Taxonomic revision of the seasonal South American killifish genus Simpsonichthys (Teleostei: Cyprinodontiformes: Aplocheiloidei: Rivulidae).
Author
Wilson J. E. M. Costa
text
Zootaxa
2007
1669
1
134
http://www.zoobank.org/urn:lsid:zoobank.org:pub:F23FABE8-719E-4F7E-B225-A9C5D45CCFCE
journal article
z01669p001
Simpsonichthys adornatus
Costa, 2000
(Figs. 55-56)
Simpsonichthys adornatus
Costa, 2000: 9 (
type locality: temporary pool near
Sitio
do Mato, rio
Sao
Francisco basin
,
Estado da Bahia
,
Brazil
[
13º00’46.1”S
43º28’50.0”W
; altitude 463 m];
holotype
:
MZUSP
54563
).
Material examined
Brazil
:
Estado da Bahia
, rio
Sao
Francisco basin floodplains:
MZUSP
54563
,
holotype
, male, 44.5 mm SL;
UFRJ
4805
, 18
paratypes
;
UFRJ
4806
, 1
paratype
;
temporary pool 8 km N of
Sitio
do Mato
;
W. J. E. M. Costa, F. M. Pupo & E. S. Araujo
,
12 Feb. 1999
.
MZUSP
54564
, 10
paratypes
;
MCP
22262
, 20
paratypes
;
UFRJ
5188
, 20
paratypes
;
UFRJ
5189
, 10
paratypes
;
UFRJ
4807
, 8
paratypes
(c&s);
1.5 km N from the type locality
;
same collectors
,
15 Feb. 1999
.
Diagnosis
Readily distinguished from all other aplocheiloids by the possession of numerous dorsal-fin rays in males (28-32, vs. 5-25). Probably related to the high number of dorsal-fin rays, it also differs from all other rivulids by possessing the dorsal-fin origin inserted near the nape, between neural spines of third and fourth vertebrae (vs. between neural spines of vertebrae 6 and 20). Differs from all other species of
Simpsonichthys
by having the flanks light blue, with longitudinal rows of minute bluish white spots in males (vs. never a similar color pattern), well defined horizontal rows of small dark brown spots on flanks in females, and two rounded black spots vertically arranged on posterior portion of caudal peduncle in females (vs. never similar color patterns).
FIGURE
55.
Simpsonichthys adornatus
, male, MZUSP 54563, holotype, 44.5 mm SL; Brazil: Bahia:
Sitio
do Mato.
FIGURE 56.
Simpsonichthys adornatus
, female, UFRJ 4806, paratype, 37.1 mm SL; Brazil: Bahia:
Sitio
do Mato.
Description
Morphometric data appear in Table 5. Largest specimen examined 45.1 mm SL. Dorsal profile convex from snout to end of dorsal-fin base, approximately straight on caudal peduncle. Ventral profile convex from lower jaw to end of anal-fin base, nearly straight on caudal peduncle. Body deep, compressed, greatest body depth at level of pelvic-fin base. Eye positioned on dorsal portion of side of head. Snout blunt. Urogenital papilla cylindrical and short in males, pocket-shaped in females.
Tip of dorsal fin pointed in males, rounded in females; tip of anal fin rounded in both sexes. Short filamentous ray on tip of dorsal fin in males, reaching vertical through middle of caudal fin; filaments absent in anal fin. Dorsal-fin rays unbranched. Caudal fin rounded. Pectoral fins elliptical. Posterior margin of each pectoral fin reaching vertical through base of 5th anal-fin ray in males, and between pelvic-fin base and urogenital papilla in females. Tip of each pelvic fin reaching base of 4th anal-fin ray in males and base of 1st analfin ray in females. Pelvic-fin bases in close proximity. Dorsal-fin origin anterior to anal-fin origin in males, anal-fin origin on vertical through base of 5th dorsal-fin ray; dorsal-fin origin posterior to anal-fin origin in females, on vertical through base of 3rd or 4th anal-fin ray. Dorsal-fin origin between neural spines of vertebrae 3 and 5 in males, and neural spines of vertebrae 11 and 12 in females. Anal-fin origin between pleural ribs of
vertebrae
6 and 7 in males, and pleural ribs of vertebrae 8 and 10 in females. Dorsal-fin rays 28-32 in males, 14-19 in females; anal-fin rays 21-24 in males, 18-22 in females; caudal-fin rays 22-24; pectoral-fin rays 12-13; pelvic-fin rays 5-6.
Frontal squamation E-patterned; E-scales overlapping medially; no row of scales anterior to G-scale; supraorbital scales 2. Longitudinal series of scales 27-29; transverse series of scales 10; scale rows around caudal peduncle 12. Contact organ on each scale of flank and ventral portion of opercle in males. Small papillate contact organs on inner surface of three dorsalmost rays of pectoral fins in males.
Cephalic neuromasts: supraorbital 14-17, parietal 2, anterior rostral 1, posterior rostral 1, infraorbital 2 + 23-25, preorbital 3, otic 1, post-otic 2, supratemporal 1, median opercular 1, ventral opercular 1, preopercular 14-18, mandibular 12-13, lateral mandibular 5, paramandibular 1. One neuromast on each scale of lateral line. Two neuromasts on caudal-fin base.
Basihyal subtriangular, width about 50% of length; basihyal cartilage about 25% of total length of basihyal. Six branchiostegal rays. Second pharyngobranchial teeth 1-3. Gill-rakers on first branchial arch 2 + 9. Vomerine teeth absent. Dermosphenotic absent. Ventral process of posttemporal long. Total vertebrae 27- 29.
Coloration
Males. Sides of body light blue to purplish blue, with longitudinal rows of white dots, anterior dots vertically elongated; faint gray bars alternating with pale red bars on anterior portion of flanks. In preserved specimens, about 15 faint gray bars on flank. Sides of head light blue, opercular region bright greenish blue; posterodorsal scales with red margin. Iris pale yellow with black bar through center of eye. Unpaired fins dark bluish gray, with bluish white dots, basal region yellowish gray; anterior third of dorsal fin with bright blue oblique lines. Pelvic fins dark yellowish gray. Pectoral fins hyaline.
Females. Sides of body light purplish gray, golden on venter, with horizontal rows of small, dark brownish gray spots, sometimes coalesced to form horizontal stripes; spots on anterocentral portion of flanks black. Two round black blotches, vertically arranged, on posterior portion of caudal peduncle. Iris light yellow, with dark gray bar through center of eye. Opercular region light blue, with small gray spots. Unpaired fins and pelvic fins hyaline, with small dark brownish gray spots; small light blue spot on posterior margin of anal fin, just posterior to fin base. Pectoral fins hyaline.
Distribution
Floodplains of middle rio
Sao
Francisco, Estado da Bahia, northeastern Brazil (Fig. 4).
Habitat
Temporary pools in the Caatinga.