Stuttgarter Beitrage zur Naturkunde Serie A (Biologie)

Herausgeber:

Staatliches Museum fiir Naturkunde, Rosenstein 1, D-70191 Stuttgart

Stuttgarter Beitr. Naturk. Nr. 633 Stuttgart, 31. 3. 2002

Centrodraco abstractum, a New Species of Deepwater Dragonets from the Philippines (Teleostei: Draconettidae)

By Ronald Fricke, Stuttgart

With 1 figure

Summary

Centrodraco abstractum n. sp. from San Bernardino Strait, Philippines is described and compared with allied species. The new species is characterized by having 3 stout spines in the first dorsal fin, 12-14 soft rays in the second dorsal fin, 13 anal fin rays, and 24-27 pectoral fin rays; the first spine of the first dorsal fin slightly longer than the second spine in both sexes, but not elongate; the second dorsal fin distally slightly convex in both sexes, the male with very short distal filaments; the sides of the body with a group of 6-7 short transverse streaks below the anterior portion of the second dorsal fin, a dark saddle each before the first dorsal fin base and behind the second dorsal fin base, and a dark area on the caudal peduncle and basal caudal fin extending as a short dorsal dark stripe on the proximal one-third of the cau- dal fin; anterior and posterior basal sections of second dorsal fin dusky in male, vertical fins otherwise pale.

A revised key to the species of the family Draconettidae is presented.

Zusammenfassung

Centrodraco abstractum n. sp. wird aus der San-Bernardino-Straße, Philippinen beschrie- ben und mit verwandten Arten verglichen. Die neue Art ist innerhalb der Gattung Centro- draco durch die folgenden Merkmale charakterisiert: 3 dicke, spitze Stacheln in der ersten Rückenflosse, 12-14 Gliederstrahlen in der zweiten Rückenflosse, 13 Afterflossenstrahlen, 24-27 Brustflossenstrahlen; erster Stachelstrahl der ersten Rückenflosse etwas länger als zweiter Strahl, aber nicht verlängert und ohne Filament; zweite Rückenflosse distal leicht konvex, beim Männchen mit sehr kurzen distalen Filamenten; Körperseiten mit einer Grup- pe von 6-7 kurzen vertikalen Streifen unterhalb des vorderen Teils der zweiten Rückenflosse; jeweils ein dunkler Sattel vor der ersten Rückenflosse und hinter der zweiten Rückenflosse; Schwanzstiel distal dunkel, mit einem dunklen Streifen, der dorsal auf das erste Drittel der Schwanzflosse hinausreicht; vorderer und hinterer Teil der zweiten Brustflosse beim Männ- chen basal dunkel; übrige vertikale Flossen ohne Zeichnung.

Ein revidierter Bestimmungsschlüssel für die Arten der Familie Draconettidae ist beigefügt.

2 STUTTGARTER BEITRÄGE ZUR NATURKUNDE Ser. A, Nr. 633

Contents Fe Doh sire fens soe Wig) Sure ee BE N ER eb te OM ey Se Pad oy A a RA NER, 2 2. Methods, materials and acknowledgements .............. 0. se eeee eee e teen nennen 2 Sie entrbArato Abstraetum Di. spa A. KP Ret Petes ret te gd Pi dd ey eee ltr a Rt sy 3 4./Key to the species of the family Draconettidae® 2... i606 coed sie ea ee een 6 SRE ks NC ee A a ER u nd 7

1. Introduction

The deepwater dragonets of the family Draconettidae are a group of benthic ma- rine fishes living on soft bottoms of the continental edges and slopes and on subma- rine ridges and seamounts, at depths of 128-600 m. Its members are distributed worldwide in tropical and subtropical oceans (between 35°N and 35°S). Most species of draconettids are considered to be extremely rare; the majority is known only from a few specimens. The rarity may be due to the scarcity of large soft bot- tom areas suitable for dredging or trawling operations, on the continental slopes which are the main habitat of draconettid species.

The first draconettid was described by JORDAN & Fow Ler (1903) from Japan (Draconetta xenica). Another species described by REGAN (1904: Draconetta acan- thopoma) was later separated from Draconetta xenica on the generic level by REGAN (1913), who described a second genus, Centrodraco. This genus was synonymized with Draconetta in the first revision of the family (BRiccs & BERRY, 1959), but later considered as valid. FRICKE (1982) compiled a list of the nominal genera and species of the family known at that time. NAKABo (1982) published another revision, con- sidering seven species as valid.

