A new species of Dibamus Duméril & Bibron, 1839 (Squamata: Dibamidae) from Pulau Manado Tua, Northern Sulawesi, Indonesia Author Koppetsch, Thore Author Böhme, Wolfgang Author Koch, André text Zootaxa 2019 2019-02-14 4555 3 331 345 journal article 27535 10.11646/zootaxa.4555.3.3 e655f2de-3baf-4083-bdc8-1f0f6f828a4d 1175-5326 2624448 16444F41-2D02-465F-849A-7632D522C9D9 Dibamus manadotuaensis , new species Figs. 2–7 urn:lsid:zoobank.org:act: 8817F788-72D2-4983-9DF6-CC753A829596 Holotype : MZB Lace. 14728 (ex-ZFMK 95558, Figs. 2–7 ), a male collected by N. Schneider on Pulau (= island) Manado Tua off the northern tip of the Minahassa Peninsula of Sulawesi , Indonesia , donated to the ZFMK in August 1991 . Paratypes : ZFMK 95559 ( Figs. 4B , 7B ), an adult female, and ZFMK 95560 , an adult male, with the same locality and collecting data as the holotype . Diagnosis: Dibamus manadotuaensis sp. nov. can be distinguished from all other congeners by the following combination of characters: maximum snout-vent length 135 mm ; tail length up to 14.2 mm (i.e., 1 2–13 % of SVL); labial and nasal sutures present and complete; no enlarged sublabial scale; four (three) postoculars; four to six scales on posterior edge of infralabial; 26–28 midbody scale rows; 30–33 transverse scale rows posterior to head; 25 transverse scale rows anterior to vent; 218–232 ventral scales; 39 subcaudal scales; relative size of frontal to frontonasal 0.68–0.73; relative size of interparietal to surrounding scales 0.67–1.43; 132–135 presacral vertebrae; and 21–24 postsacral vertebrae. Light bands on the body are missing ( Table 1 ). FIGURE 2. The preserved holotype of Dibamus manadotuaensis sp. nov. (MZB Lace. 14728, ex-ZFMK 95558) from Pulau (= island) Manado Tua, Northern Sulawesi, Indonesia. Photo by Morris Flecks. Description of holotype : Snout-vent length (SVL) 109 mm ; tail length (TL) 14 mm (13% of SVL); head nearly as long (HL 3.9 mm ) as wide (HW 4.0 mm); eye to snout distance (ES) 2.3 mm ; eye to nostril distance (EN) 1.8 mm ; internasal distance (IN) 1.0 mm; interorbital distance (IO) 2.4 mm ; snout bluntly rounded, distinctly conical (IN/IO ratio 0.42), projecting beyond lower jaw; nostril laterally oriented, oval, situated closer to tip of snout than to orbit (EN/ES ratio 0.78); rostral pad with a large number of evenly distributed sensory papillae; nasal sutures complete, extending from ocular to nostril; labial sutures complete, extending from anterior part of nasal suture to mouth; posterior border of rostral deeply curved; both frontonasal (FNSL/FNSW = 0.29) and frontal (FSL/FSW = 0.5) wider than long; frontonasal 1.42 times wider than frontal; frontonasal posteriorly bordered by five scales including frontal; two ocular scales; interparietal single, not enlarged, narrower than frontonasal and frontal, posteriorly bordered by four slightly smaller nuchal scales; four postoculars, with one postocular scale contacting frontal on each side; supralabial single, elongated, bordering ocular ventrally; infralabials lanceolate, separated by a smaller, trapezoid mental; six scales bordering posterior edge of infralabial; ear opening absent; eyes dimly visible through ocular; ocular scale larger than anterior body scales ( Fig. 3 ); tongue short, not bifurcated; fourteen teeth in the lower and upper jaw, respectively, each with a slightly curved tip ( Fig. 6 ). FIGURE 3. Head of the holotype of Dibamus manadotuaensis sp. nov. (MZB Lace. 14728, ex-ZFMK 95558) in dorsal (A), lateral (B) and ventral (C) views (f: frontal; fn: frontonasal; ip: interparietal; if: first infralabial; l: labial suture; m: mental; n: nasal suture; o: ocular; po: postocular; sl: supralabial). Drawings by Thore Koppetsch based on photos by André Koch. FIGURE 4. (A) Flap-like hind limbs of the male holotype of Dibamus manadotuaensis sp. nov. (MZB Lace. 14728, ex-ZFMK 95558). (B) Reduction of hind limbs in the female paratype of Dibamus manadotuaensis sp. nov. (ZFMK 95559). FIGURE 5. Skeleton structure of the male holotype of Dibamus manadotuaensis sp. nov. (MZB Lace. 14728, ex-ZFMK 95558). Body worm-like, almost cylindrical, midbody width (BW) 4.4 mm (BW/SVL ratio 0.04); head slightly distinct from neck; tail short (TL/SVL ratio 0.13), tip rounded, not bulbous, wider than rest of the tail ( Fig. 2 ); body scales smooth, subcycloid, including near preanal region; 27 midbody scale rows; 30 transverse scale rows posterior to head; 25 transverse scale rows anterior to vent; 218 ventral scales; 39 subcaudal scales; 134 presacral vertebrae; 24 postsacral vertebrae ( Fig. 5 ); tail complete; rudimentary flap-like hind limbs present, measuring 1.6 mm in length, covered with four paired scales, and terminating in a single scale with a rounded tip ( Fig. 4A ); pair of enlarged scales on preanal region, separated by a median scale, overlapping those on sides; preanal pores absent; postanal scales not reduced, compared to body scales. FIGURE 6. Skull of the holotype of Dibamus manadotuaensis sp. nov. (MZB Lace. 14728, ex-ZFMK 95558). Colouration in life: Unknown. Colouration in preservation: Dorsum dark brown to grey-brown, unpatterned ( Fig. 2 ); venter slightly paler than dorsum; scales of head and neck dark brown, each edged by a brighter border; remaining body scales, particularly on the ventral side, light brown with darker marbling; nuchal and body bands absent; tip of snout, supralabials, throat, hind limbs and preanal region slightly lighter, cream coloured ( Fig. 4A ). Variation. In the female paratype ZFMK 95559 the two flap-like hind limbs that are present in the two males, as is typical for dibamids, are lacking ( Fig. 4B ). The absence of hind limbs correlates with the reduction of osseous limb structures in the female specimen. Fibula and tibia are missing as is visible in the micro-CT images ( Fig. 7B ). In addition, this specimen shows a slightly higher number of transverse scale rows posterior to head (33 vs. 30), a lower number of scales bordering the posterior edge of the infralabial (5 vs. 6), a higher number of ventrals (232 vs. 218), and a greater snout-vent length ( 115 mm vs. 109 mm ). The male paratype ZFMK 95560 is similar to the holotype in morphology except for the missing tail probably caused by damage during collecting or by a predator. The specimen exhibits a slightly higher number of ventrals (223 vs. 218), but shows a lower number of scales bordering the posterior edge of the infralabial (4 vs. 6) and possesses only three postoculars on the right side (see Table 1 ). Comparisons. In possessing four postoculars, Dibamus manadotuaensis sp. nov. can be distinguished from the following congeners that possess three or fewer postoculars: D. alfredi Taylor 1962 , D. bogadeki Darevsky 1992 , D. booliati Das & Yaakob 2003 , D. bourreti Angel 1935 , D. celebensis , D. dalaiensis Neang et al. 2011 , D. deharvengi Ineich 1999 , D. dezwaani Das & Lim 2005 , D. floweri Quah et al. 2017 , D. greeri Darevsky 1992 , D. ingeri Das & Lim 2003 , D. kondaoensis Honda et al. 2001 , D. leucurus ( Bleeker 1860 ) , D. montanus Smith 1921 , D. nicobaricum ( Steindachner 1867 ) , D. novaeguineae Duméril & Bibron 1839 , D. smithi Greer 1985 , D. somsaki Honda et al. 1997 , D. tebal Das & Lim 2009 , D. tiomanensis Diaz et al. 2004 and D. vorisi Das & Lim 2003 . The lower maximum snout-vent length of D. manadotuaensis sp. nov. ( 135 mm ) separates it from D. seramensis Greer 1985 ( 203 mm ) and D. taylori Greer 1985 ( 169 mm ). In addition, D. manadotuaensis sp. nov. can be distinguished from D. seramensis by its lower number of mid-body scale rows (26–28 vs. 33) and the lower number of subcaudal scales of the new species ( 39 in both sexes) separates it from D. taylori (males: 41–55; females: 41–52) (see Table 2 ). FIGURE 7. Skeleton structures present in the anal region of the male holotype of Dibamus manadotuaensis sp. nov. (MZB Lace. 14728, ex-ZFMK 95558) (A) and the female paratype (ZFMK 95559) (B). TABLE 1. Measurements of the holotype (MZB Lace. 14728, ex-ZFMK 95558) and the two paratypes (ZFMK 95559, ZFMK 95560) of Dibamus manadotuaensis sp. nov. Remarks: * missing tail structures probably caused by damage during collecting. Paired characters presented in left/right order.

