Eviota santanai, a new Dwarfgoby from Timor-Leste (Teleostei: Gobiidae)
Author
Greenfield, David W.
Author
Erdmann, Mark V.
text
Zootaxa
2013
3741
4
593
600
journal article
10.11646/zootaxa.3741.4.9
6da74c9b-e13a-4008-8bfd-c0e49b249ca9
1175-5326
223648
E8A2187A-B3EC-4542-965D-39C9F39B177B
Eviota santanai
n. sp.
Santana’s Dwarfgoby
Figs. 1–3
.
Eviota
species 1 Allen & Erdmann 2013: 79.
Holotype
:
CAS 234966,
11.8 mm
male, Tutuala,
Timor-Leste
,
08°21.723’S
,
127° 04.488’E
,
8 m
, M.V. Erdmann,
16 August 2012
.
Paratypes
: USNM 410587,
12.8 mm
male, taken with
holotype
; CAS 235688,
11.5 mm
male,
10.7 mm
female,
Pulau
Atauro,
Timor-Leste
,
08°13.281’S
,
125° 36.830’E
,
5 m
, M.V. Erdmann,
23 August 2012
.
Other material examined
:
Eviota latifasciata
- BPBM 28959
paratypes
, 10.8 &
11.7 mm
,
Gilbert Islands
= (
Kiribati
,
Tungaru
Islands); CAS 52737
paratype
,
12.6 mm
,
Gilbert Islands
; USNM 260079
paratypes
, 10.1 & 12.7,
Gilbert Islands
; CAS 226268 (4), 10.4–12.2,
Ponape
; CAS 226295, 11.5 & 12.5,
Ponape
; CAS 226296, 12.0 & 12.8,
Ponape
; CAS 226297, 9.1 & 12.1,
Ponape
.
Diagnosis
. The following combination of characters distinguishes
E. santanai
from congeners: the cephalic sensory-canal pore system lacks the IT and PITO pores, the AITO pore is not enlarged or paired, and the POP pores are small; some pectoral-fin rays are branched; the dorsal/anal formula is 8/8; and the body has six body bars with a black midcaudal peduncle spot centered on the last bar; no occipital spot; and color in life includes pinkishmauve bars that are red dorsally.
Description.
Dorsal-fin rays VI-I,8; anal-fin rays I,8; dorsal and anal soft rays branched except first, the last ray branched to base; pectoral-fin rays 16, ends of many rays broken in all
types
, but some lower rays branched; pelvic fins joined by membrane only at extreme base; no pelvic frenum; pelvic-fin membrane reduced, pelvic-fin rays I,4, 4th pelvic-fin ray with 4–7 branches, 2 segments between branches; 5th pelvic-fin ray absent; 11 branched caudal-fin rays; segmented caudal-fin rays 17; lateral scale rows 24; transverse scale rows 7; no scales on head, nape, breast, or pectoral-fin base; midline of abdomen with cycloid scales; dorsal fin triangular in shape, and the dorsal-fin spines not filamentous; cephalic sensory-pore system lacking IT and PITO pores but AITO not enlarged as in Group IV; cutaneous papilla system not discernible because specimens are in poor condition; male genital papilla non-fimbriate, smooth and straight, with a blunt tip with a few short skin flaps on the end, not reaching anal-fin base; single small female with a short papilla with a few short flaps at end (difficult to observe because of condition); body slender, front of head rounded with an angle of about 70° from the horizontal axis; mouth oblique, forming an angle of about 45° to horizontal axis of body, lower jaw not projecting; maxilla extending to center of pupil; anterior tubular nares short, just extending to upper lip and light in color; gill opening extending forward to midway between edge of preoperculum and posterior end of opercular membrane; gill membranes attached anteriorly to isthmus, without a free fold.
Measurements
(based on
holotype
and 2
paratypes
,
11.5–12.8 mm
). Head length 28.8 (28.8–29.6, 29.1); origin of first dorsal fin 37.3 (37.3–39.1, 37.9), above posterior end of pectoral-fin base; origin of second dorsal fin 57.6 (56.2–58.3, 57.4), slightly in advance of anal-fin origin; origin of anal fin 58.5 (58.5–63.3, 60.1); caudalpeduncle length 25.4 (21.3–25.4, 23.2); caudal-peduncle of moderate depth, 12.3 (11.7–13.0, 12.3); body depth slender 19.5 (19.5–21.7, 20.2); eye diameter 9.7 (9.7–10.9, 10.5); snout length 3.4 (3.4–3.9, 3.6); upper-jaw length 10.6 (10.6–12.6, 11.5).
