Contributions to Zoology, 70 (4) 243-246 (2002)

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Short notes and reviews

Mollienesia kykesis nom. nov., a new name for petenensis Günther,

1866, and redescription, revalidation and the designation of a lectotype for

Poecilia petenensis Günther, 1866 (Teleostei: )

Fred.+N. Poeser

Institute for Biodiversity and Ecosystem Dynamics, Department of Ichthyology, Zoological Museum, Uni-

versity ofAmsterdam, P.O. Box 94766, 1090 GTAmsterdam, The Netherlands, [email protected]

Keywords: Poecilia kykesis, Poecilia petenensis, nomenclature, taxonomy

Abstract sphenops. This rendered both original names of

Gunther and as synonyms, so Rosen Bailey (1963)

Poecilia Günther, 1866 (= Mollienesia chose the petenensis gracilis Regan, name P. petenensis (although preoccu-

1913) is redescribed and is revalidated from of P. synonymy pied by the slender species) for M. petenensis in sphenops Valenciennes, 1846 and a lectotype is designated. order the to “retain at least one of names given by Mollienesia petenensis Günther, 1866 is renamed as P. kykesis the original author.” Their action, however, was to avoid homonymy with Poeciliapetenensis. nomenclaturally erroneous. Together with the res-

urrection of the slender Peten from molly synonymy

of P. this is corrected in the Introduction sphenops, error present

paper. Quite unnecessarily, Brett and Turner(1986)

renamed M. gracilis Regan, 1913 (= P. petenensis Gunther (1866) used the number of dorsal fin rays i. between Gunther, 1866) as “P. gracilis ”, e., as a means of distinction between Poecilia Bloch quo- tation marks. Re-allocating M. gracilis to Poecilia and Schneider, 1801 and Mollienesia LeSueur, 1821.

will render the slender form the name P. petenensis. This is illustrated when he described both Poecilia Instead, the sailfm Peten molly is renamed herein petenensis Gunther, 1866, a relatively large, slen- to avoid homonymy with the slender Peten molly. der short-finned molly (Fig. 2) and Mollienesia

petenensis Gunther, 1866, an equally large, but high

profile (Fig. 1). Material examined established of Regan (1913) the use the gono-

podium as a morphological criterion for generic Poecilia kykesis. Mexico, Guatemala.ZMA 121.638 (9), high- separations. His major distinction betweenPoecilia coll. de way 186, Escarcega-Villahermosa, K. Jong, l-V-1996; and Mollienesia was based on the shape of the ZMA 121.639 (8), Villahermosa-Frontera, coll. K. de Jong, 2- gonopodial tip; smooth in Poecilia', with extrusions V-1996;ZMA 121.857 (10ex. ex UMMZ 143570), Guatemala, in Hubbs Mollienesia (cf. 1926; Miller 1975). Re- Rio San Pedro de Martir, Desempeno just below El Paso de

coll, C. L. gan, therefore, allocated both species of Gunther Cabillo, Rio Usumacintasystem, Hubbs, 12-III-1935;

GCRL 6733 (10), Lake Peten, Guatemala, no further data, (1866) to Mollienesia, renaming the slender P. Poecilia petenensis'. Lake Peten,Guatemala. BMNH 1864,1. petenensis as M. gracilis. 26.377 former (lectotype by present designation, syntype ofP. Rosen and did Bailey (1963) not apply any spe- petenensis Gunther, 1866), Lake Peten, coll. Salvin, no date. cific criterion for their also consid- genera. They BMNH 1864.1.26.378-379 (4 Paralectotypes ofP.petenensis),

ered the slender and the sailfm molly from Peten same data as BMNH 1864.1.26.377;GCRL 6856 (35 ), Lake

Peten, no further data. as congeneric but placed them in Poecilia. Fur-

Rosen thermore, and Bailey synonymized 35 taxa,

including M. gracilis, into the single species P.

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Fig. la. Habitus of Poecilia kykesis nom. nov. Male (ZMA 121.855),

Fig. Ib. Habitus of Poecilia kykesis nom. nov. Female (ZMA 121.856).

and 1963: 55 Systematic section sis (Gunther, 1866); Rosen Bailey,

(pre-occupied by Poecilia petenensis Gunther, 1866)

Poecilia kykesis nom nov. Diagnosis. A = 9; D = 12-16; C = 18-22; LLS =

CPS = 20. Poecilia kykesis (Fig. 1) has no Mollienesia petenensis Gunther, 1866: 348 (Type 28-29; specific body pigmentation, for black mar- locality: Guatemala, Lake Peten); Poeciliapetenen- except

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Fig. 2. Habitus of Poecilia petenensis. Male (Lectotype, BMNH 1864.1.26.377)

In gined scales. males, these black margins can form spots, extending the rows of spots found on

the caudal fin. In addition, the dorsal fin in males

is The caudal fin spotted. exhibits a slightly pro-

duced lower margin in adult males.

The gonopodium (Fig. 3a) is similar to that in

P. unserrated petenensis (Fig. 3b) but with more

segments distally on ray 4p (modally 12 versus

modally 10-11 in P. petenensis). The gonopodium

has more or less cuboidal in segments rays 4a and

4p, which is rare, if not unique in the subgenus.