In the 1980s, the knowledge about draconettid fishes increased rapidly due to bet- ter sampling techniques and collecting efforts in remote areas. After NAKABO’s revi- sion, several unknown species were found. Parın (1982) published descriptions of three new species from the Southeast Pacific, an area from where no fishes of the family had been recorded before (Draconetta gegonipa, D. nana, D. striata); these species were later assigned to Centrodraco. The family was again revised by FRICKE (1992), who recognized a total of 11 species as valid (Draconetta xenica and 10 species of Centrodraco) including two new species and a new subspecies. Draconet- ta xenica is found at a depth range of 128-241 m, while species of Centrodraco occur deeper at 210-600 m.

During an expedition to the Philippines, J. R. Paxton of the Australian Museum (Sydney, Australia) collected two specimens of another, unknown draconettid of the genus Centrodraco which is described in the present paper. A revised key to the fam- ily Draconettidae is presented.

2. Methods, materials and acknowledgements

Methods: The measurement system follows Fricke (1983a, 1992), which is modified from Husgs & LAGLER (1958) except for the measurements starting at the tip of snout, which are measured from the mid of the upper lip, not from the tip of the upper jaw. The reason is that the upper jaw is protractile, which would lead to different measurements at different stages of jaw protraction if measuring from the tip of the jaw. If not otherwise stated, propor- tions are given as thousandths of SL. In the description, the data of the paratype follow those of the holotype, in parentheses.

The fin ray counting method follows Fricke (1983b). Spines are counted with large Roman

FRICKE, CENTRODRACO ABSTRACTUM N. SP. 3

numbers (1, I, ...), segmented branched soft rays with Arabian numbers (1, 2, ), segmented unbranched soft rays with small Roman numbers (i, 11, ...), and unsegmented unbranched soft rays with small Roman numbers in parentheses ((i), (ii), ...). Different types of fin rays which are connected by a membrane are connected by a comma (,); if they are not connected by a membrane, a plus sign is inserted (+).

The key for the identification of the genera and species of the family Draconettidae is di- chotomous. As draconettid species are highly sexually dimorphic, males and females of many species are keyed out separately in the key to genera and species. The key is thus artificial. Males of separate species may key out closer than males and females of the same species. Oth- erwise, relationships between species have been considered in the key as far as possible.

Materials: The specimens examined for the present study are deposited in the Australian Museum, Sydney, Australia (AMS).

Acknowledgements: For the permission to examine specimens in their care, I wish to thank D. F. Hose, J. M. Lets and M. MCGROUTHER (AMS, Sydney). This study has partial- ly been supported by a grant of the Deutsche Forschungsgemeinschaft, Bonn (DFG, Grant No. ER 775/17-1).

3. Centrodraco abstractum n. sp. (Fig. 1)

Material

Total: 2 specimens.

Holotype: AMS 1.36455-006, male, 96.8mm SL; Philippines, San Bernardino Strait, 12°54.49N 124°23.77’E — 12°57.50°N 124°21.45’E, 382-376 m depth; J. R. PAxTon et alii; 23 September 1995.

Fig.1 Centrodraco abstractum n. sp., AMS 1.36455-006, Philippines, San Bernardino

Strait; lateral view. - Above: Holotype, male, 96.8 mm SL; - below: paratype, female, 89.7 mm SL. - Scales: 10 mm.

4 STUTTGARTER BEITRAGE ZUR NATURKUNDE Ser. A, Nr. 633

Paratype. AMS 1.36455-000, 1 female, 89.7 mm SL; same data as the holotype.

Etymology

“Abstractus“ (Latin) means abstract; the name of the new species refers to the body colouration which reminds to pieces of abstract art style.

