +23(R)
Pelvic fin I, 4
Principal caudal rays 7 +6
Vertebrae 25
Fig. 2. Schematic of sucking disk of holotype of Derilissus lombardii,
AMNH 251906, showing distribution of papillae. Papillae in disk region
C are indicated by solid black circles.
Sparks and Gruber—New mesophotic clingfish from the Bahamas 253
Fig. 3. Ventral view illustrating pattern of papillae on disk in: (A) Derilissus kremnobates, holotype, ANSP 109625; (B) D. altifrons, holotype, ANSP
112690; (C) D. vittiger, holotype, ANSP 109626; (D) D. nanus, holotype, UF 15932.
254 Copeia 2012, No. 2
yellow, orange, and reddish coloration fades significantly in
ethanol. Prominent black oval blotch on caudal peduncle
still detectable in preservation.
Habitat and distribution.—Although described from a single
specimen collected on a deep, mesophotic reef near Lee
Stocking Island in the Exumas, Bahamas, the holotype was
one of a group of four or five individuals living proximate to
a small coral head on an outcrop above an undercut and
ledge in 286 fsw (Fig. 4); however, these additional speci-
mens could not be collected. Additional images of the
habitat of the new species can be observed on the
Mesophotic Coral Ecosystems website (www.mesophotic.
org/index.php?page5photos&photographerid5272). Given
that deep mesophotic reefs have only recently become
accessible via technical SCUBA, it is impossible at this time
to speculate on the geographic range of the new species.
Etymology.—Named after the collector of holotype, Michael
Lombardi, who was part of the deep diving team, along with
Jeff Godfrey, on our Bahamas expedition. Specific epithet,
lombardii, to be treated as a noun in apposition.
Remarks and comparisons.—Although it may seem somewhat
surprising to find a new clingfish in the Bahamas, particu-
larly near Lee Stocking Island, given the significant amount
of ichthyological survey work that has taken place in the
region (e.g., Bo¨hlke, and Chaplin, 1968, 1993; Smith-Vaniz
and Bo¨hlke, 1991), small reclusive fishes on deep mesopho-
tic reefs are difficult to access and observe, and even more
difficult to collect. Due to their frequent cryptic coloration,
small size, and elusive behavior, gobiesocids are frequently
overlooked and remain undetected even in easily accessible
habitats, such as shallow intertidal regions (Craig and
Randall, 2009). It is, therefore, not surprising that new
species of deep water, reef-associated fishes continue to be
discovered in regions that have otherwise been subjected to
a significant amount of ichthyological survey work, given
that mesophotic communities, light-dependent coral com-
munities occurring in the lower reaches of the photic zone,
have only recently become accessible via technical diving
methods.
The new species seems to be closely associated with deep
reefs, not straying far from the safety of a coral head. Other
species of Derilissus have been captured in trawls, suggesting
that they are more open water benthic taxa. All species in
the genus are known only from relatively deep water (45–
266 m; 148–873 fsw) compared to other gobiesocids.
In addition to apomorphic features of the pelvic disk
discussed in detail above and the number of pectoral-fin
rays, the new species is readily distinguished from congeners
based on its vivid orangish-red coloration, yellow head, and
prominent black oval marking on the caudal peduncle. Both
D. kremnobates and D. vittager are characterized by chain-like
patterns on the flank (vs. broad vertical bars and spotting in
D. lombardii), and radiating streaks around the orbit in D.
kremnobates, or dark lines on the head in D. vittager (vs. solid
coloration or faint spotting in D. lombardii). Deilissus nanus
Fig. 4. Deep reef habitat on Bock Wall, Exumas, Bahamas. The holotype of the new species was collected from the outcrop near the top of the image
(image taken at approximately 300 fsw). Image by Michael Lombardi.
Sparks and Gruber—New mesophotic clingfish from the Bahamas 255
is reportedly black on the sides, grading to brownish above
(Briggs, 1969). Derilissus kremnobates has two pale spots on
the caudal membrane (Fraser, 1970:fig. 4), whereas D.
vittager possesses dark blotches anteriorly on both the dorsal
and anal membranes (Fraser, 1970:fig. 5). In contrast, these
regions are hyaline in D. lombardii. The new species is
unique in possessing a large black oval marking midlaterally
on the caudal peduncle.
