UvA-DARE (Digital Academic Repository)

From the Amazonriver to the Amazon molly and back again

Poeser, F.N.

Publication date 2003

Link to publication

Citation for published version (APA): Poeser, F. N. (2003). From the Amazonriver to the Amazon molly and back again. IBED, Universiteit van Amsterdam.

General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons).

Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible.

UvA-DARE is a service provided by the library of the University of Amsterdam (https://dare.uva.nl)

Download date:24 Sep 2021 From the Amazon river to the Amazon molly and back again: Introduction iii

Pre-Hennigian taxonomy of Poecilia

In this introduction, I summarize the taxonomy of Poecilia and its allies. This is done in two chronological arranged sections. A third section is moved to Appendix 1. In Appendix 1, I summarize the taxa recorded by Eschmeyer (1990) as former and present synonyms of Poecilia in alphabetic order. This list is annotated and some taxa are added to provide an overview of relevant the taxa. The pre-Hennigian taxonomie history of Poecilia originates from the description of P. vivipara to culminate in the revision of Rosen and Bailey (1963) and its direct consequences. The revision of Rosen and Bailey is considered the standard of present day poeciliid taxonomy (cf. Parenti and Rauchenberger, 1989), also for Poecilia. Within Poecilia, there is a large species complex of morphological similar taxa that is referred to as the P. sphenops complex. The species of this group (Schultz and Miller, 1971; Menzel and Darnell, 1973, Miller, 1975, 1983, 1994; Poeser, 1992, 1995, 1998, 2002a, in press) have been considered as variations of one single, widely dispersed species, viz., P. sphenops (cf. Garman, 1895; Regan, 1908, 1913; Hubbs, 1926a; Rosen and Bailey, 1963). A great deal of my own work has concentrated on characterizing the P. sphenops complex. Besides the P. sphenops species group, commonly referred to as the "mollies", there are the "guppies", i.e., P. reticulata and similar species. The taxonomie details are beyond the scope of this introduction, it is treated in detail in Chapter 11; here it suffices to mention that the taxonomy of Poecilia stretches beyond "mollies and guppies." The taxonomie history is divided into two parts, comprising the 19th and 20th century respectively, based on prevailing taxonomical insights. Whereas the taxonomists in the 19th century were primary concerned about general appearance, fin ray counts, dental structures and intestines, the 20th century taxonomists mainly focussed on the structures in the modified anal fin in the male, i.e., the gonopodium. The latter approach led to a multiplicity of taxa, in which every gonopodial ray represented information for accepting or rejecting genera. For example, after assessing Regan's (1913) illustration of the gonopodium of P. vivipara (Fig. 6C), Hubbs (1924a) described Neopoecilia holacanthus, providing a much more detailed illustration (Fig. 7A). However, after examining material of P. vivipara, Hubbs (1926a) realized he had pictured the same species, only with a greater accuracy. The revision of Rosen and Bailey (1963), in which the gonopodia had very little influence on infrageneric classification, resulted in serious lumping. The taxonomy subsequent to Rosen and Bailey is characterized by attempts to find a balance between splitting and lumping.

19th Century taxonomy Bloch and Schneider (1801) The genus Poecilia Bloch and Schneider, 1801 was described as a group of five species, viz., P. vivipara from Surinam, P. coenicola from Carolina (USA), P.fasciata and P. majalis from New York (USA), and P.fusca from 'Pacific Islands'. Poecilia vivipara was figured iv From the Amazon river to the Amazon molly and back again: Introduction

with a forked tail (Fig. 1A), together with an opened body to give evidence of its viviparity (Fig. IB). Specific details from its description were (translated from Latin; B. = gill rakers, P. = pelvic fin rays, V. = ventral fin rays, A. = anal fin rays, C. = caudal fin rays, D. = dorsal fin rays): "compressed body, head with scales, depressed on top, broad, mouth blunt, lateral line near to back, broad caudal fin, split, anus near head. B. 6, P. 12, V. 6, A. 7, C. 20, D. 7."

Figure 1 (after Bloch and Schneider, 1801). A. Holotype of Poecilia vivipara B. Holotype ventrally opened to show developing eggs

LeSueur(1821) Mollienesia latipinna LeSueur, 1821, from which the vernacular name 'molly' originated, was described before the position and modifications of the anal fin were recognized as sexual dimorphic characters (Fig. 2A). Mollienesia differed from another form LeSueur recognized, viz., Poecilia multilineata LeSueur, 1821, mainly in the relative position of the anal fin. Subsequent to the recognition of sexual dimorphism in poeciliid fishes, the latter taxon (Fig. 2B) proved to be the female sex of M. latipinna.

Muller and Troschel (1844) In the 19th century several nominal taxa were subsequently described, in which the males were assigned to new genera and the females were recognized as Poecilia. For example, from collections of live-bearing fish sent from Mexico, the females (referred to as "genus Poecilia") were sent to Dr. Valenciennes (see below), whereas a male was described as Molinesia (sic) fasciata Muller and Troschel, 1844. The holotype of M.fasciata was switched From the Amazon river to the Amazon molly and back again: Introduction v

with the holotype of M. surinamensis Muller and Troschel, 1844 (cf. Paepke and Meyer, 1995), also a male specimen. Both M.fasciata and M. surinamensis (both males) had specific names that were pre-occupied by a species in Poecilia, respectively P. fasciata and P. surinamensis (both supposedly females). In this particular (and peculiar) case, the authors seem to have willingly transferred two species of Poecilia to Mollienesia after the other gender was discovered {Mollienesia is from Mars, Poecilia is from Venus). However, since Muller and Troschel's (1844) account is very sketchy, we will forever guess their reasons.

Figure 2 (after LeSueur, 1821). A. Holotype of Mollienesia latipinna B. Holotype of Poecilia multiline-ata

Rosen and Bailey (1963) wrote: "Molinesia fasciata Muller and Troschel, 1844, when referred to Poecilia by Eigenmann (1893, p. 57), became a junior secondary homonym of Poecilia fasciata Bloch and Schneider, a synonym of Fundulus heteroclitus (Linnaeus). Had this homonymy been noted and Molinesia fasciata Muller and Troschel rejected prior to 1960, that name would now be unavailable ... Because apparently no such action was taken, we vi From the Amazon river to the Amazon molly and back again: Introduction

assume that the name is nomenclaturally available ... however, the original description is so sketchy ... We therefore regard Molinesia fasciata as unidentifiable unless the type material be located."