Diagnosis

A species of Centrodraco with 3 stout spines in the first dorsal fin, 12-14 soft rays in the second dorsal fin, 13 anal fin rays, and 24-27 pectoral fin rays; the first spine of the first dorsal fin slightly longer than the second spine in both sexes, but not elongate; the second dorsal fin distally slightly convex in both sexes, the male with very short distal filaments; the sides of the body with a group of 6-7 short transverse streaks below the anterior portion of the second dorsal fin, a dark saddle each before the first dorsal fin base and behind the second dorsal fin base, and a dark area on the caudal peduncle and basal caudal fin extending as a short dorsal dark stripe on the proximal one-third of the caudal fin; anterior and posterior basal sections of second dorsal fin dusky in male, vertical fins otherwise pale.

Description

D, III (III); D> xiii, 1 (xi, 1); A 13 (13); Py vi,16, 11, total 24 (iv—vi, 18-21, 11, total 26-27); P 1,5; C (ii), 11,8,11, (ii).

Head 264 (275). Eye 135 (133). Preorbital length 59 (49). Interorbital distance 9 (14). Maxillary length 98 (106). Opercular spine 1.78 (2.05) in subopercular spine. Body depth 152 (144). Body width 164 (170). Caudal peduncle length 112 (100). Caudal peduncle depth 60 (60).

First dorsal fin low in both sexes, first spine longer than second spine but not fil- amentous or extended, length of first spine in the male 87, 2"4 spine 81, 3'4 spine 48; in the female, length of 15! spine 87, 2"4 spine 85, 3rd spine 41. Predorsal (1) length 319 (325). Second dorsal fin distally slightly convex, fin rays simple, the last divided at its base; rays with short distal filaments in the male. First ray of second dorsal fin in the male 163, last ray 70; first ray in the female 152, last ray 41.

Predorsal (2) length 459 (466). Anal fin beginning on a vertical through 34 or 4th membrane of second dorsal fin. Anal fin rays branched, the last divided at its base. First anal fin ray in the male 63, last ray 78; 1st ray in the female 58, last ray 65. Pre- anal fin fin length 551 (566). Pectoral fin reaching back to level of 3"d anal fin ray. Pectoral fin length 246 (262). Prepectoral fin length 318 (331). Pelvic fin reaching back to level of first anal fin ray base. Pelvic fin spine 41 (55); pelvic fin length 262 (303). Prepelvic fin length 280 (258). Caudal fin distally mostly straight; caudal fin length 215 (221).

Colour in alcohol. Eye dark grey. The sides of the body with a group of 6-7 short transverse streaks below the anterior portion of the second dorsal fin, a dark saddle each before the first dorsal fin base and behind the second dorsal fin base, and a dark area on the caudal peduncle and basal caudal fin extending as a short dorsal dark stripe on the proximal one-third of the caudal fin. Anterior and posterior basal sec- tions of second dorsal fin dusky in male, vertical fins otherwise pale.

Sexual dimorphism. The male has a slightly higher second dorsal fin than the fe- male, the second dorsal fin rays with short distal filaments (lacking in the female),

FRICKE, CENTRODRACO ABSTRACTUM N. SP. 5

and the anterior and posterior basal portions of the second dorsal fin dusky (pale in the female).

Distribution

Philippines (San Bernardino Strait). Known only from the type locality, where the species was collected with an otter trawl at a depth of 376-382 m.

Relationships

This species is characterized as a member of the genus Centrodraco as it possesses stout and pungent first dorsal fin spines, and 13 anal fin rays. It is closely related to species of Centrodraco with a low second dorsal fin in males, and with the first spine of the first dorsal fin longer than the second spine, including C. gegonipus (Parin, 1982) (Parın, 1982: 558, figs 1 C-D, Sala-y-Gomez Ridge, SE Pacific, as Draconet- ta gegonipa; FRICKE, 1992: 172-174, fig. 3, revision), Centrodraco ornatus (Four- manoir & Rivaton, 1979) (FOURMANOIR & RIvaTION, 1979: 418, fig. 10, S of Ile des Pins, New Caledonia, as Draconetta ornata; FRICKE, 1992: 182-184, revision), and Centrodraco rubellus Fricke, Chave & Suzumoto in Fricke, 1992 (FRICKE, CHAVE & SUZUMOTO in FRICKE, 1992: 185-187, fig. 11, Hawaiian Islands, Oahu, Mamala Bay, 363 m depth, type locality; off SE Lombok/Indonesia). The new species differs from C. gegonipus in having a lower first spine of the first dorsal fin in the male (first spine extended in C. gegonipus), much shorter second dorsal ray filaments in the male (about half of the rays filamentous in C. gegonipus), and the body and caudal fin colouration (plain brown in C. gegonipus, with a central dark blotch on the caudal fin base). It is distinguished from C. ornatus in the much shorter first spine of the first dorsal fin of the male (elongate in C. ornatus), and the body and caudal fin colouration (C. ornatus with 2-3 rows of longitudinal wavy streaks or spots; caudal fin without dark areas or streaks). Centrodraco abstractum differs from C. rubellus in the lacking filament of the male’s first dorsal fin spine, which is longer than the second spine in the female (shorter than the second spine in C. rubellus), the pres- ence of short filaments on the male’s second dorsal fin (filaments absent in C. rubel- lus), the pale first dorsal fin (dusky to black in C. rubellus), the different body colouration (body covered with numerous rows of short vertical streaks and spots; caudal fin with a dorsal streak extending on its distal half).