Dibamus manadotuaensis , sp. nov.	Holotype	Paratype	Paratype
MZB Lace. 14728, ex-ZFMK 95558	ZFMK 95559	ZFMK 95560
Sex	male	female	male
Number of postoculars	4/4	4/4	4/3
Number of scales behind supralabial	3	3	3
Number of scales on posterior edge of infralabial	6	5	4
Number of scales posterior interparietal	3	3	3
Midbody scale rows (MBSR)	27	28	26
Anterior transverse scale rows (ATSR)	25	25	25
Posterior transverse scale rows (PTSR)	30	33	32
Body width (BW) (mm)	4.4	4.6	4.7
Number of subcaudal scales	39	39	12*
Number of ventral scales	218	232	223
Relative size of frontal	0.71	0.73	0.68
Relative size of interparietal	1.2	0.67	1.43
Snout-vent length (SVL) (mm)	109	115	135
BW/SVL ratio	0.04	0.04	0.03
Tail length (TL) (mm)	14	14.2	4.8*
Relative Tail length (% of SVL)	13	12	4*
Hind limb length (mm)	1.6	–	2.7
Head length (HL) (mm)	3.9	4	4.9
Head width (HW) (mm)	4	3.5	4.5
Eye to nostril distance (EN) (mm)	1.8	2	2.1
Eye to snout distance (ES) (mm)	2.3	2.7	2.8
EN/ES ratio	0.78	0.74	0.75
Internasal distance (IN) (mm)	1	1	1
Interorbital distance (IO) (mm)	2.4	2.5	2.5
IN/IO ratio	0.42	0.4	0.4
Frontal scale width (FSW) (mm)	1.2	1.1	1.3
Frontal scale length (FSL) (mm)	0.6	0.9	0.8
FSL/FSW	0.5	0.82	0.62
Frontonasal scale width (FNSW) (mm)	1.7	1.5	1.9
Frontonasal scale length (FNSL) (mm)	0.5	0.7	0.9
FNSL/FNSW	0.29	0.47	0.47
Interparietal scale width (IPW) (mm)	0.6	0.4	1
Width of scale contacting posterior interparietal (NW) (mm)	0.5	0.6	0.7
Enlarged median sublabial	–	–	–
Presence of light band: present (+), absent (–)	–	–	–
Labial suture (LS): complete (+), incomplete (–)	+	+	+
Nasal suture (NS): complete (+), incomplete (–)	+	+	+
Rostral suture (RS): present and complete or incomplete (+), absent (–)	+	+	+
Presacral vertebrae	134	135	132
Postsacral vertebrae	24	21	7*