Figure 3 (after Cuvier and Valenciennes, 1846). Holotype of Poecilia sphenops

The type material of both Muller and Troschel's species was located and excellently redescribed by Paepke and Meyer (1995). In an account of historical documents deposited at the archives of the Berlin Museum, they recorded the collection site where a Mr. Deppe collected live-bearing fish (referred to as "genus Poecilia") from rivers in the Central Veracruz State (Rio Misantla at Misantla and Rio Tacoluta [Rio Tecolutla], see Paepke and Meyer, 1995). At about the same time Mr. Deppe collected his material in Mexico, a Mr. Steglich collected live-bearers in Surinam, which he sent to Berlin. In their discussion, Paepke and Meyer related to more mix-ups of Deppe's material, and concluded that the holotype of Molinesia fasciata must have been switched with the holotype of M. surinamensis. They illustrated and accurately described both holotypes, showing that the fish registered as "ZMB 3472, holotype of Molinesia fasciata" is indeed a specimen of P. vivipara. Also the specimen in ZMB 3473, "Molinesia surinamensis," is without doubt the same as P. sphenops (inferred from meristic evidence, dental structures and type locality Veracruz). Paepke and Meyer (1995) derived no nomenclatural consequences from this mix-up. Molinesia fasciata was assigned to the synonymy of P. vivipara, and M. surinamensis, assigned to the synonymy of P. sphenops, would become P. surinamensis, a junior homonym of P. surinamensis Humboldt and Valenciennes, 1821. In the latter case, the name P. sphenops is also retained. I disagree with this latter conclusion. Allocation of P. surinamensis to the synonymy of P. sphenops would imply the occurrence of P. sphenops in Surinam, which is an incorrect notion (as is the occurrence of P. vivipara in the Veracruz district, see Chapter 11). The mistake made by switching the holotypes of these species cannot replace the range of both species, as currently known to science. I therefore propose to recognize the exchange of holotypes and acknowledge the original description of M. fasciata (and of M. surinamensis) as valid. From the Amazon river to the Amazon molly and back again: Introduction vii

Molinesia surinamensis remains a synonym of P. vivipara, whereas M. fasciata has priority over P. sphenops (as noted by Rosen and Bailey, 1963). Generic allocation to Poecilia would render its name as P. fasciata (Muller and Troschel, 1844), which is, however, pre-occupied by a synonym of Fundulus heteroclitus (Linnaeus, 1766).

Valenciennes (in: Cuvier and Valenciennes, 1846) Valenciennes revised the ill-defined genus Poecilia (from: poikilios, which is Greek for variegated or multicolored; cf. Cuvier and Valenciennes, 1846) which united several non- related multicolored species (cf. Bloch and Schneider, 1801). Poecilia vivipara was not examined by Valenciennes, whereas P. coenicola and P. fasciata were considered conspecific (but were apparently not allocated to any taxon), and P. majalis was transferred to another (not further described) genus. Poecilia fusca was recognized as synonymous with Eleotris nigra Cuvier and Valenciennes, 1846. Valenciennes also disputed the allocation of P. vivipara. He recognized P. surinamensis Valenciennes, 1821, P. schneideri Valenciennes, 1821 and P. unimaculata Valenciennes, 1821 as a valid species (for the designation of author names, see Lazara, 1993), whereas Valenciennes suggested to rename P. vivipara to P. schneideri, because he was convinced that all members of 'his' Poecilia were viviparous. Valenciennes' Poecilia was further distinguished by the structure of the jaws and accompanying teeth, and by their long and simple intestines. Valenciennes began his species list with an elaborate account of differences between P. surinamensis and P. vivipara. He also reported how P. surinamensis was transported to Martinique for mosquito control on this French governed islands of the Lesser Antilles. Poecilia unimaculata, the second species in Valenciennes' list, seemed to resemble P. surinamensis very much. The third species, P. sphenops Valenciennes 1846, differed markedly from the previous two species by its sharp mouth and in meristic characteristics (Fig. 3). It had nine dorsal fin rays, eight anal fin rays, 29 caudal fin rays, 14 pectoral fin rays, and 6 ventral fin rays. In the description, Valenciennes mentioned that he received several specimens of this new species from other collections (from Vera Crux (sic), without mentioning the collector [but see above]). Poecilia dominicensis Valenciennes, 1846, the fourth species in Valenciennes' list, was later allocated to Limia Poey, 1854, whereas P. punctata Valenciennes, 1846 (5th species) and P. gracilis Valenciennes, 1846 (6th species) were also transferred to different genera by subsequent authors (see Appendix 1). After discussing P. multilineata LeSeuer, 1821, the eight and final species in his list is P. schneideri, which Valenciennes considered to be possibly the same species as P. vivipara. After mentioning some earlier descriptions of viviparous fish (including the examination of the circulatory system in unborn young!), Valenciennes was convinced that all species of his Poecilia were viviparous, making the name P. vivipara unnecessary. As a result, viii From the Amazon river to the Amazon molly and back again: Introduction

Valenciennes' list did not contain a single species from the original list of Bloch and Schneider (1801). Mollienesia LeSueur, 1821 was still recognized as a separate genus, again accentuating the differences found in the anal fins. Valenciennes corresponded with Dr LeSueur and found out that M. latipinna had a certain mysterious urge to follow and chase troops of specimens of Poecilia (or Cyprinodons [sic]).

Figure 4 (after Heckel, 1848). Detailed drawing of the male copulatory organ, the gonopodium, of Xiphophorus helleri

Heckel (1848) Heckel described Xiphophorus helleri in a detailed report, in which he clearly distinguished both sexes and even discussed the function of the modified anal fin in the male (Fig. 4). Although the relative position of the anal fins were discussed in the male and the female, eliminating in fact the generic difference between Poecilia and Mollienesia, Heckel did not make this conclusion; he still recognized both genera. It must be noted, that although the date of publication of Heckel's paper is stated as 1848 (which was confirmed after checking with the Vienna Museum), the date on the plates is stated as 1852.