Remarks

This new draconettid species brings the worldwide number of taxa of the species group up to 13, if a probably undescribed species from New South Wales/Australia (Centrodraco sp. of FRICKE, 1992) is included. Centrodraco abstractum is the first species of the genus recorded from the Philippines. In the vicinity, C. pseudoxenicus has been recorded from Hainan/China, C. nakaboi and C. ornatus from the Kyushu-Palau Ridge, and C. rubellus from Lombok/Indonesia. Any of these species may have a wider distribution range; it is at present impossible to draw zoogeo- graphical conclusions from the scarce records of the family.

6 STUTTGARTER BEITRAGE ZUR NATURKUNDE Ser. A, Nr. 633

4. Key to the species of the family Draconettidae

1 Dy, spines long and slender; D2 12; A 12; Indo-West Pacific ............. 0... eee eee ‘duh oe ston Frat te Draconetta; only species: Draconetta xenica Jordan and Fowler, 1903 — Dyspines stout and pungent; D> 14 (rarely 12-15); A 13 (-14) .......... Centrodraco, 2

2, Drrays-withlonsihlaments 2. m. 2a 25a Si Ba le SZENE 3 D; without filaments (rarely with very short filaments) ............. 0.002 eee eee eee 9

3 First dorsal fin plain black; 1st D; spine shorter than 24 spine, not filamentous; body with dark vertical lines; SE Pacific ................ Centrodraco striatus (Parin, 1982) (male) — First dorsal fin light, may be distally dark; 1st D; spine longer than 2"4 spine, filamentous; body not with dark vertical lines (may bear dark horizontal lines or dark blotches) ....4

4, “Body-with:2=3 long: horizentaldarkstreaks". . a. 2 ana nr an 5 — Body without long horizontal dark streaks (may have dark spots or blotches or short ocel- laterdarksstreaks) a ne ern 0s 6

5 Each A membrane with a dark blotch; D2 membranes each with a vertical dark line, distal- ly dark; first D; spine 147 or less (in specimens with more than 70 mm SL); first D2 ray less than 200 (in specimens with more than 70 mm SL); Western Indian Ocean .............

ee eee ee ete eee Centrodraco oregonus lineatus Fricke, 1992 (male)

— Anal fin light, without dark blotches; D2 membranes without vertical dark lines, distally dark; first D; spine 148 or more (in specimens with more than 70 mm SL); first D2 ray more than 230 (in specimens with more than 70mm SL); Central Atlantic Ocean .......

DUDEN Cert EEE Centrodraco oregonus oregonus (Briggs and Berry, 1959) (male)

6 Body with short ocellate lines and blotches; each A membrane with a dark spot; West Pa- CLL 2a A RR U NER LEE DER Centrodraco ornatus (Fourmanoır and Rivaton, 1979) (male) — Body not with ocellate lines and blotches (may have small spots); anal fin plain white ..7