Although coloration in life is unknown for D. altifrons,
some faint, diffuse pigmentation can be seen in the caudal
region of the holotype (ANSP 112690), particularly dorsally
(also see Smith-Vaniz, 1971:fig. 1). After several months in
ethanol the black caudal marking in D. lombardii, new
species, is still visible, although much of the remaining
pigmentation in this specimen has faded. Given the
persistence of the caudal marking in the new species in
preservation and the distribution of what little pigment
remains in the holotype of D. altifrons, it seems likely that D.
altifrons did not possess a large, prominent black midlateral
marking spanning the length of the caudal peduncle in life
(Fig. 1). Regardless, the new species is readily distinguished
from D. altifrons by a number of features already discussed,
including a lower pectoral ray count (47 vs. 52 in D.
altifrons), two distinct rows of teeth in the upper jaw (vs.
single row in D. altifrons), and tricuspid teeth in both upper
and lower jaws (vs. bicuspid in D. altifrons).
MATERIAL EXAMINED
Gobiesocids used in comparative analyses arranged alpha-
betically, with additional relevant information presented for
other members of Derilissus.
Acyrtops beryllinus: AMNH 34410, 6 ex., Bahamas; AMNH
87230, 1 ex., Florida; AMNH 225258, 1 ex., Bahamas.
Acyrtus artius: AMNH 18568, 3 ex., Bahamas; AMNH 30005,
1 ex., Bahamas; AMNH 31186, 2 ex., Bahamas.
Acyrtus rubiginosus: AMNH 23998, 32 ex., Bahamas; AMNH
24990, 54 ex., Bahamas; AMNH 34248, 69 ex., Bahamas; AMNH
249672, 2 ex., Bahamas; AMNH 250336, 1 ex., Bahamas.
Arcos macrophthalmus: AMNH 239026, 2 ex., Bahamas;
AMNH 249673, 1 ex., Bahamas.
Derilissus altifrons: ANSP 112690, holotype, 17.1 mm SL,
Dominica Channel, western Atlantic, 15u13.09N, 60u56.99W,
depth 68–69 m.
Derilissus kremnobates: ANSP 109625, holotype, 27.6 mm SL,
Arrowsmith Bank, Caribbean Sea, 21u059N, 86u239W, depth
80–145 fm.
Derilissus nanus: UF 15932, holotype, 13.5 mm SL, off West
Plana Cay, Bahamas, depth 48–51 m.
Derilissus vittiger: ANSP 109626, 18.6 mm SL, Venezuela,
11u01.89–11u01.09N, 65u34.29–65u36.39W, depth 37 fm.
Gobiesox lucayanus: AMNH 21270, 2 ex., Bahamas.
Gobiesox punctulatus: AMNH 19962, 1 ex., Bahamas; AMNH
28970, 1 ex., Bahamas; AMNH 30939, 1 ex., Antigua; AMNH
33232, 1 ex., Bahamas.
Tomicodon cryptus: AMNH 237341, 1 ex., Venezuela; AMNH
238924, 1 ex., Curacao.
Tomicodon fasciatus: AMNH 249671, 4 ex., Bahamas; AMNH
249710, 1 ex., Bahamas.
Tomicodon reitzae: AMNH 237345, 1 ex., Venezuela; AMNH
249277, 1 ex., Venezuela.
Tomicodon rupestris: AMNH 239048, 1 ex., Curacao; AMNH
239051, 1 ex., Curacao.
ACKNOWLEDGMENTS
We offer our sincere gratitude to our deep-diving team on
the expedition, M. Lombardi (Ocean Opportunity) and J.
Godfrey (UCONN), who generously collected for us on their
exploratory dives and, as a result, discovered the new
species. We are grateful to the Lee Stocking Island Marine
Institute for logistical support and for assistance with
permits. Thanks to K. Conway (TAMU) for generously
sharing his knowledge of gobiesocids and confirming the
generic placement of the new species, and to R. Schelly and
R. Arrindell (AMNH) for assistance with radiographs. For the
loan of specimens in their care, digital images, and
radiographs, we are grateful to K. Luckenbill, M. Sabaj, and
J. Lundberg (ANSP), and Z. Randall and L. Page (UF). All
research was conducted in accordance with American
Museum of Natural History (AMNH) IACUC guidelines.
This study was supported by Waitt awards from the National
Geographic Society (W140-10) to M. Lombardi and (W101-
10) to D. Gruber, Ocean Opportunity, Inc., the AMNH, New
York, and the National Science Foundation through an
award to JSS (IOS-0749943).
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