Poey(1854) Poey (1854) also commented on the position of the anal fin in poeciliids. He stated that the peculiar position of this fin was present only in males of Mollienesia and that if the males in Poecilia also exhibited this feature, the genus Mollienesia should be abandoned. The only difference between the two genera would than be the size of the dorsal fin, a character that Poey considered insufficient for generic differentiation (but see below). The dorsal fin of Poecilia had 7 to 10 fin rays, while in Mollienesia the dorsal fin contained 12 or more fin rays (Fig. 2A).

Peters (1859) In a short communication, P. reticulata Peters, 1859 from Venezuela was described. The lack of any variation in characters, e.g., 7 dorsal fin rays and 9 anal fin rays, suggests that the From the Amazon river to the Amazon molly and back again: Introduction ix

new species was based on the description of a single female (Poeser and Isbriicker, 2002). Specimens from the same collection were also shipped to London, where they were examined by Günther (Paepke, 1986; see below). As stated above, the males were probably not recognized as conspecific or even congeneric.

DeFilippi(1861) In an inconclusive description, De Filippi diagnosed four specimens of poeciliid fish presumably from Barbados. According to the text, Lebistes poecilioides de Filippi, 1861 was based on two females and two males. However, the accompanying figure, mentioned as a female, probably records a male. The anal fin of this specimen was also figured (De Filippi, 1861, fig. 6b) and clearly shows an elongated anal fin. The meristic data included 9 dorsal fin rays and 7 anal fin rays. Strangely enough, De Filippi also mentioned that there was no difference between the anal fins of both sexes. Based on this description alone, and with the types lost (Nelson, 1998), Lebistes poecilioides is certainly not a guppy (cf. Regan, 1913; Rosen and Bailey, 1963). The taxonomie consequences are that the subgenus Lebistes sensu Rosen and Bailey (1963) was renamed as Acanthophacelus Eigenmann, 1907 (Poeser and Isbriicker, 2002).

Bleeker(1863) Poecilia vivipara was designated by Bleeker (1863) as the type of Poecilia, which genus consisted of nine (unspecified) species (cf. Bleeker, 1860, 1863). The genus was diagnosed by the anatomy of the jaws and dentition, and the relative positions of the dorsal, anal and pectoral fins.

Steindachner(1863) Steindachner allocated Limia Poey, 1854 to Xiphophorus Heckel, 1846, without any further statement or justification. Poecilia mexicana Steindachner, 1863 was described with males and females, again suggesting that the generic differences between Poecilia and Mollienesia were invalid. However, both genera remained separated. In the same paper, Steindachner also described P. thermalis Steindachner, 1863 (type locality: a sulfurous spring "La Esparanza", Chiapas, Mexico).

Peters (1864) Peters re-examined and commented on the holotype of P. vivipara. He corrected the description of the "forked" caudal fin (Fig. 1 A), which split was considered artificially.

Günther (1866) Mollienesia was synonymized with Xiphophorus, based on their broad dorsal fins, whereas Limia was re-allocated from Xiphophorus (cf. Steindachner, 1863) to Poecilia. Günther considered P. surinamensis and P. schneideri conspecific with P. vivipara and his list of x From the Amazon river to the Amazon molly and back again: Introduction

Poecilia contained 16 species with a short dorsal fin. Poecilia thermalis (cf. Steindachner, 1863) was recorded from El Salvador, and Günther only emphasized the occurrence of the El Salvadorian P. thermalis in warm springs, ignoring Steindachner's remarks about the sulfurous environments in which the Mexican types were found. Mollienesia petenensis Günther, 1866 was added as a new species to the genus Mollienesia, based on its broad dorsal fin. Poecilia reticulata Peters, 1859 was considered as Girardinus reticulatus when Günther compared type specimens from the Berlin museum (cf. Paepke, 1986) with a new species, viz., G. guppii Günther, 1866. This specific name prompted the vernacular name for this species, viz., the guppy. In an addendum, Günther doubted the validity of Lebistes de Filippi, 1861, based on the meristic characteristics and the observation that both sexes in this genus had similar anal fins.

Eigenmann (1894) Eigenmann contributed to the 19th century taxonomy of Poecilia by describing P. vivipera (sic) parae (= P. parae) and P. branneri. Eigenmann would later revolutionize poeciliid taxonomy in the 20th century.

Garman (1895) After considering Peter's (1864) remarks and after examining extensive material, Garman considered P. vivipara, P. schneideri, P. unimaculata, P. surinamensis, P. unipunctata Guérin-Méneville, 1929 (from Rio de Janeiro, Brazil) and Girardinus versicolor Günther, 1866 as conspecific. Only the latter the latter species was to be removed subsequently (as Limia versicolor, cf. Regan, 1913). The main distinction between Mollienesia and Poecilia remained the size of the dorsal fin (cf. Günther, 1866). In addition to the generic problems, another critical taxonomie question emerged: the intraspecific differences in the short-finned species were seemingly exceeding the interspecific differences. Garman synonymized, without any clear justification, P. sphenops with Limia couchiana Girard, 1859, P. mexicana, P. thermalis, "Gambusia modesta" Troschel, 1865, "G.plumbea" Troschel, 1865, P. petenensis Günther, 1866, P. dovii Günther, 1866, P. spilurus Günther, 1866, P. butleri Jordan, 1889, and "Mollienesia fasciata" Peters, 1844 (= Molinesia fasciata Muller and Troschel, 1844?). He did, however, recognize the need for a larger series of specimens to decide on the number of varieties that can be included in his P. sphenops. Lebistes poecilioides was included in the genus Poecilia, viz., P. poecilioides, based only on the original description of de Filippi (1861).

Summary of the 19th century taxonomy of Poecilia. Valenciennes (in: Cuvier and Valenciennes, 1846) transformed Poecilia Bloch and Schneider, 1801 from a genus of five doubtful species into a genus with eight other species. From the Amazon river to the Amazon molly and back again: Introduction xi

The designation of P. vivipara as the type species of this genus (Bleeker, 1863) extended the number to nine species. LeSueur (1821) did not know of the sexual dimorphism in the position (and shape) of the anal fin and considered the males of P. multilineata to another genus, viz., Mollienesia. This probably happened also to Girardinus guppii, possibly described after examining males of P. reticulata, and G. reticulatus, redescribed after finding males in the type series of P. reticulata (cf. Paepke, 1986). Strangely enough, in his description of Platypoecilus maculatus, Günther (1866) himself expected that males differed from the females in this species. Although also Heckel (1848) and Steindachner (1863) reported on the sexual dimorphy of the anal fins, and Poey (1854) noticed the doubtful distinction between Poecilia and Mollienesia (but did not know of any males in P. vivipara, nor of females in M. latipinna), the two genera remained separated. Moreover, because the size of the dorsal fins of were emphasized as a generic distinction (Günther, 1866), Poecilia (including Limia) remained separate from Mollienesia, including Xiphophorus.