7 Body densely covered with dark spots; Japan and China ............ 0... cece e eee aes PEE ea are tLe coe ane Oe Centrodraco pseudoxenicus (Kamohara, 1952) (male) — Body plain whitish or brown; if bearing spots, not densely covered, but spots in two dis-

tiliet-sroupsyor .Paciicwm Australian I nem, a frets Meg Bee Meee 8 8 Ds; membranes with vertical dark lines, distally dark; caudal fin base without a dark blotch; OLE NW AGS tt alia Mier tea N SiH) Centrodraco insolitus (McKay, 1971) (male) — Ds» membranes plain whitish, without vertical lines, may be distally dark; caudal fin base with a dark brown blotch; SE Pacific ....... Centrodraco gegonipus (Parin, 1982) (male) 9. First Dy spınesshorter than. second spine 5... 2. u» ve een « 10 First Di-spineilonger'than-seeond:spinenl 2 2.4 <u: att > AU N ee age aha et 19 10 First D, spine more than 2.5 in second spine; Australia ............... Centrodraco sp. First Drspine;less;than 18 n second: spine. a, conn aa ee een de Fre 11 PL SOG plait Clie. ra ee sees SS Den u nn en un 12 = "Dy,notplainblack (may: be distallysdarky © oo. aa an A ar are at et 13

12 Body with about 11 regular vertical dark streaks; anal fin with distal dark spots; SE Pacific ee OO ra ee Fa ara an Centrodraco striatus (Parin, 1982) (female)

— Body with irregular dark spots and blotches, not with regular vertical dark streaks; anal fin plain: whbitex-lawauan Islandsto-Indonesan „m a ma Soto sere ee ie IL, Centrodraco rubellus Fricke, Chave & Suzumoto in Fricke, 1992 (female)

13“Body with: 2-3; long horizontalidark Iimess rasante ts 14 — Body with irregular dark blotches, without horizontal dark lines .................. 15

14 Each A membrane with a dark blotch; D; membranes each with a vertical dark line; We- stern Indian Ocean +... 2... ne ot Centrodraco oregonus lineatus Fricke, 1992 (female) — Anal fin light, without dark blotches; Dz without vertical dark lines; Central Atlantic Gleean wearin Gan arse rae Centrodraco oregonus oregonus (Briggs and Berry, 1959) (female)

15 Anal fin distally blackish; caudal fin distally blackish; Pacific Ocean .................. ie ee See ae en SEE Br Centrodraco nakaboi Fricke, 1992 (males)

FRICKE, CENTRODRACO ABSTRACTUM N. SP. vi

— Anal fin whitish, without any dark; caudal fin whitish, without any dark ........... 16

16 Second dorsaltin.distally darks wt Bra ie as ce Re eee oe a sy ee me 17 — Second dorsal fin whitish, without any dark; Atlantic Ocean .......... 0. ee eee Te De ne eee ee eee Centrodraco acanthopoma (Regan, 1904) (female)

17% First dorsal-tun distally dark 29 392 8 E Savage Saban ane Repent nd 18 — ‘First dorsal fin whitish, withoutany dark; Pacific Ocean .. 04.23.00 se2 ek ew a pues Betas te ce OT ee ne RNR TD eel, as Centrodraco nakaboi Fricke, 1992 (female)

18 Caudal fin plain whitish, occasionally with a basal dark blotch; Atlantic Ocean ......... RB See nae BETT Mes ee AER Dae, Centrodraco acanthopoma (Regan, 1904) (male) — Caudal fin with a distal dark stripe and with a basal dark blotch; Pacific Ocean ......... Pa ee Se, Peet: Re: aha Moe En ded ier Pen ae Centrodraco nakaboi Fricke, 1992 (male)

19 First D; spine bearing a filament; upper third of caudal fin with a long dark streak reaching distal half of fin; Hawaiian Islands and Indonesia ........... 000s esse ceeceececeeces

pis Saati Pepa bee Centrodraco rubellus Fricke, Chave & Suzumoto in Fricke, 1992 (male)

— First D, not filamentous; upper part of caudal fin without a dark streak or with a short dark streak at most in proximal one-third of fin (caudal fin may have a basal dark blotch) cate Sy ck teach Brae at anton nck Ream ata Peat acta nals Strap Seto nA te ae tarde ana ong A gl dire eh tae wow ee od 20

20 Body densely covered with numerous round dark spots; Japan and China ............. Re Ce 0 en ned eee Centrodraco pseudoxenicus (Kamohara, 1952) (female)