FIGURE 1.
Color in preservative of holotype of
E. santanai
, CAS 234966, 11.8 mm. Photograph by D.W. Greenfield.
Color in preservative of
holotype
: (
Fig. 1
) Background color of head and body pale yellowish. Top of head with scattered irregular brown spots behind eyes, extending back to edge of preopercle. A few similar spots extending behind eye along top of cheek and preopercle, with a concentration towards the end of the preopercle. A small dark spot on lower portion of preopercle on left side of
holotype
(lacking in
paratypes
). Interorbital area, snout, and ventral surface of head lacking any dark pigment. Pectoral-fin base and sides of body lacking dark pigment except for a distinct black spot about half the size of the eye centered on the caudal peduncle. Pectoral and pelvic fins immaculate. Anal fin heavily pigmented, darker than other fins. Ventral half of caudal fin peppered with small dark spots with a few extending dorsally at center of fin. Distal portion of first dorsal-fin margin with small dark spots as is the second dorsal fin. Iris of eye black, pupil yellowish.
Live color
: (
Fig. 2
) Background color of head and body translucent white. Body with six internal pinkishmauve bars extending from backbone to ventral surface, the first two bars the widest, more triangular in shape, and most pronounced: first bar behind pectoral-fin base below nape and first four dorsal-fin spines; second bar below last two spines of first dorsal fin and space between the two dorsal fins; third bar below anterior half of second dorsal fin; fourth below second half of fin; fifth behind second dorsal fin; and sixth the narrowest and on the caudal peduncle with a distinct black spot on the midline. There is a crescent shaped red bar on the caudal-fin base. Each of these six internal bars have a red area over the backbone with two or three narrow red-orange bars extending up from them to the dorsal surface of body. These narrow red bars have some yellow pigment mixed with the red on the anterior half of the body. The translucent white area between these narrow dorsal bars has a very narrow vertical silvery-white line separating them. There also is a wider silvery-white bar separating the first two mauve bars ventrally. The nape is crossed by three yellow bars that are sprinkled with red. The area on top of the head and behind the eyes is bright red, with the red extending back along the backbone to under the first dorsal fin. The red also extends down onto the cheek and preoperculum. The red area on the top of the head with scattered silverywhite irregular spots that also are present on the top of the snout. Jaws with a tinge of red and area under the eye translucent white. The pupil of the eye is black and the iris red with yellow spokes radiating out from around the pupil and many small yellow spots dorsally. The operculum is yellow as is the pectoral-fin base, except that a silvery-white stripe runs across its center. Spines and rays of dorsal fins reddish.
FIGURE 2.
Underwater photograph of
E. santanai
. Photograph by M.V. Erdmann.
Distribution.
Known only from the northern coast of
Timor-Leste
.
Etymology.
The specific epithet is named in honor of Connisso Antonino ("Nino Konis") Santana, a national hero in Timor-Leste's struggle for independence who was renowned for his environmental awareness. The
type
locality of this beautiful goby species is in Tutuala, just offshore of Santana's birthplace, and moreover is located within the Nino Konis Santana National Park.
Comparisons
. In general live color pattern,
E. santanai
is most similar to
E. latifasciata
and also shares the same meristics. It does, however, differ in cephalic sensory-canal pore pattern. Whereas
E. latifasciata
belongs to Group II, only lacking the IT pore,
E
.
santanai
also lacks the PITO pore and the POP pores are very small. Other
Eviota
species that lack both the PITO and IT pores have the AITO pore enlarged or paired (Group IV), but this is not the case in
E
.
santanai
. There are only three species in Group IV that also have the same meristics as
E. santanai
:
E. shimadai
,
E. lachdeberei
, and
E. partimaculata
, but all of these have unbranched pectoral-fin rays (branched in
E
.
santanai
).
Eviota santanai
also differs from
E. latifasciata
by lacking an occipital spot and having a pigment spot behind the eye that is lacking in
E. latifasciata
(
Fig. 3
).
FIGURE 3.
Head coloration of preserved specimens, with pigmentation differences indicated by arrows. A.
Eviota santanai
holotype, CAS 234966, 11.8 mm. B.
Eviota latifasciata
paratype, USNM 260079, 12.7 mm. Photograph by D.W. Greenfield.