20th Century taxonomy Eigenmann(1907, 1909) In an attempt to characterize "the guppy", viz., P. reticulata, Eigenmann (1907) figured the tip of the gonopodium in great detail. With the detection of these structures, the gonopodial tip was admitted as a major taxonomie tool. The guppy was allocated to a new genus, viz., Acanthophacelus Eigenmann, 1907. Very soon, two other new species with small multicolored males were also assigned to Acanthophacelus, viz., A. melanzonus Eigenmann, 1909 and ,4. bifurcus Eigenmann, 1909.

Regan (1908, 1913) Regan (1908) examined large series of material of Central American species of Poecilia (cf. Garman, 1895) and removed P. couchiana, P. petenensis, P. spilurus and P. elongata from the synonymy of P. sphenops, while he included eight other nominal taxa, viz., Xiphophorus gillii Kner and Steindachner, 1864, P. chisoyensis Günther, 1866, P. vandepolli van Lidth de Jeude, 1887(including both subspecies), P. boucardi Steindachner, 1878, P. limantouri Jordan and Snyder, 1900, P. latipunctata Meek, 1904, Platypoecilus mentalis Gill, 1876, and P. nelsoni Meek, 1904. With these allocations, Regan extended the range of P. cf. sphenops in morphological characters and in pigmentation (Regan, 1908, fig. 13), as well as the geographical range (from northern Mexico to the Leeward Islands), to its maximum limits. Regan (1913) reorganized the subfamily Poeciliinae with the help of Eigenmann's taxonomie observations, i.e., based on the similar gonopodia (Figs. 5 A-F). Regan allocated most species of Poecilia to Mollienesia, whereas he allocated only P. picta Regan, 1913, P. parae, P. branneri, and P. vivipara in Poecilia. Mollienesia sphenops sensu Regan (1913) included the following taxa: Girardinus caucanus Steindachner, 1880, P. salvatoris Regan, xii From the Amazon river to the Amazon molly and back again: Introduction

1907, P. amates Miller, 1907, P. spilonota Regan 1908, and Platypoecilus tropicus Meek, 1907. Although he omitted to list the complete synonymy of his M. sphenops, P. vandepolli was also included, because Regan mentioned the Dutch Antilles in its range. The guppy was considered as a monotypic genus, Lebistes reticulatus (Peters, 1859), uniting Poecilia reticulata, Lebistes poecilioides, and Girardinus guppii, separating Eigenmann's (1894, 1907, 1909) species into two genera, viz., Poecilia and Lebistes. Regan did not justify the surprising re-establishment of Lebistes as a valid genus, but a contemporary paper (Boulenger, 1912) reported that guppies were the only fish species present on Barbados. This would make Lebistes (presumably described from Barbados) automatically a guppy.

Figure 5 (after Regan, 1913). Gonopodia of Poecilia (A, B, C), Lebistes (D), Limia (E) and Mollienesia (F)

Hubbs (1924a, 1926a) Hubbs (1924a) also used the gonopodium as "chief distinctive feature of the Poeciliidae" (Figs. 6A-C). Hubbs (1926a) furthermore defined "the multitude of races allied to, or inseparable from M. sphenops" as the M. sphenops group. Hubbs was "unable to delimit, in either distribution or in characters, any multitude of elementary species making up the sphenops complex of Middle America. The problem of determining the relationships of the diverse types, many of which have received specific names, is in prospect a most fascinating study." The number of dorsal rays separated this group from M. latipinna and allies. Confused by the characters found in "formosa" and "gracilis", Hubbs was unable to recognize these taxa, even as subspecies of M. sphenops. Based on gonopodial structures, size differences and differences in color patterns, the species of Micropoecilia Hubbs, 1926, viz., M. bifurca, M.parae, M.picta, M. melanzona, and M. branneri were separated from P. vivipara, producing a monotypic genus Poecilia. From the Amazon river to the Amazon molly and back again: Introduction xiii

Girardinus caucanus was also allocated to its own genus, Allopoecilia Hubbs, 1924, based on an incredibly accurate description of the gonopodium (Fig. 6B).

5pr 5al 4pr

Figure 6 (after Hubbs, 1924A) Detailed drawings of gonopodial tips. All rays are numbered (3,4a, 4p, 5a, 5p) and diagnostical features are indicated (ph = gonopodial palp; rs = retrorse spine; mli = membranous hook). A. Neopoecilia holacanthus; B. Allopoecilia cam-ana; C. Mollienesia latipinna xiv From the Amazon river to the Amazon molly and back again: Introduction

Trewavas (1948), Rivas and Myers (1950) The Hispaniolan taxa Psychropoecilia Myers, 1935 and Curtipenis Rivas and Myers, 1950 were considered different from Poecilia and Mollienesia mainly based on the structures of the gonopodium (Fig. 7).

Figure 7. Gonopodia of Psychropoecilia (A; after Myers, 1935) and Curtipenis (B; after Rivas and Myers, 1950)

Rosen and Bailey (1963) In an effort to create order from the chaos of poeciliid taxonomy, Rosen and Bailey lumped the above mentioned Mollienesia, Limia, Lebistes, Acanthophacelus, Pamphorichthys, Allopoecilia, Micropoecilia, Psychropoecilia, and Curtipenis (along with some other, not mentioned, supraspecific taxa, see Appendix 1) in the genus Poecilia, "provisionally arranged in four subgenera", viz., Limia, Lebistes (including Cnesterodon scalpridens, Acanthophacelus and Micropoecilia), Pamphorichthys (including Limia heterandria Regan, 1913 and Parapoecilia hollandi [Henn, 1916]), and Poecilia (including the remaining taxa mentioned above). Some taxa "of doubtful validity" were included. In defense of the From the Amazon river to the Amazon molly and back again: Introduction xv

"pragmatic or philosophical needs of taxonomy", they tried to put a hold on the "strong tendency toward smaller and smaller genera, until a point was reached at which many if not most genera were monotypic. ... the genus is naturally the first of the synthetic categories with which a peace must be made. ... Because the generic name is an integral part of the scientific name, stability in its use is much to be desired, but, even more important, the genus can and must serve to express relationships."