— Body colouration not as described above; either plain brown or whitish, or with short lon- gitudinal streaks in its dorsal part, or with groups of short transverse streaks, or with pale brownsspotsintwordistinetetoups Wit. 6. fet ae 21

21 Body with short ocellate longitudinal streaks; West Pacific ........ 0... eee eee eee eee ec Pray rer ann, Centrodraco ornatus (Fourmanoir and Rivaton, 1979) (female)

— Body colouration not as described above; either plain brown or whitish, or with groups of short transverse streaks, or with pale brown spots in two distinct groups ........... 22

22 Caudal fin pale, without any dark; body usually with pale brown spots in two distinct SEOUDSF OLE N Wee ustraliansr tea. Centrodraco insolitus (McKay, 1971) (female) — Caudal fin with a basal dark blotch; body plain brown or with groups of short longitudi- haltransverse.streaks LC CITC ene A Lent NE AG ethers WER 23

23 Body light, with a group of short transverse streaks under anterior half of second dorsal fin; dorsal part of caudal fin with a short dark streak; male with tips of second dorsal fin filamentous only, female without filaments; Philippines .. Centrodraco abstractum n. sp.

— Body plain brown; dorsal part of caudal fin pale; distal half of second dorsal fin rays fila- Mentous:,SE-Pacitiegz Belt ee, Centrodraco gegonipus (Parin, 1982) (female).

5. References

Brıisss, J. C. & F. H. Berry (1959): The Draconettidae - a review of the family with descrip- tion of a new species. — Copeia, 1959 (2): 123-133.

FOURMANORR, P. &. J. Rıvaron (1979): Poissons de la pente récifale externe de Nouvelle- Calédonie et des Nouvelles-Hebrides. — Cahiers de |’Indo-Pacifique, 1 (4): 405-443; Paris.

Fricke, R. (1982): Nominal genera and species of dragonets (Teleostei: Callionymidae, Dra- conettidae). — Annali del Museo civico di storia naturale Giacomo Doria, 84: 53-92; Genova.

— (1983a): Revision of the Indo-Pacific genera and species of the dragonet family Cal- lionymidae (Teleostei). — X + 774 pp.; Braunschweig (J. Cramer).

— (1983b): A method of counting caudal fin rays of acanthopterygian fishes. -— Braun- schweiger Naturkundliche Schriften, 1 (4): 729-733; Braunschweig.

— (1992): Revision of the family Draconettidae (Teleostei), with descriptions of two new species and a new subspecies. — Journal of Natural History, 26: 165-195; London.

Hupps, C. L. & K.F. LAGLER (1958): Fishes of the Great Lakes region. — Bulletin of the Cran- brook Institution of Sciences, 26: I-IX + 1-213, pls 1-44; Bloomfield Hills.

8 STUTTGARTER BEITRAGE ZUR NATURKUNDE Ser. A, Nr. 633

Jorpan, D.S. & H. W. FowLer (1903): A review of the dragonets (Callionymidae) and rela- ted fishes of the waters of Japan. — Proceedings of the United States National Museum, 25 (1305) (for 1902): 939-959; Washington D. C.

Nakao, T. (1982): Revision of the family Draconettidae. - Japanese Journal of Ichthyology, 28 (4): 355-367; Tokyo.

Parın, N. V. (1982): New species of the genus Draconetta and a key for the family Draco- nettidae (Osteichthyes) [in Russian]. - Zoologicheskii Zhurnal, 61 (4): 554-563; Mosk- va.

REGAN, C. T. (1904): On the affinities of the genus Draconetta, with description of a new spe- cies. — Annals and Magazine of Natural History (7), 14 : 130-131; London.

— (1913): The classification of percoid fishes. - Annals and Magazine of Natural History (8) 12 : 111-145; London.

Author’s address:

Dr. RONALD Fricke, Staatliches Museum für Naturkunde (Museum Schloss Rosenstein), Rosenstein 1, D-70191 Stuttgart, Federal Republic of Germany; e-mail: fricke.smns@naturkundemuseum-bw.de.

ISSN 0341-0145

Schriftleitung: Dr. Wolfgang Seeger, Rosenstein 1, D-70191 Stuttgart Gesamtherstellung: Gulde-Druck GmbH, D-72072 Tübingen