Artificial Key

 

This is an artificial key to adult Goodeids, developed by S. A. Webb and M. L. Miller in 1998, modified by R. R. Miller in 2003 and complemented by M. Koeck in 2011/2012.

 

 

1a. Anterior rays of anal of males shortened and slightly separated from rest of fin by a notch, producing a gonopodium-like pseudophallus; pelvic skeleton present, distributed in Mexico:

Goodeinae 2

1b. Anterior rays of anal of males not shortened and slightly separated from rest of fin by a notch, not producing a gonopodium-like pseudophallus; pelvic skeleton absent, distributed in Nevada:

Empetrichthyinae 43

2a. (1a) Cephalic sensory system only of exposed neuromasts, no supraorbital, mandibular, lacrymal or preopercular pores or canals (occasionally present in large Neotoca bilineata):

Girardinichthyini, Girardinichthys-group 3

2b. Cephalic sensory system present, consisting of supraorbital, mandibular, lacrymal and preopercular canals and pores (exposed neuromasts occur in supraorbital series of some taxa):

10

3a. (2a) Anal fin with 18-26 rays, fin base longer than longest rays (except in female Girardinichthys viviparus):

Girardinichthys 4

3b. Anal fin with 13-17 rays, fin base shorter than longest rays:

5

4a. (3a) Body typically more than a third as deep as SL; breeding male dark but never black, often with yellow in median fins; pigment blotch above anus always large, conspicuous and blackened; dorsal base in male much greater in length than anal base. Pacific Slope, upper ríos Lerma and Balsas basins and Lagunas de Zempoala:

Girardinichthys multiradiatus

4b. Body more slender, usually less than a third as deep as SL; breeding male black; dark blotch above anus small and inconspicous or lacking; dorsal base in male approximately the same length as anal base. Interior, Valle de México:

Girardinichthys viviparus

5a. (3b) Dorsal origin well in advance of pelvic insertion; dorsal rays 29-37:

Hubbsina 6

5b. Dorsal fin behind pelvic insertion; dorsal rays 11-17:

7

6a. (5a) Dorsal rays 29-30; Scales in longitudinal row 29-31; both sexes with numerous dark spots on body and dorsal fin (absent on belly); Pacific Slope, Laguna Zacapu and outlet:

Hubbsina ireneae

6b. Dorsal rays 31-37; Scales in longitudinal row 33-37; males are black in upper part of the body and dorsal fin; Pacific Slope, Lago de Yuriria, Río Lerma basin and Interior, Río Grande de Morelia basin:

Hubbsina turneri (maybe extinct)

7a. (5b) Dorsal fin of male unnotched, anterior rays evenly graded in size with those following, not separated by indented interradial membrane; little or no speckling on dorsum; crescent-shaped pigment spot lacking on caudal base; female with 2 longitudinal stripes, the longer along midside, shorter more variable, originating just above pectoral base; dark spot of varying intensity may be present dorsal to anus, sometimes reaching ventral, longitudinal pigment stripe; body of nonreproductive male with 6-18 thin, dorsoventral bars on posterior half, which may coalesce. Pacific Slope, ríos Lerma-Grande de Santiago basin; interior, Río Grande de Morelia:

Neotoca bilineata

7b. Dorsal fin of male notched, first 4 or 5 rays set apart from those following by indented interradial membrane; fleshy labia nearly concealing modified anterior anal rays of male; speckling on dorsal half body; dark crescent at base of caudal fin:

Skiffia 8

8a. (7b) Scales smaller, 35-40 in lateral series; 11-14 dorsal rays (overlaps N. bilineata), many breeding males with dark pigment over anterior body; fins unpigmented; secondary jaw teeth conical, not bifid. Pacific Slope, Río Lerma basin, including Lago de Pátzcuaro, Lago de Zirahuén; interior, Río Grande de Morelia, MIC:

Skiffia lermae

8b. Scales larger, 30-35 in lateral series; 14-18 dorsal rays; male dorsal, anal and pelvic fins pigmented; secondary jaw teeth bifid

