Platax 14: 82-88 2017

A new record fish genus and species, Grammonus
robustus Smith & Radcliffe 1913, from southern Taiwan(Bythitidae: Bythitinae)
Hsuan-Ching Ho1,2* and Timo Moritz3,41

National Museum of Marine Biology & Aquarium, Pingtung, Taiwan

2

Institute of Marine Biology, National Dong Hwa University, Pingtung, Taiwan

3

Deutsches Meeresmuseum, Stralsund, Germany

4

Friedrich Schiller University Jena, Institut für Spezielle Zoologie, Jena, Germany*Corresponding author. E-mail:hohc@nmmba.gov.tw

Abstract
A specimen of Grammonus robustus Smith & Radcliffe, 1913 is reportedfor the first time in Taiwan. Although being widespread in the Indo-west
Pacific Ocean, the genus and species had never been found from Taiwan.
Detailed description and fresh color photo are provided.
Key words: Pisces, Taxonomy, Grammonus robustus, new record, Taiwan

Introduction

across 53 genera, but recent investigations
restricted Bythitidae as supported as
monophyletic group based on molecular
data. This study accounts 116 species in
32 genera for the family (Møller et al.,2016). In Taiwan, 9 species in 8 genera of
the family have been recorded so far (Lee& Ho, 2016; Shao, 2017), of which
Cataetyx lepidogenys (Smith & Radcliffe)
was recorded just recently by Lee & Ho
(2016). Seven of these species have beenfound in the southern Taiwan, thus theMembers of Bythitidae inhabit ahuge variety of marine habitats, fromshallow waters to the deep sea. Although
they exhibit their greatest diversity in thedeep-sea, some species even occur inwarm tropical reefs. They feed on small
fishes or invertebrates. A conspicuous
character of the family is their viviparous
reproduction mode, which is basis fortheir vernacular name: viviparous brotulas.
Nelson et al. (2016) reported 211 species

82Platax 14: 82-88 2017

northern extension of the South ChineseSea.
A male specimen of the viviparous
brotulas family Bythitidae was collectedfrom off Dong-gang fishing port,southwestern Taiwan recently. The fish
has a single short ray per pelvic fin, shortpectoral-fin radials, no teeth on palatine
and its posterior portion of maxilla well
expanded. These characters show that thespecimen belongs to the genus
Grammonus.
The genus Grammonus comprises 11valid species (Møller et al., 2016)
distributed worldwide. Of these species, G.
robustus Smith & Radcliffe, G. minutus
Nielsen & Prokofiev, G. thielei Nielsen &Cohen, and G. yunokawai Nielsen, were
distributed in adjacent countries of Taiwan.
Kannan et al. (2014) included Taiwan
within the distribution range of G.
robustus, but they did not state on whichdata they draw their occurrence map. Alsoin FishBase (Froese & Pauli, 2017)“Taiwan” is given as country in which G.
robustus is found. The cited vouchers,
however, are only deposited in acollection in Taiwan, but originated fromthe Philippines. Thus, there is currently noevidence that the genus Grammonus has
been recorded in Taiwan.
Morphological characters show thatthe herein recorded specimen belongs to
the G. robustus. From G. minutus and G.
thielei in the area it can be distinguishedby the much higher amount of dorsal fin

rays (82–89 [89 in the present specimen]
vs. less than 76), and from G. yunokawai it
differs in a higher number of totalvertebrae (44–47 [46] vs. 41) (Nielsen,2007; Nielsen & Prokoviev, 2010).
Herein, we formally document thespecies G. robustus based on the single
specimen collected from Taiwan. A
detailed description is provided below.
Materials and Methods
Methods for taking measurements
and counts followed Nielsen & Cohen(2004).
Specimen is deposited at PiscesCollection, National Museum of Marine
Biology & Aquarium, Pingtung, Taiwan(NMMB-P).

Results
Family Bythitidae
Genus Grammonus Gill, 1896
Grammonus robustus SmithRadcliffe, 1913
Figures 1-2; Table 1andGrammonus robustus Smith and Radcliffe,
1913:168, pl. 13, fig. 4 (Type locality:between
CebuandLeyte,Philippines). Nielsen et al., 1999:104.
Nielsen & Cohen, 2004:85. Nielsen,
2007:375. Randall & Hughes,
2008:143. Nielsen & Prokofiev,2010:192.
Mølleretal.,
2016:Appendix A.
Specimen examined. NMMB-P26419,
148.6 mm standard length, off Dong-gang