Figure 8 (after Rodriguez, 1997). Pelvic fins of the members of the Poeciliini A. Alfaro B. Xiphophorus C. Poecilia D. Limia E. Pamphorichthys

Rosen and Bailey based the relationships within the Poeciliidae mainly on the shapes of the pelvic fin (Fig. 8) and on internal anatomy (Figs. 9 & 10). Subsequent to this huge revision, the situation concerning the P. sphenops species group remained promising (cf. Hubbs, 1926a). A total of 35 synonyms was listed for Rosen and Bailey's P. sphenops. xvi From the Amazon river to the Amazon molly and back again: Introduction

Figure 9. Skeletons of the species of the tribe Poeciliini (after Rosen and Bailey, 1963). Number and position of the gonapophyses are highlighted. A. Poecilia reticulata B. Pamphorichthys hollandi C. Limia ornata

Schultz and Miller (1971), Menzel and Darnell (1973), Miller (1975, 1983), Rivas (1978) As a reaction to Rosen and Bailey (1963), Schultz and Miller (1971) mentioned "... a thorough study of the whole [P. sphenops] complex and the type specimens will be required before systematic units and the nomenclature can be convincingly coordinated." Species recognition was aided by dental analyses (Schultz and Miller, 1971), i.e., unicuspid and tricuspid species were recognized (Fig. 11). Other alpha-taxonomic features (meristic and morphometric characters, body or fin colors, even allozyme data) remained confusing. Rivas (1978) remarked that "proportional body measurements are [to be] omitted ..., there is considerable variation in characters individually, ontogenetically, seasonally, geographically, and environmentally and, therefore, they are of little or no value in distinguishing species (except relative fin position)." Extensive investigations (Schultz and Miller, 1971; Menzel and Darnell, 1973; Miller, 1975) resulted in a checklist for the Mexican mollies (Miller, 1983), which included four species of Central American members of the P. sphenops complex, viz., P. sphenops, P. mexicana, P. butleri and P. orri Fowler, 1943. The sailfin mollies, P. latipinna, P. velifera (Regan, 1914) and P. kykesis Poeser, 2002 remained valid species, as did From the Amazon river to the Amazon molly and back again: Introduction xvii

P. caucana, P. latipunctata, P. chica Miller, 1975, P. catemaconis Miller, 1975, P. sulphuraria (Alvares, 1948) and the all-female species P. formosa (Girard, 1859), a natural hybrid.

Figure 10 (After Rosen and Bailey, 1963). Details of the gonopoclial suspensoria of species of the tribe Poeciliini A. Alfaro cultratus B. Alfaro huberi C. Poecilia caucana D. Poecilia hispaniolana (Note: The gonopodium of P. hispaniolana [from U.M.M.Z. 160661, herein recorded in Chapter 9, Fig. 6] was identified erroneously as P. elegans, the type species of Curtipenis. The gonopodial suspensorium, therefore, here figured as Fig. 10D, from Rosen and Bailey [1963, fig. 23], is from P. hispaniolana too. The origin of the skeleton [Rosen and Bailey, 1963, fig. 13, P. cf. elegans] is unknown.)

Miller (1975) revalidated Mollienesia as a subgenus, based on the serrae found on gonopodial ray 4a in Poecilia (Fig. 6A), which are absent in Mollienesia (Fig. 6C). xviii From the Amazon river to the Amazon molly and back again: Introduction

Meyer (1983), Greenfield (1990), Poeser (1995; in press), Meyer and Radda (2000) Since a checklist was published (Miller, 1983), several species of short finned mollies were described as new, viz., P. maylandi Meyer, 1983, P. teresae Greenfield, 1990, P. marcellinoi Poeser, 1995, P. dauli Meyer and Radda, 2000, P. koperi Poeser, in press, P. boesemani Poeser, in press, and P. wandae Poeser, in press. Poecilia maylandi was mentioned as a distinct form of tricuspid short finned molly (Schultz and Miller, 1971) endemic to the Rio Balsas system. However, this species was already described as P. sphenops pallida de Buen, 1943. Therefore, P. pallida is retained in this thesis.

Figure 11 (after Schultz and Miller, 1971). Dental characteristics, ranging from purely unicuspid to purely tricuspid. A) Inner jaw tooth of P. nelsoni B-D) Inner jaw teeth of P. nelsoni x marcellinoi hybrids E) Inner jaw tooth of P. marcellinoi

Like Meyer and Radda (2000), I examined the issue of revalidation of Mollienesia as a subgenus. Unlike Meyer and Radda, I do not agree with the assessment of Miller (1975) that a single gonopodial feature separates P. vivipara from all other 34 species in Poecilia, and that the lack of serrae on gonopodial ray 4a can define Mollienesia as a subgenus (see also Rodriguez, 1997). I cannot find any unambiguously morphological character separating Mollienesia from Poecilia (see especially Chapter 5) and also the phylogenetic analysis (Chapter 9) does not support such separation. However, the assessment of Meyer and Radda (2000) again emphasize the importance of a thorough examination of species grouping, subgeneric allocations and generic relationships within the taxonomie framework of the Poeciliini sensu Rosen and Bailey (1963), i.e., between their Poecilia, Xiphophorus, Alfaro Meek, 1912 and Priapella Regan, 1913.