9

9a. (8b) Anterior profile strongly wedge-shaped; cleft of mouth superior; male dorsal fin less prominently notched and male lacking bleck spots on body; weakly rooted jaw teeth; fins dusky. Pacific Slope, Río Teuchitlán, Río Ameca basin, JAL:

Skiffia francesae

9b. Anterior profile blunt; cleft of mouth scarcely superior; male dorsal fin more conspicuously notched and male with variable number of irregular spots on sides; prominentpigment in dorsal, anal and pelvic fins. Pacific Slope, Río Lerma-Río Grande de Santiago basin (above El Salto de Juanacatlán):

Skiffia multipunctata

10a. (2b) Jaw teeth in outer series conical, round in cross section, without lateral shoulders or cusps:

11

10b. Jaw teeth in outer series flattened in cross section, with either lateral shoulders or cusps:

14

11a. (10a) Sixth pelvic ray between preceeding rays and body wall, firmly attached to ventral midline by membrane; body marked posteroventral row of 2-5 black bars or spots, anteriormost extending from anal origin to lateral midline, more posterior patches dispersed relatively evenly, most posterior near midpoint between anal insertion and ventral margin caudal fin; dorsal and anal fins of male with thin, terminal red or yellow band or caudal fin with bright, red-orange band:

Zoogoneticus 12

11b. Sixth pelvic ray not between preceeding rays and body wall, not attached to ventral midline by membrane; body not marked with a posteroventral row of black bars or spots; dorsal and anal fins of male lacking thin, terminal, red or yellow band and caudal fin lacking bright, red-orange band:

22

12a. (11a) Margin of male dorsal and anal fins bright orange or red; caudal fin lacking bright, red-orange band (a thin, faint band may be present); melanophores extending to near terminus of caudal fin in male; snout with prominent lateral stripe:

13

12b. Margin of male dorsal and anal fins cream coloured; caudal fin with bright, red-orange band (less prominent or absent in female); melanophores on caudal fin of male limited to proximal, paddle-shaped region; snout lacking prominent lateral stripe. Río Teuchitlán, Río Ameca-basin, JAL:

Zoogoneticus tequila

13a. (12a) Dorsal fin rays 12 (rarely 11 or 13); dorsal fin base length/Sl ratio 0.16; preorbital length/SL ratio 0.066; 2 conspicous dark brown spots in the hypural plate region also in males within reproductive season; Pacific Slope, middle Río Lerma, Lago de Cuitzeo, La Mintzita spring and Laguna Zacapu:

Zoogoneticus quitzeoensis

13b. Dorsal fin rays 13-14; dorsal fin base length/SL ratio 0.18; preorbital lenght/SL ratio 0.056; 2 conspicous dark brown spots in the hypural plate region lacking in males within reproductive season; Pacific Slope, lower Río Lerma, upper ríos Ameca, Armeria and Santiago basins, Lago de Chapala:

Zoogoneticus purhepechus

14a. (10b) Mouth strongly oblique; snout angular in profile; preorbital, supraorbital and preopercular sensory canals complete; many small spots on sides (extending onto belly in juveniles) fading in large fish; breeding males rarely with a subterminal black band and yellow terminal band in median fins; may reach 170mm SL or larger. Pacific Slope, Río Lerma basin including lagos de Chapala, Yuriria, Cuitzeo, Pátzcuaro and Zirahuén, and nothwestern tributary to Río Balsas; interior, Presa de San Juanico, MIC:

Alloophorus robustus

14b. Mouth approximately horizontal; snout rounded in profile; preorbital canal divided, portion of supraorbital canal missing and preopercular canal broken at angle; rarely reaching 70mm SL:

Girardinichthyini, Allotoca-group 15

15a. (14b) Mandibular sensory pores rarely present (large fish may have fewer than 4); basicaudal spot prominent in large individuals; males with weak lateral stripe that does not extend anteriorly to eye; dorsal and caudal fins with a terminal black band. Interior, Lago de Magdalena basin west of Guadalajara, JAL:

Allotoca maculata

15b. Mandibularsensory pores present; basicaudal spot absent, or if present, weakly developed:

16

16a. (15b) Modal number of dorsal rays 13 or 14. Pacific Slope, Río Balsas basin, from unspecified locality near Los Reyes, MIC:

Neoophorus regalis

16b. Modal number of dorsal rays 16-18:

17

17a. (16b) Eye diameter greater than half head depth at eye; 4 branchiostegal rays; narrow vertical bars present on sides. Interior, basins of Lago de Pátzcuaro, MIC:

Allotoca diazi

17b. Eye diameter less than half head depth at eye, 5 branchiostegal rays:

18

18a. (17b) Modal number of dorsal rays 15 or 16; dark band on male caudal fin:

19

18b. Modal number of dorsal rays 18 or 19; no dark band on male caudal fin:

20

19a. (18a) Male often with lateral stripe from posterior margin of eye to caudal fin base; breeding male with blue to green colour on sides of body and a terminla black band in dorsal and caudal fins; female with 4-11 irregular, lateral bars extending onto back; no thin vertical barring on body; modal anal rays 11 or 12. Pacific Slope, ríos Lerma - Grande de Santiago; interior, Río Grande de Morelia, lagos Yuriria, Cuitzeo, Pátzcuaro, Zirahuén and Laguna San Marcos west of Lago de Chapala:

Allotoca dugesii

19b. Male lacking lateral stripes; breeding males with pigmented dorsal and caudal fins; both sexesheavily speckled; 12-18 narrow, vertical bars along sides; modal anal rays 14. Pacific Slope, uppermost Río Ameca basin, JAL:

Allotoca goslinei

20a. (18b) Dorsal rays not extending to vertical with hypural plate; caudal peduncle depth less than half caudal peduncle length. Basin of Lago de Zirahuén, MIC:

Allotoca meeki

20b. Dorsal rays extending to vertical with hypural plate; caudal peduncle depth greater than or equal to half the caudal peduncle length; strong mottling on body, particularly above midline:

21

21a. (20b) Gill rakers on the first arch 10-13; preopercular canal with 9-10 pores. Río Santa Catarina-Cupatitzio above and below Uruapan, MIC:

Allotoca catarinae

21b. Gill rakers on the first arch 9 or 10; preopercular canal with 8 pores. Lagina Zacapu, MIC:

Allotoca zacapuensis

22a. (11b) Outer series of jaw teeth bifid; no dark blotch immediately posterodorsal to preopercular base:

23

22b. Outer series of jaw teeth not bifid, shouldered or tricuspid; dark blotch immediately posterodorsal to pectoral base:

Allodontichthys 39

23a. (22a) Teeth in outer series firmly attached to jaws:

24

23b. Teeth in outer series loosely atteched to jaws:

37

24a. (23a) Dorsal origin far behind of middle totla length:

25

24b. Dorsal origin set near or in advance of middle total length:

28

25a. (24a) Rudimentary first anal ray visible externally; posterior halves of scales above lateral series with dark pigment, producing speckled appearance; adults occasionally with yellow in terminal parts of dorsal and caudal fins variably speckled. Pacific Slope, ríos Chacala (= Cihuatlán or Marabasco), Cuitzmala and Purificación basin, JAL:

Xenotaenia resolanae

25b. Rudimentary first anal ray not visible externally; scale pigmentation above lateral series not producing speckled appearnace:

Characodon 26

26a. (25b) Base of anal fin (7% SL) and distance between dorsal origin and pelvic insertion short (30% SL); distance from snout to occiput long (27% SL). Interior, Valle de Parras, COAH:

Characodon garmani (extinct)

26b.  Base of anal fin (greater than 7.7% SL to 13.8%) and distance between dorsal origin and pelvic insertion longer (more than 30.3% SL to 43.1%); distance from snout to occiput short (less than 25.1% SL to 16.9%):

27

27a. (26b) Dorsal profile indented at nape; Pacific Slope, lower Río Mezquital, DGO:

Characodon audax

27b. Dorsal profile convex at nape; Pacific Slope, upper Río Mezquital, DGO:

Characodon lateralis

28a. (24b) Caudal-peduncle length equal to or greater than head length:

29

28b. Caudal-peduncle length less than head length:

35

29a. (28a) Caudal-peduncle length greater than head length by half the eye diameter or more; anal base of male straight or curved, nearly parallel with midline posteriorly; anterior lobe anal fin of male with labia conceqaling proximal quarter to half of anal rays:

Ilyodon 30

29b. Caudal peduncle equal to head length; anal of male base curved, approaching orthogonal with midline posteriorly; anterior lobe anal fin of male without labia concealing proximal ends of anal rays; caudal fin of male with variably developed, terminal yellow band:

32

30a. (29a) Lateral line scales 46-55; profile of head concave; pores of the lateral line in the preorbital branch not in a row:

31

30b. Lateral line scales 52-60; profile of head convex; pores of the lateral line in the preorbital branch in a row; Pacific Slope, upper part of the Río San Juan Tacámbaro, MIC:

Ilyodon cortesae

31a. (30a) Each jaw with ca. 25 strongly set outer teeth in uniform row. Pacific Slope, ríos Ameca, Armería, Cihuatlán and Coahuayana basins:

Ilyodon furcidens

31b. Each jaw with ca. 45 weakly set outer teeth in staggered row. Pacific Slope, upper tributaries to Río Balsas except Río San Juan Tacambáro:

Ilyodon whitei

32a. (29b) Dorsal rays 13 or 14; 37-39 lateral line scales. Pacific Slope, Río Ameca and its tributary Río Teuchitlán, JAL:

Ameca splendens

32b. Dorsal rays 15 or 16; 34-37 lateral scales:

Chapalichthys 33

33a. (32b) Terminal, yellow on caudal fin of male band narrow (less than pupil diameter) or lacking; first dorsal ray about half of the length of the second; ca. 9 vertical, lateral bars on body. Pacific Slope, Río Lerma-Río Grande de Santiago basin above El Salto de Juanacatlán, JAL-MIC:

Chapalichthys encaustus

33b. Broad (greater than or equal to diameter of pupil), terminal, yellow band on caudal fin of male; first dorsal ray minute or absent, barely visible externally; female with dark patches over most of body below lateral scale series; male with dark speckling on same region. Pacific Slope, Río Balsas basin at Tocumbo and Presa de San Juanico, MIC.

34

34a. (33b) First dorsal ray minute; most individuals with 16 dorsal rays (rarely 15, very rarely 14) and 15 anal rays (rarely 16, very rarely 14). Tocumbo, MIC:

Chapalichthys pardalis

34b. First dorsal ray absent (very rarely minute); most individuals with 14 dorsal rays (rarely 15, very rarely 16) and 14 anal rays (rarely 15, very rarely 16). Presa de San Juanico, MIC:

Chapalichthys peraticus

35a. (28b) Depressed dorsal fin of mature male reaching vertical with hypural plate; body darkly pigmented with colour on breast, chin, throat and below eye, median fins dark, paired fins dusky; femalebody darkly pigmented, opercle silvery and chin, throat and breats ligthly pigmented and speckled in large adults; no pigment spot near anal fin. Pacific Slope, ríos Lerma-Grande de Santiago basin (Lago de Chapala), ríos Ameca and Armería basins and upper Río Coahuayana; interior, basins of lagunas de Magdalena, Zacoalco, San Marcos, Atotonilco and Zapotlán:

"Xenotoca" melanosoma

35b. Depressed dorsal fin of male not reaching vertical with hypural plate:

36

36a. (35b) Posterior half of caudal peduncle orange to red-orange, extending barely onto caudal fin; fins not darkly pigmented; a dark band extending from dorsal margin opercle along the body posterior to middle of pectoral fin; dorsal surface dusky; female shares dusky dorsum, lighter ventrally with a vertical pigment bar on upper opercle, and lacking irregular spotting on body; pigment spot may occur in region of anal fin. Pacific Slope, tributaries to Río Grande de Santiago near Tepic, independent tributaries south of Tepic, ríos Ameca and Armería basins; interior, endorheic Lago de Magdalena and Río Coahuayana basin:

"Xenotoca" eiseni

36b. Caudal fin dark with terminal yellow band, darkly pigmented dorsal fin and dark pigment on dorsal half of body, chin, lips, cheek, dorsal part of opercle (immature male with less intense pigmentation); female with irregular spotting on body concentrated dorsally (decreasing in intensity with age), and prominent pigment spot on belly near anal fin. Pacific Slope, ríos Lerma-Grande de Santiaog basin; interior, (Lago de Cuitzeo is a new species, in description), Río Grande de Morelia basin; Atlantic Slope, Río Santa María, tributary to Río Pánuco:

Xenotoca variata

37a. (23b) Secondary teeth conical; first shortened anal ray of male not visible externally; snout relatively rounded in lateral aspect. Atlantic Slope and interior, headwaters of Río Santa María above Santa María del Río, north end of valley of San Luis Potosí, and Ilescas, northeast of Zacatecas, ZAC:

Xenoophorus captivus

37b. Secondary teeth bifid, compressed anterioposteriorly; first shortened anal ray of male clearly visible externally; snout wedge shaped in lateral aspect:

Goodeini 38

38a. (37b) Dorsal rays 10 or 11; anal of male with 7 rays comprising anterior lobe; head length approximately equals body depth. Atlantic Slope, Río Pánucobasin, upper Río Verde near La Media Luna, Río Verde and in Puerta del Río, SLP:

Ataeniobius toweri

38b. Dorsal rays 12-15; anal of male with 6 rays comprising anterior lobe; head length less than body depth. Pacific Slope, ríos Lerma-Grande de Santiago basin and closely associated drainages; Atlantic Slope, upper tributaries to Río Panuco:

Goodea 39

39a. (38b) Greatest depth 2.6 to 3.2 times in SL; least depth about two-thirds length of head; width of mouth usually about 3.0 times in head length; Pacific Slope:

Goodea atripinnis

39b. Greatest depth 3.3 to 3.7 times in SL; least depth about half length of head; width of mouth usually about 2.5 times in head length; Atlantic Slope:

Goodea gracilis

40a. (22b) Scales in lateral series 42-52. Pacific Slope, southern tributaries to Río Ameca southwest of Ameca, JAL:

Allodontichthys polylepis

40b. Scales in lateral series 36-44:

41

41a. (40b) Jaw teeth in outer series strongly tricuspid, with prominent shoulders. Pacific Slope, Río Tuxpan and tributaries, upper Río Coahuayana basin, JAL:

Allodontichthys hubbsi

41b. Jaw teeth in outer series shouldered but not tricuspid ecpect in very large individuals.

42

42a. (41b) Lateral stripe continuous; dorsal fin unpigmented. Pacific Slope, Río Tuxpan and tributaries, upper Río Coahuayana basin, JAL:

Allodontichthys tamazulae

42b. Lateral stripe broken into irregular blotches; dorsal fin mostly black or with prominent pattern of dark blotches. Pacific Slope, Río Armería basin and two tributaries to Río Coahuayana:

Allodontichthys zonistius

43a.  (1b) Jaw teeth biserial and conical; jaws unequal (the lower projecting); distance from origin of dorsal fin to caudal base more than one third of SL:

               Empetrichthys 44

43b. Jaw teeth uniserial and bicuspid; Jaws equal (the lower not projecting); distance from origin of dorsal fin to caudal base less than one third of SL:

Crenichthys 45

44a. (43a) 29-30 scales in lateral series; anal rays 14; sides are marked by a rather irregular lateral band; predorsal profile broadly arched; Ash Meadows-spring, Nye County, Nevada:

Empetrichthys merriami (extinct)

44b. 31-32 scales in lateral series; anal rays 12-13; sides are marked by a rather narrow axial streak (faint to obsolescent in E. l. concavus); predorsal profile gently sloping to convex; Pahrump Valley, Nye County, Nevada:

Empetrichthys latos

45a. (43b) Lateral line scales in 30 rows; dorsal rays 12; 1 series of lateral blotches, forming a lateral band in breeding time; Railroad Valley, Nye County, Nevada:

Crenichthys nevadae

45b. Lateral line scales in 28 - 29 rows; dorsal rays 10 - 11; 2 lateral bands, one in the midline, the other on the belly, extending from pelvic to caudal fin; Pahranagat Valley, Nevada

Crenichthys baileyi