83Platax 14: 82-88 2017

fishing port, Pingtung, Southern Taiwan,
South China Sea, ca. 300 m depth, 20June 2017, coll. T. Moritz, P. Warth, M.
Mertzen, P. Richter and C. Marin.
Description of NMMB-P26419.
Dorsal-fin rays 89; anal-fin rays 64;
pectoral fin rays 26 or 27; caudal fin rays
8; precaudal vertebrae 12; caudal
vertebrae 34; total vertebrae 46; pelvic fin
with 1 an individual ray; 3 well-developed
toothed rakers and 15 small toothed
patches on first gill arch, 6 on upper limb,
and 9 on lower limb. Scale rows inlongitudinal series from upper gill slit tocaudal fin base about 82.
Body short, anterior half rather stout
and gradually compressed posteriorly,
gradually tapering from the anal fin into a
pointed caudal fin. Dorsal fin originating
behind pectoral fin base and anal fin
originating behind mid-body; both withlong, continuous base and connected tocaudal fin posteriorly. Origin of dorsal fin
slightly behind origin of pectoral fin.
Pectoral fin moderately long (29.7% SL),with a broad base, vertical height of thebase about half of the fin length. Pelvic
fin long (26.0% SL), with a single longsimple ray, closed to each other. Origin of
anal fin at about middle of lower marginof entire length. Lateral line interrupted at
mid-body, anterior lateral line at upperthird of anterior half of body and posterior
one at axis of posterior half of bodyrespectively.
Head moderately large (28.6% SL),rather plump, with occiput swollen. Eyesmall, covered by a circular membrane
connected to nearby skin, its diameter
14.4% of head length (HL). Snout short(29.4% HL), very broad and blunt.
Interorbital space broad (29.4% HL).
Mouth large and oblique; lower jaw
entirely included under the upper jaw.

Fig. 1. Freshly caught specimen of Grammonus robustus Smith and Radcliffe, 1913,
NMMB-P26419, 148.6 mm SL84

Platax 14: 82-88 2017

Posterior portion of maxilla well
expended, it rear margin extending forabout one eye diameter beyond verticalfrom posterior margin of eye. Two large
nostrils, anterior nostril with low irregularrim, close to upper lip, posterior nostril
just in front of the eye, a simple oval pore.
Dorsal surface of snout and interorbital
space with many small cirri or papillae.
Postorbital space about 2/3 of HL.

A.

B.

C.

Fig. 2. Grammonus robustus Smith and Radcliffe, 1913, NMMB-P26419. A. Lateralview of head showing the head pore system and naked bare area (grayshading). Arrows point to the anterior-most pores in the supraorbital (above)and mandibular (below) regions. B. Lateral view of copulatory organ. C.
Ventral view of copulatory organ.

85Platax 14: 82-88 2017

uniformly blackish with head and all finsdarker, except for the scaled regions

Posterior margin of opercle smooth,with a stout but strong spine at upperportion. A prominent skin flap bearing
large pore above opercle. Margins ofpreopercle and subopercle smooth, except
for a low, triangular spine at
approximately
middleportionofpreopercle. Isthmus membrane partly freefrom gular region. Head pores large insize, with 6 pores on suborbital region
along upper jaw, 2 pores on each side ofinternasal space close to the anterior
nostril, 4 pores on mandibular, and 3 large
pores on preopercle (Fig. 2A).
Cycloid scales cover on head andbody. Scales on head extend to a line
slightly behind posterior margin of eye,the rest of head is devoid of scales. About
10 scale rows in series from the origin of
dorsal fin to lateral line and 14 scale rows

which are slightly paler. When preserved,color slightly lighter (Fig. 1).
Distribution. Western Pacific from
Australia (Bray, 2017) to Philippines(Radcliffe, 1913; Shao, 2017), Taiwan(present study), and Japan (e.g., Araga &Tanase, 1966). Also recorded in the Indian
Ocean between India and Sri Lanka(Kanan et al., 2014), as well as in the Red
Sea and Gulf of Aden (Klausewitz &Uiblein, 1994). Possible records fromSouth Africa, though these need
confirmation (Nielsen, 1999).
Remarks.
Themeristicandmorphometric characteristics of theTaiwanese G. robustus specimen fall
mostly within the ranges provided byNielsen (2007) (Table 1), except for somedifferences. There are 26 or 27
pectoral-fin rays in our specimen, versus
only 24 or 25 rays in Nielsen (2007). The
majority of the species in the genus
Grammonus possess 23–25 pectoral-finrays, except for G. ater (18-19), G. thielei

from the origin of anal fin to the lateralline.
Teeth villiform, forming narrow
bands on jaws and vomer, absent frompalatines.
Male with copulatory organ not(21), and G. waikiki (25 or 26; Nielson &Prokofiev, 2010). The slightly higher

covered by a protective hood and lacking
ossified parts. Penis merged into a fleshy
hood in front of anal fin. A pair ofcartilaginous bumps at the anterior base ofpenis connected by a membrane andforming an anterior wall (Fig. 2B). Anal
opening small and located at front base of
the copulatory organ (Fig. 2C).

pectoral-fin ray count in our specimen
could simply represent individualvariation. The pectoral-fin length, eyediameter and interorbital width are allslightly above the highest values noted byNielsen (2007); this may also be attributed
variation between individuals.