Rivas (1978, 1980), Costa (1991), Meyer (1993), Costa and Sarraf (1997) The first revision of Poecilia sensu Rosen and Bailey (1963), apart from the revalidation of Mollienesia as a subgenus (Miller, 1975), was the re-elevation of Limia as a genus (Rivas, 1978, 1980). Rivas (1978) objected to Rosen and Bailey's (1963) classification: "... [according to] Rosen and Bailey [i.e. on "philosophical grounds"], the genus can and should serve to express relationships. ... In further agreement with Rosen and Bailey's other remarks, generic groups should be constructed on similar standards of morphological distinctiveness.... Admittedly, criteria for generic separation are mostly subjective and, in the end, a genus is accepted or rejected as valid according to the personal judgment of the researcher." From the Amazon river to the Amazon molly and back again: Introduction xix

Figure 12 (after Meyer, 1993). Gonopodia of (A) Micropoecilia parae, (B) M. piet a, (C) M. branneri, and (D) M. bifurca

Costa (1991) noted several characters that united the species of Pamphorichthys and coined these characters "synapomorphies", without any phylogeny as justification. This pseudo-phylogenetic method also re-instated Micropoecilia, while rejecting the classification of Pamphorichthys presented by Costa (cf. Meyer, 1993). Subsequently, Costa and Sarraf (1997) described a new species in the subgenus Lebistes, ignoring the revalidated genus Micropoecilia (cf. Meyer, 1993), to which their new species clearly belongs (Fig. 12).

Poeser (1992, 1995, 1998, 2002a, 2002b, in press), Poeser and Isbriicker (2002) My own work concerned the description and classification of mollies and guppies, for which I first had to establish a standard for species recognition. The first paper, the redescription of P. vandepolli (Chapter 1), could only establish that this species was different, but could not pinpoint the nature of the differences: specific criteria, other that dental characters (Schultz and Miller, 1971) were lacking in molly taxonomy. To investigate the nature of naturally occurring variations in characters, I needed to study general literature on this subject. Differences in meristic characteristics and morphology in fish are influenced by environmental factors, such as temperature and salinity (Hubbs, 1922, 1924b, 1926b). These so-called ecomorphological characters were applicable to P. vandepolli (cf. Feltkamp and Kristensen, 1969), and I wanted to investigate their application in other mollies as well. While examining a large series of P. cf. sphenops deposited in Leiden (cf. Boeseman, 1956), I discovered another character defining mechanism, i.e., character displacement (Chapters 2, 3, and 7). xx From the Amazon river to the Amazon molly and back again: Introduction

Examination of a small series of mollies from Lake Pétèn revealed that this represented a species synonymized with P. sphenops (cf. Rosen and Bailey, 1963), viz., P. petenensis Giinther, 1866. However, this name appeared to be occupied by Mollienesia petenensis Giinther, 1866 (cf. Rosen and Bailey, 1963). Resurrecting the original P. petenensis rendered Mollienesia petenensis a new name, viz., P. kykesis (Chapter 4). From a large collection of P. gillii, a species with a distribution area from Mexico and Guatemala to Colombia, I learned that some features are extremely constant, whereas other characters have minor variations, and yet a third category of characters is extremely variable. Using this information to standardize alpha-taxonomic characters, I was able to classify most, if not all, mollies (Chapter 11). During the investigation of molly characteristics, it was useful to compare the characters of mollies with those of related fish, i.e., guppies (P. reticulata) and their relatives, viz., P. parae, P. picta, P. branneri, P. bifurca and P. minima. While reading the original description of Lebistes poecilioides De Filippi, 1861,1 soon realized that Dr. De Filippi was describing a molly. Re-examining the relevant literature concerning the fish of Barbados (Boulenger, 1912; Regan, 1913; Henn, 1916; Hubbs, 1926a) revealed that the generic name Lebistes was tied to a molly, not to the guppy (Poeser and Isbriicker, 2002). As a consequence, the traditional name of the guppy, viz., Lebistes reticulatus, coined by Regan (1913) and accepted by Rosen and Bailey (1963) as the name for one of their subgenera, must be replaced by the first available name, viz., Acanthophacelus reticulatus Eigenmann, 1907. If the guppy represents a separate subgenus in Poecilia, this subgenus also should be dubbed Acanthophacelus Eigenmann, 1907 (Chapter 7). After surveying the alpha-taxonomic limits of the genus Poecilia, and after comparing these data with relevant cladistic literature (Rosen, 1979; Rodriguez, 1997; Breden et al., 1999), I was able to describe Pseudolimia Poeser, 2002, a new genus for Limia heterandria Regan, 1913 (Chapter 5).

Summary of 20th century Pre-Hennigian taxonomy With the discovery of the gonopodium as a diagnostic tool for poeciliid taxonomy, a multiplicity of genera allied to Poecilia were described. While the core of taxonomie problems in the 19th century concerned only four genera, viz., Poecilia, Mollienesia, Limia and Xiphophorus, nine new genera were described in the first half of the 20th century, viz., Acanthophacelus, Pamphorichthys, Pamphoria Regan, 1913, Neopoecilia, 1924, Parapoecilia Hubbs, 1924, Allopoecilia, Micropoecilia, Psychropoecilia, and Curtipenis. These new genera, together with new definitions for existing genera, caused several allocations and re-allocations of species, confusing the taxonomy of Poecilia and its closest relatives. The classification based on gonopodial structures was abolished by Rosen and Bailey (1963), who revised the Poeciliidae and reduced all above mentioned 19th and 20th century taxa to one single genus, viz., Poecilia, with the exception of Xiphophorus which remained a valid genus. From the Amazon river to the Amazon molly and back again: Introduction xxi

Table I. Rosen and Bailey's (1963) allocation of the species of Poecilia

Poecilia (Poecilia) caucana Formerly Allopoecilia Hubbs, 1924 Poecilia (Poecilia) elegans Illustrations of this species in Rosen and Bailey (1963) are actually P. hispaniolana Rivas, 1978 Poecilia (Poecilia) montana Replacement name for P. dominicensis following the homonymy with P. (Limia) dominicensis Poecilia (Poecilia) vivipara Poecilia (Poecilia) sphenops Listed with 35 synonyms Poecilia (Poecilia) formosa Natural hybrid, all-female species Poecilia (Poecilia) latipinna Poecilia (Poecilia) petenensis Renamed P. kykesis Poeser, 2002 to avoid homonymy with P. petenensis, a synonym of P. sphenops in Rosen and Bailey (1963) Poecilia (Poecilia) velifera Poecilia (Poecilia) latipunctata Poecilia (Poecilia) sulphuraria Poecilia (Lebistes) reticulata Lebistes was replaced by Acanthophacelus (cf. Poeser and Isbriicker [2002]) Poecilia (Lebistes) parae Type species of Micropoecilia Hubbs, 1926 Poecilia (Lebistes) branneri Formerly a species of Micropoecilia Poecilia (Lebistes) amazonica Formerly a species of Micropoecilia Poecilia (Lebistes) scalpridens Type species of Pamphoria Regan, 1913 Poecilia (Pamphorichthys) minor Type species of Pamphorichthys Regan, 1913 Poecilia (Pamphorichthys) hollandi Type species of Parapoecilia Hubbs, 1926 Poecilia (Pamphorichthys) hasemani Poecilia (Pamphorichthys) heterandria Type species of Pseudolimia Poeser, 2002 Poecilia (Limia) vittata Type species of Limia Poey, 1854 Poecilia (Limia) perugiae Poecilia (Limia) melanonotata Poecilia (Limia) nigrofasciata Poecilia (Limia) ornata Assigned to the subgenus Odontolimia Rivas, 1980 Poecilia (Limia) melanogaster Poecilia (Limia) caudofasciata Poecilia (Limia) dominicensis Poecilia (Limia) zonala Poecilia (Limia) nicholsi Poecilia (Limia) versicolor