The
holotype
of
Eviota latifasciata
was originally described from Abaiang Atoll in the
Gilbert Islands
= (
Tungaru
Islands,
Kiribati
) with
paratypes
from both Abaiang and
Ponape
in the
Caroline Islands
(Jewett & Lachner, 1983). Non-type material was listed from
Christmas Island
in the Indian Ocean and Kapingamarangi Atoll. Since that time
E. latifasciata
has also been reported by Allen & Erdmann (2012) from “
Christmas Island
(Indian Ocean),
Indonesia
(Lesser Sunda Islands, Banda, Halmahera, and West
Papua
),
Philippines
(Palawan and Cebu),
Papua New Guinea
(Milne Bay),
Palau
,
Ponape
, and
Gilbert Islands
(
Kiribati
). ” It was also reported from the Ryukyu Islands,
Japan
by Senou
et al.
(2004), and
Tonga
by Randall,
et al.
(2003). Yet photographs of live individuals from many of these locations show considerable variation (based on photographs provided by G.R. Allen), and as discussed by Allen, Brooks & Erdmann (2013), “Live colour patterns in particular (including eye colouration) are highly diagnostic for members of this genus...”. D.F. Hoese provided color photographs of specimens from the
type
series of
E. latifasciata
from the
Gilbert Islands
, the locality of the
holotype
, (
Fig. 4
), another photograph of a specimen from the
type
locality (
Fig. 5
), and G.R. Allen provided color photographs from
Ponape
in
Micronesia
to the northeast where some
paratypes
were taken (
Fig. 6
). The color of the body bars are pinkish-mauve in
E. santanai
, whereas they are dark red in the Gilbert
Island
and
Ponape
specimens of
E. latifasciata
. The
paratypes
of
E. latifasciata
examined from the
Gilbert Islands
have a definite dark occipital spot even after having been preserved for 40 years (
Fig. 7
), as does the comparative material from
Ponape
. The specimens of
E. santanai
collected in 2012 do not have an obvious occipital spot.
FIGURE 4.
Fresh specimen from the type series of
E. latifasciata
from Abaiang Atoll, Gilbert Islands, photograph by D.F. Hoese (DFH 73-36).
FIGURE 5.
Fresh specimen of
E. latifasciata
from Abaiang Atoll, Gilbert Islands, AMS I.18048-026 (DFH 73-45), photograph by D.F. Hoese.
Recently
E. dorsimaculata
was described from the Marquesas Islands and was said to be most similar to
E. latifasciata
(Tornabene
et al.
2013)
. This species also belongs to Group II, only lacking the IT pore as does
E. latifasciata
, separating it from
E. sanatanai
. It also has a dark spot on the caudal peduncle that is above the lateral midline (centered on the midline in
E
.
santanai
).
Remarks.
The similarity of
E
.
santanai
to
E. latifasciata
presents another example of a species that is similar in color pattern to another species, but differs in the absence of a head pore. Greenfield and Randall (2010) noted that
E. toshiyuki
, known only from
Japan
, was very similar in color to
E. zonura
, known from
Australia
east to the
Mariana Islands
and
Samoa
, but differs in the absence of a head pore, and suggested that this might indicate that they were sister species. Earlier Lachner & Karnella (1980) suggested that cephalic sensory-canal pore systems might represent natural groupings of species, and continued to present new groupings in subsequent papers. These groupings have served useful in distinguishing the many different
Eviota
species from one another, particularly in dichotomous keys; however, in a recent paper Tornabene
et al.
(2013) demonstrated that pore patterns did not correlate with genetic relationships in the species they studied. Unexpectedly the correlation was with branching patterns in the pectoral-fin rays. Thus, the suspected sister species mentioned above that differed in pore patterns might actually be closely related.
FIGURE 6.
C. Underwater photograph of
E. latifasciata
, Ponape, photograph by G.R. Allen. Note parasite on abdomen.
FIGURE 7.
Color in preservative of paratype of
E. latifasciata
, BPBM 28959, 11.7 mm, Abaiang Atoll, Gilbert Islands. Photograph by D.W. Greenfield.
Both the
holotype
and
paratype
specimens were collected from similar habitats consisting of shallow, wavewashed fringing reef crest in
5-8 m
depth. Both sites were exposed to clear, relatively cool (25-27
°
C) water with reefs that quickly dropped off to over
200 m
depth. The species was moreover observed at an additional four sites along the
Timor-Leste
coastline (recorded at a total of 6 of the 20 survey sites) and is thus considered relatively common (though cryptic and shy) in the region.