TABLE 2. Comparison of several scale characters and measurements of all nominal species of Dibamus (modified from Greer 1985; Diaz et al. 2004; Das & Lim 2009; Quah et al. 2017). Numbers of specimens are given in parentheses. Entries for mid-body scale rows and subcaudal scales are as follows from top to bottom: range, mean and sample size.

Species of Dibamus Number of postoculars		Number of scales on	Mid-body scale rows	Number of subcaudal scales		Relative size of Max. SVL (mm) Tail Length
posterior edge of	(% of SVL)
infralabial	Male	Female	Frontal Interparietal
manadotuaensis , sp. nov.	4(3)	4(1) 5(1) 6(1)	26–28 27 3	39 39 2	39 39 1	0.68–0.73 0.67–1.43		135	12–13
alfredi	2(4)	3(3) 4(1)	20–21 20.3 3	46–47 46.5 2	41–47 43.5 2	1.4–2.0	1.7–2.2	135	17–18
23	51
bogadeki	1(1)	2(1)	23	51	?	?	?	177	22.5
1	1
20	24–39
booliati	1(2)	4(2)	20	?	31.5	?	?	102.7	9.4–13.0
1	1
24	52+
bourreti	1(1)	2(1)	24	?	52+	2.3	4.5	151	23
1	1
celebensis	2(10) 3(3)	3(6) 4(7)	26–30 27.4 13	38–40 39.3 3	35–40 38 4	1.2–2.3	1.0–2.9	188	10–13
dalaiensis	1(4)	3(4)	20 20 4	50 50 1	48–52 49.3 3	1.4–1.5 1.4	1.3–1.8 1.5	127.6	18–22
16	57
deharvengi	1(1)	2(1)	16	57	?	1.3	1.4	92	22.4
1	1