Coloration. When freshly caught,

86Platax 14: 82-88 2017

Nelson, J. S., T. C. Grande & M. V. H. Wilson.
2016. Fishes of the World. Fifth edition.
John Wiley & Sons, New Jersey, USA.
Nielsen, J. G. 1999. In: Nelsen, J. G., D. M.
Chen, D. F. Markle & C. R. Robins (eds)
Ophidiiform fishes of the world (OrderOphidiiformes). An annotated andillustrated catalogue of pearlfishes,cusk-eels, brotulas and other ophidiiform
fishes known to date. Food Agriculture
Organization of the United Nations,125(18):94-101. Rome: FAO.
Nielsen, J. G. 2007. Grammonus yunokawai(Ophidiiformes: Bythitidae), a new
marine cavefish from the Ryukyu Islands.
Ichthyological Research, 54:374-379.
Nielsen, J. G. & A. M. Prokofiev. 2010. A new,dwarf species of Grammonus (Teleostei:Bythitidae)
foundoff
Vietnam.
Ichthyologocal Research, 57:189-192.
Radcliffe, L. 1913. Descriptions of seven new
genera and thirty-one new species offishes from the families Brotulidae andCarapidae from the Philippine Islands andthe Dutch East Indies. Proceedings of theUnitedStatesNationalMuseum,
44:135-176.
Randall, J. E. & M. J. Hughes. 2008.
Grammonus nagaredai, a new viviparous
marine fish (Ophidiiformes: Bythitidae)
from the Hawaiian Islands. PacificScience, 63(1):137-146.
Shao, K.-T. 2017. The Fish Database of Taiwan.
http://fishdb.sinica.edu.tw/eng/home.php
Smith, H. M. & L. Radcliffe. 1913. In: L.
Radcliffe. Descriptions of seven new
genera and thirty-one new species offishes of the families Brotulidae andCarapidae from the Philippine Islandsand the Dutch East Indies. Scientificresults of the Philippine cruise of thefisheries steamer "Albatross," 1907-1910.
No. 24. Proceedings of the United States
National Museum, 44(1948):135-176, Pls.
7-17.

Acknowledgements
We thank J.-T. Lin and H.-J. Chang
for curatorial assistance, and M. Mertzen,
P. Richter, P. Warth, and C. Marin forassistance in scanning, sorting, andidentifying by-catch fish. This study wassupported by the National Museum ofMarine Biology and Aquarium.

References
Araga, C. & H. Tanase. 1966. Fish stranding
caused by a typhoon in the vicinity ofSeto. Publications of the Seto Marine
Biological Laboratory, 14:155-160.
Bray, D.J. 2017. Grammonus robustus
inFishesofAustralia.
http://fishesofaustralia.net.au/home/speci
es/1755.
Froese, R. & D. Pauly. 2017. FishBase.
www.fishbase.org (version 06/2017).
Lee, C.-L. & H.-C. Ho. 2016. A new record ofCataetyx lepidogenys (Smith & Radcliffe,1913) (Bythitidae: Bythitinae) from
Taiwan. Platax, 13:1-7.
Kannan, K., L. Ranjith, S. John & K. K. Joshi.
2014. First record of Grammonus
robustus (Ophidiiformes. Bythitidae)
from Indian waters. Marine Biodiversity
Records, 7:e57.
Klausewitz, W. & F. Uiblein. 1994.
Tiefenwasser- und Tiefseefische aus dem
Roten Meer. XVII. Oligopus robustus, anew record for the Red Sea, withcomparative studies on specimens fromthe Gulf of Aden (Pisces: Ophidiiformes:Bythitidae). Sengenbergiana Maritima,
25:21-28.
Møller, P. R., S. W. Knudsen, W. Schwarzhans& J. G. Nielsen. 2016. A newclassification of viviparous brotulas(Bythitidae), with family status for
Dinematichthyidae based on molecular,morphological and fossil data. MolecularPhylogenetics
andEvolution,
100:391-408.

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Platax 14: 82-88 2017

Table 1. Meristic and morphometric data of Grammonus robustus Smith and Radcliffe,
1913.

NMMB-P26419

Japan and thePhilippines
Nielsen (2007)148.6

105-207 (n=13)

Dorsal fin rays

89

82–89

Anal-fin rays

64

59–65

Abdominal vertebrae

12

12–13

Caudal vertebrae

34–Total vertebrae

46

45–47

Pectoral-fin rays

26;27

24–25

Caudal-fin rays

88

Long rakers on anterior gill arch

33

Total rakers

18

15–20

Anterior dorsal fin rays above vertebral number

7

6–7

Anterior anal fin rays below dorsal fin ray number

3129–34

Anterior anal fin rays below vertebral number

18

17–19

Morphometrics% SL

Head length

28.6

27.0–29.0

Body depth at head

28.4

24.5–29.0

Predorsal length

32.2

32.0–34.5

Preanal length

54.6

55.0–59.0

Pectoral-fin length

19.9

17.0–19.0

Pelvic-fin length

12.1

11.0–16.5

Dorsal-fin base

71.1

–

Anal-fin base

43.5

–Eye diameter

4.1

3.2–3.8

Interorbital width

8.4

6.9–7.3

Snout length

6.4–Upper- jaw length

16.4

14.5–16.5

Height of posterior margin of maxilla

6.5

5.3–6.8

TaiwanStandard length (mm)Meristics

88