To the four subgenera of Poecilia, viz., Poecilia, Limia, Lebistes and Pamphorichthys, a fifth subgenus, Mollienesia, was added by Miller (1975). Subsequently, Limia was revalidated to full generic level (Rivas, 1978), as were Pamphorichthys (cf. Costa, 1991) and Micropoecilia (cf. Meyer (1993). However, these re-instatements are not firmly based, lacking any phylogenetic justification (except for Mollienesia [cf. Rodriguez, 1997], which was, however, doubted by another phylogenetic analysis [Breden et al., 1999], see Chapter 9).

References Bleeker, P. 1860. Ordo Cyprini, Karpers.- Act. Soc. Sc. Indo-Neerl. 7 (n.5, deel II): 13,492 pp. Bleeker, P. 1863. Systema Cyprinoideorum revisum.- Ned. Tijdschr. Dierk. I: 187-218. Bloch, M.E., and J.O.G. Schneider. 1801. Systema ichthyologiae.- Berlin, Vols. 1,2, 584 pp. Boeseman, M. 1956. Sobre una coleccion de peces de la republica de El Salvador.- Comun. Inst. trop. Invest. Cient. San Salvador, 5 (2/3): 75-88 xxii From the Amazon river to the Amazon molly and back again: Introduction

Boulanger, E.G. 1912. Notes on the breeding habits of the "Millions" fish (Girardinus poecilioides).- Proc. Zool. Soc. London, 11:906-908 Breden, F., M.B. Ptacek, M. Rashed, D. Taphorn and C.A. Figueiredos. 1999. Molecular phytogeny of the life- bearing fish genus Poecilia (Cyprinodontiformes: Poeciliidae).- Mol. Phyl. and Ev. (12) 2: 95-104. Costa, W.J.E.M. 1991. Description d'un nouvelle espece du genre Pamphorichthys (Cyprinodontiformes: Poeciliidae) du bassin de 1'Araguaia, Bresil.- Rev. Fr. Aquariol. (18) 2: 39-42 Costa, W.J.E.M. and Sarraf, A. 1997. Poecilia (Lebistes) minima, a new species of neotropical poeciliid fish from the Brazilian Amazon.- Ichthyol. Explor. Freshwaters: 185-191 Cuvier, M. le B., and M.A. Valenciennes. 1846. Histoire naturelle des poissons.- Paris, 18, 505 pp. De Filippi, F. 1861. Note Zoologiche. IV. Lebistes nuovo genere di pesce della famiglia dei Ciprinodonti.- Arch. Zool. Anat. Fisiol. (Genova) 1: 69-70 Eigenmann, C.H. 1894. Notes on some South American fishes.- Ann. N. Y. Acad. Sci. v. 7: 625-637 Eigenmann, C.H. 1907. The poeciliid fishes of Rio Grande do Sul and the La Plata Basin.- Proc. U. S. Natl. Mus.: 425-433 Eigenmann, C.H. 1909. Reports on the expedition to British Guiana of the Indiana University and the Carnegie Museum, 1908. Report no. 1. Some new genera and species of fishes from British Guiana.- Ann. Carnegie Mus.: 4-54 Eschmeyer, W.N. 1990. Catalog of the genera of Recent fishes.- California Academy of Sciences: (i-v): 1-697 Garman, S. 1895. The cyprinodonts.- Mem. Mus. Comp. Zool.: 1-179 Greenfield, D.W. 1990. Poecilia teresae, a new species of poeciliid fish from Belize, Central America. Copeia: 449-454 Günther, A. 1866. Catalogue of fishes in the British Museum. Catalogue of the Physostomi, containing the families Salmonidae, Percopsidae, Galaxidae, Mormyridae, Gymnarchidae, Esocidae, Umbridae, Scombresocidae, Cyprinodontidae, in the collection of the British Museum.- Cat. Fishes: i-xv, 1-368 Heckel, J. 1848. Eine neue Gattung von Poecilien mit rochenartigen Anklammerungs-Organe.- Sitzber. K. Akad. wiss. Wien, Math. Nat. CI., 1: 289-303 Henn, A.W. 1916. On various South American poeciliid fishes.- Ann. Carnegie Mus.: 93-142 Hubbs, C.L. 1922. Variations in the number of vertebrae and other meristic characters of fishes correlate with the temperature of the water during development.- Am. Nat. 56: 360-372 Hubbs, C.L. 1924a. Studies of the fishes of the order Cyprinodontes.- Misc. Publ. Mus. Zool. Univ. Mich. (13): 1-31 Hubbs, C.L. 1924b. Seasonal variation in the number of vertebrae of fishes.- Pap. Mich. Acad. Sci., Arts and Letters 2: 207-214 Hubbs, C.L. 1926a. Studies of the fishes of the order Cyprinodontes VI.- Misc. Publ. Mus. Zool. Univ. Mich. 16(1): 1-87 Hubbs, C.L. 1926b. The structural consequences of modifications of the developmental rate in fishes, considered in reference to certain problems of evolution.- Am. Nat. 60 (666): 57-81 Lazara, K.J. 1993. Dating and authorship of new species described in Humbolt and Valenciennes' "Reserches sur les poissons fluviatilis de 1'Amerique Equinoxiale."- Copeia 1993 (4): 1160-1161 LeSueur, C.A. 1821. Description of a new genus and several species of fresh water fish, indigenous to the United States.- Jour. Ac. Nat. Sci. Phil. 2, pt. 1:2-8. Menzel, B.W., and R.M. Darnell. 1973. Systematics of Poecilia mexicana (Pisces: Poeciliidae) in Northern mexico.- Copeia 1973 (2): 225-237 Meyer, M.K. 1993. Re-instatement of Micropoecilia Hubbs, 1926, with a redescription of M. bijurca (Eigenmann, 1909) from Northeast South America (Teleostei, Cyprinodontiformes: Poeciliidae).- Zool. Abh. St. Mus. Tierk. 47 (10): 121-130 From the Amazon river to the Amazon molly and back again: Introduction xxiii