22 dezwaani 2 4 22? 37?? 123.1 12.75 1 floweri 1(2) 4(2) 21 46 23 1.1–1.5 1.3–1.8 112 11.4–15.2

20	53	54
greeri	1(3)	1 & 3 (2)	20	53	54	?	?	86	23–28
1	1	1
20	36
ingeri	2(3)	3(1)	20	36	?	1.5	1	96	14.8
1	1

......continued on the next page TABLE 2. (Continued)

Species of Dibamus Number of postoculars		Number of scales on	Mid-body scale rows	Number of subcaudal scales		Relative size of Max. SVL (mm) Tail Length
posterior edge of	(% of SVL)
infralabial	Male	Female	Frontal	Interparietal
23	59
kondaoensis	2(1)	3(1)	23	59	?	1.03	1	112.4	19.4
1	1
leucurus	1(23)	3(21) 4(2)	20–23 21 23	48–52 49.5 2	41–47 43.5 4	1.2–4.2	1.0–3.1	136	16–20
22	49	43
montanus	1(2)	2(2)	22	49	43	2	2.2	130	15–18
2	1	1
23–25	34–38	31–36
nicobaricum	1(6)	4(6)	24.6	35.6	34.3	?	?	134.7	8.7–18.3
6	3	3
novaeguineae	2(92) 3(2)	3(53) 4(41) 5(1)	22–26 24.5 107	42–45 43 6	37–42 39.6 9	1.0–3.0	0.7–2.4	158	10–19
33	40
seramensis	4(1)	4(1)	33	?	40	0.7	1.2	203	11
1	1
smithi	1(1) 2(4)	2(5)	18-19 18.8 5	59 59 1	59–61 60 3	1.5–2.3	1.3–2.0	108	21–24
18–19	44–58	27–57
somsaki	1(4)	2(4)	18.5	51	42	1.1–1.3	1.0–2.2	106	18–24
4	2	2
taylori	3(13) 4(6)	2(2) 3(14) 4(4)	22–28 23.4 22	41–55 48.4 5	41–52 48 7	0.2–1.3	1.0–1.2	169	14–19
24	42
tebal	2	4	24	42	?	1.4	0.1	133.5	18.65
1	1
25–26	50	45–48
tiomanensis	1(3)	4(3)	25.3	50	46.5	1.2	1.8	123	15–16
3	1	2
20	33	11
vorisi	2(2)	3(2)	20	33	11	1.2	1	90.1	6.1–16.8
2	1	1

Etymology. The specific epithet manadotuaensis refers to the little volcanic island of Manado Tua, the type locality and only known distribution of the new species. Distribution. At present, Dibamus manadotuaensis sp. nov. is only known from the type locality Pulau (= island) Manado Tua, Northern Sulawesi , Indonesia , which belongs to the Bunaken Marine National Park ( Fig. 1 ). It is likely that this species also inhabits the other surrounding islands off the coast of Manado, the capital of Sulawesi Utara Province . Natural history. While nothing is known about behaviour or ecology of D. manadotuaensis sp. nov . , it seems likely that it resembles those of other dibamids from insular Southeast Asia. All known species show a fossorial lifestyle and occur in rainforest leaf litter and soil ( Das & Lim 2009 ). They feed on small arthropods and earth worms ( Zug et al. 2001 ). When disturbed a defensive, anti-predator behaviour is reported for several species, such as D. floweri and D. tiomanensis . They flare up their body scales, so that the smooth surface appears to be covered with little bristles, resembling the epidermis of possibly non-palatable earthworms ( Diaz et al. 2004 ; Quah et al. 2017 ).