Distribution. Poecilia kykesis occurs from the

tributary of Rio Usumacinta and nearby lakes, Peten,

Guatemala to the Yucatan Peninsula, Mexico.

Etymology. “Kykesis” is Greek for “a mixing”,

reflecting the confusing mixture of homonyms,

caused by the double recognition Poecilia petenensis

and Mollienesia petenensis as congeneric species.

Poecilia petenensis Günther, 1866

Poecilia petenensis Gunther, 1866: 342-343 (Type

locality: Guatemala, Lake Peten)

Mollienesia gracilis Regan, 1913: 1012 (replace-

ment name for Poecilia petenensis Gunther, 1866);

Mollienesia sphenops gracilis; Flubbs, 1935; Poe- Fig. 3. Tips of the gonopodia(a) Poecilia kykesis. (b) Poecilia ciliagracilis ”; Brett & Turner, 1983: 128. petenensis.

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Poecilia sphenops (non Valenciennes, 1846, in part); The gonopodium of P. petenensis differs in hav-

Rosen & 1963: 52. Bailey, ing a larger number of unserrated segments termi-

nally on ray 4p (in P. mexicana modally 8-9). This

A = 8-9; D = 10-11 CPS number the number of unserrated Diagnosis. (modally 10); approaches seg-

= CS = 18 LLS = 27-30. found in the 16; (modally); Largest ments P. latipinna group: in P. kykesis

specimens examined; female: 119.0 mm SL., male: (a sympatric species of broad-finned molly, Fig.

93.0 mm SL. The sides of P. petenensis (Fig. 2) 1) this number is 12-14 (Fig. 3b).

in females than in males. are spotted, more In large Distribution. This species appears to be endemic

the females spots and a cross-hatched pigment to Lake Peten, Guatemala.

pattern on the dorsum of the body form a diamond

pattern. In smaller specimens, the diamond pat-

tern is weaker. The fins have little pigment; no Acknowledgements

spots or blotches are present. The inner jaw teeth

are unicuspid. I am grateful to Dr I.J.H. Isbrucker (ZMA) for the provided

accommodations, and for his valued while The gonopodium (Fig. 3b) is sharp, with both a suggestions preparing this manuscript. I thank Dr S.G. Poss for his loan of membranous hook at 3 and hook (GCRL) ray a spinal at the specimens under his care, and Dr O. Crimmen (BMNH) The distal 4 to 7 3 ray 5p. segments on ray are for the loan of the type specimens of P. petenensis Gunther, as well as all 4a. At unserrated, segments on ray 1866 M. I also thank (= gracilis Regan, 1913). my supervisor

the terminal 9-12 are Prof Schram ray 4p, segments unserrated, Dr F.R. for his support. Special thanks are for

Kees de who collected from several followed by 10-12 dorsally serrated segments. Ray Jong, kindly P. kykesis locations. 5a of the gonopodium has 12 unserrated terminal

segments, followed by 5 or 6 ventrally serrated

segments. Gonopodial ray 5p is unserrated. References Comparisons. Although Gunther (1866) stated

that “males are higher and shorter than females”, Brett BLH,Turner BJ. 1983. Genetic divergence in the Poecilia the males in this species are also relatively large. sphenops complex in Middle America. Bioch. Syst. Ec. 11: In his he mentionedthat the dorsal fin description, 127-137.

begins above the 11th or 12th scale of the lateral Greenfield DW. 1990. Poecilia teresae, a new species of

line. When this character was checked, it was found poeciliid fish from Belize, Central America. Copeia, 2: 449-

454. above the 10th or 11th scale.

Gunther A. 1866. A catalogue ofthe fishes in the British mu- Poecilia has more dorsal fin than petenensis rays seum. London 6: 1-368. most other species of the P. sphenops complex Hubbs CL. 1926. Studies of the fishes of the order Cyprino- (sensu Miller, 1983), modally 10 or 11 (average dontiformes VI. Misc. PubI. Mus. Zool. Michigan 16: 1-87.

9 10 in 10) versus modally or (average other Miller RR. 1975. Five new species ofMexican poeciliid fishes

It and has of the Poecilia, and species. is large a relatively slender body. genera , . Jcca. Papers Mus. Zool. Univ. Michigan. 672: 1-44. Greenfield (1990) foundthat the body of P.petenen- Miller RR. 1983. Checklist and key to the mollies of Mexico sis (= his P. “gracilis”, cf. Brett and Turner [1983]) (Pisces: Poeciliidae: Poecilia, subgenus Mollienesia). Copeia is similar to P. teresae Greenfield, 1990, but very 3: 817-822.

P. teresae had “a shorter slender and head, a more Regan CT. 1913. A revision of the cyprinodont fishes of the

Poeciliinae. Proc. Zool. Soc. London shorter caudal peduncle and a more slender body”. subfamily 1:977-1018, pi. 99-101. His data also showed that both species differed from Rosen DE, Bailey RM. 1963. The poeciliid fishes (Cyprino- P. mexicana (Greenfield, 1990: 451, table 1). An- dontiformes), their structure, zoogeography and systematics. other and is P. catemaconis large elongated species Bull. Am. Mus. Nat. Hist. 126: 1-176.

Miller, 1975, which has a tricuspid inner jaw den- tition. Received: 6 November 2001

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