Meyer, M.K., and A.C. Radda. 2000. Notes on the subgenus Mollienesia LeSueur, 1821, with a description of a new species of Poecilia Bloch and Schneider, 1801 (Cyprinodontiformes: Poeciliidae) from Venezuela.- Ann. Naturhist. Mus. Wien, (102B): 75-81 Miller, R.R. 1975. Five new species of Mexican poeciliid fishes of the genera Poecilia, Gambusia, and Poeciliopsis- Occas. Pap. Mus. Zool. Univ. Mich. 672: 1-44 Miller, R.R. 1983. Checklist and key to the mollies of Mexico (Pisces: Poeciliidae: Poecilia, subgenus Mollienesia).- Copeial983 (3): 817-822 Miller, R.R. 1994. Origin and classification of the Liberty Molly. Trop. Fish Hob. (42) 6: 104, 106, 108. Muller, J. and F.H. Troschel 1844. Bericht über die zur Behanntmachung geeigneten.- Verhandlungen der Konigl. Preuss. Akademie der Wissenschaften zu Berlin im Monat Februar 1844. Monatsb. Akad. Wiss. Berlin: 35-36 Paepke, H.-J. 1986. Neues zur Entdeckungsgeschichte von Poecilia reticulata.- Aquarien Terrarien 6 (1986): 192-194 Paepke, H.-J. and M.K.. Meyer 1995. On the identity of Molinesia fasciata Muller & Troschel, 1844 and M. surinamensis Muller & Troschel, 1844 (Teleostei: Poeciliidae). Ichthyol. Explor. Freshwaters: 283-287 Parenti, L.R. and M. Rauchenberger 1989. Systematic overview of the Poeciliines. Chapter 1. Pp. 1-14. In: Meffe, G. K., and F. F. Snelson, Jr. (eds.). Ecology and evolution of livebearing fishes (Poeciliidae). Prentice Hall, 453 pp. Peters, W. 1859. Eine neue vom Herrn Jagor im atlantischen Meere gefangene Art der Gattung Leptocephalus, und über einige andere neue Fische des Zoologischen Museums.- Monatsb. Akad. Wiss. Berlin, 1859: 411- 413 Peters, W. 1864. Über neue Saugethiere, Amphibien und Fische.- Monatsb. Berl. Ak. Wiss.: 381 Poeser, F.N. 1992. Re-establishment and «description of Poecilia vandepolli van Lidth de Jeude, 1887 (Pisces: Poecilinae), with comments on related species.- Stud. Nat. Hist. Caribbbean Region 71: 79-98 Poeser, F.N. 1995. Nonrandom variation in Poecilia marcellinoi n. sp. and P. salvatoris Regan, 1907 in El Salvador (Pisces, Poeciliidae).- Bijdrage tot de Dierkunde 64 (4): 239-252 Poeser, F.N. 1998. The role of character displacement in the speciation of Central American members of the genus Poecilia (Poeciliidae).- Ital. J. Zool. 65, Suppl.: 145-147 Poeser, F.N. 2002a. Poecilia kykesis nom. nov., a new name for Mollienesia petenensis Günther, 1866, with resurrection, «description and designation of a lectotype for Poecilia petenensis Günther, 1866 (Pisces: Poeciliidae).- Contributions to Zoology 70 (4), 2002: 243-246 Poeser, F.N. 2002b. Pseudolimia gen. nov., a new monotypic genus for Limia heterandria Regan, 1913 (Teleostei: Poeciliidae).- Beaufortia 52 (6): 53-56 Poeser, F.N. in press. Geographic variation in Poecilia Bloch and Schneider, 1801 (Teleostei: Poeciliidae), with descriptions of three new species and designation of lectotypes for P. dovii Günther, 1866 and for P. vandepolli van Lidth de Jeude, 1887.- Proc. Biol. Soc. Washington, in press Poeser, F.N., and I.J.H. Isbriicker 2002. Zum wissenschaftlichen Name des Guppy.- DATZ 4/2002: 47-49 Poey, F. 1854. Los guajacones, pescesillos de aqua dulce, in: Memoires sobre la historia natural de la isla de cuba. Havana, 1: 374-392. Regan, C.T. 1908. Pisces.- in: Godman, F. DuC, and O. Salvin, Biol. Cent.-Amer.: 33-160 Regan, C.T. 1913. A revision of the cyprinodont fishes of the subfamily Poeciliinae.- Proc. Zool. Soc. Lond.: 977-1018 Rivas, L.R. 1978. A new species of poeciliid fish of the genus Poecilia from Hispaniola, with reinstatement and «description of P. dominicensis (Evermann and Clark). Northeast Gulf Sci. 2 (2): 98-112 Rivas, L.R. 1980. Eight new species of poeciliid fishes of the genus Limia from Hispaniola.- Northeast Gulf Sci.: 28-38 Rosen, D.E. and R.M. Bailey 1963. The poeciliid fishes (Cyprinodontiformes), their structure, zoogeography, and systematics.- Bull. Am. Mus. Nat. Hist. 126: 1-176 xxiv From the Amazon river to the Amazon molly and back again: Introduction

Schultz, R. J. and R.R. Miller 1971. Species of the Poecilia sphenops group (Pisces: Poeciliidae) in Mexico.- Copeia 1971 (2): 282-290 Steindachner, F. 1863. Beitrage zur Kenntniss der Sciaenoiden Brasiliens und der Cyprinodonten Mejicos.- Sitzber. K. Akad. wiss. Wien, Math. Nat. CI., 48 (1): 162-185 Trewavas, E. 1948. Cyprinodont fishes of San Domingo, Island of Haiti.- Proc. Zool. Soc. Lond. 118 (2): 408- 415