Corresponding author: Wilson J. E. M. Costa (
Academic editor: J. Maldonado
Three new species are described from the Neotropical region comprising the Cerrado savannas of the central Brazilian plateaus, which is among the most important biodiversity centres in the world. These species are considered closely related to
Costa WJEM (2017) Three new species of the killifish genus
The region comprising the Cerrado savannas of central Brazil has been considered among the most important biodiversity hotspots in the world (
The greatest diversity among species of above sea level
Specimens were captured with small dip nets (40 × 30 cm) and were euthanized soon after collection. Representative live specimens were kept alive for nearly 24 hours, photographed, and then euthanized. Euthanasia was conducted in a buffered solution of tricaine methanesulfonate (MS-222) at a concentration of 250 mg/l, for a period of about 10 minutes, i.e., until opercular movements ceased. Specimens were fixed in formalin for a period of 10 days, and then transferred to 70% ethanol. Collections were made with permits provided by ICMBio (Instituto Chico Mendes de Conservação da Biodiversidade) and methods for euthanasia were approved by CEUA-CCS- Universidade Federal do Rio de Janeiro, Rio de Janeiro Coleção Ictiológica do Centro de Ciências Agrárias e Ambientais, Universidade Federal do Maranhão, Chapadinha
Descriptions of colouration of living fish were based on photographs of both sides of individuals. Photographs were taken in small aquaria around 24 hours after collection. Additional direct observations were made with fish in small transparent plastic bottles just after collection. Measurements and counts follow standard length
Morphometric data appear in Table
Morphometric data of
holotype | paratypes | ||
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male | males (n = 9) | females (n = 6) | |
Standard length (mm) | 27.7 | 20.1–25.5 | 21.4–24.7 |
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Body depth | 22.1 | 21.3–22.3 | 20.5–22.8 |
Caudal peduncle depth | 13.7 | 12.9–14.2 | 12.6–13.4 |
Pre-dorsal length | 77.1 | 74.0–78.5 | 74.7–77.0 |
Pre-pelvic length | 55.9 | 55.7–57.9 | 55.8–57.8 |
Length of dorsal-fin base | 13.5 | 11.2–12.7 | 10.9–12.8 |
Length of anal-fin base | 23.8 | 19.8–21.6 | 19.4–21.0 |
Caudal-fin length | 33.1 | 29.9–32.9 | 26.8–32.0 |
Pectoral-fin length | 21.4 | 19.1–21.5 | 18.0–20.6 |
Pelvic-fin length | 10.8 | 9.4–11.1 | 8.2–9.7 |
Head length | 27.6 | 27.2–30.9 | 27.2–30.0 |
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Head depth | 67.5 | 62.0–70.4 | 63.3–70.9 |
Head width | 70.9 | 66.2–73.3 | 69.6–76.8 |
Snout length | 13.2 | 10.9–13.5 | 12.1–14.1 |
Lower jaw length | 21.6 | 15.9–19.5 | 15.3–21.4 |
Eye diameter | 32.3 | 32.4–35.9 | 32.5–34.7 |
Dorsal and anal fins short, extremity slightly pointed in males, rounded in females. Caudal fin oval, slightly longer than deep. Pectoral fin rounded, posterior margin reaching vertical at 80–90% of length between pectoral-fin and pelvic-fin bases. Pelvic fin small, tip reaching between urogenital papilla and base of 1st anal-fin ray in males, reaching between anus and urogenital papilla in females; pelvic-fin bases medially in close proximity. Dorsal-fin origin on vertical through base of 8th anal-fin ray. Dorsal-fin rays 9–11; anal-fin rays 13–15; caudal-fin rays 30–31; pectoral-fin rays 13; pelvic-fin rays 5–6. No contact organs on fins.
Scales small, cycloid. Body and head entirely scaled, except anterior ventral surface of head. Body squamation extending over anterior 25% of caudal-fin base; no scales on dorsal and anal-fin bases. Frontal squamation F-patterned, rarely E-scale anteriorly overlapping F-scale; E-scales not overlapping medially; scales arranged in regular circular pattern around A-scale without exposed margins. Longitudinal series of scales 29–31; transverse series of scales 9; scale rows around caudal peduncle 16. No contact organs on scales. Cephalic neuromasts: supraorbital 3 + 3, parietal 1, anterior rostral 1, posterior rostral 1, infraorbital 1 + 11 + 1, preorbital 2, otic 1, post-otic 1–2, supratemporal 1, median opercular 1, ventral opercular 1, pre-opercular 2 + 4, mandibular 2–3 + 1, lateral mandibular 1, paramandibular 1.
Jaw teeth numerous, conical, irregularly arranged, outer teeth larger and slightly curved, inner teeth straight. Ventral process angulo-articular short, pointed. Ventral process of palatine short, slightly contacting quadrate. Mesopterygoid slender, posterior tip not reaching metapterygoid. Metapterygoid sub-rectangular, with constriction on middle portion. Dorsal portion of preopercle short and pointed, channel rudimentary. Basihyal sub-triangular, greatest width 50% of length; basihyal cartilage nearly 15% of total basihyal length. Six branchiostegal rays. Second pharyngobranchial teeth absent. Interarcual cartilage rudimentary. Fourth ceratobranchial teeth present, continuously arranged. Gill-rakers on first branchial arch 1 + 8. Vomerine teeth 2–4. Dermosphenotic present. Ventral process of posttemporal absent. Second proximal radial of dorsal fin between neural spines of 19th and 21st vertebrae, first proximal radial of anal fin between pleural ribs of 13th and 15th vertebrae. Total vertebrae 30–31.
Known only from the type locality area, a small stream tributary to the Rio Bandeira, Rio das Garças drainage, upper Rio Araguaia basin, central Brazil, altitude approximately 520 m
Geographical distribution of killifishes of the
From the Latin,
Morphometric data appear in Table
Morphometric data of
holotype | paratypes | ||
---|---|---|---|
male | males (n = 5) | females (n = 7) | |
Standard length (mm) | 28.5 | 22.5–26.6 | 22.9–28.4 |
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Body depth | 21.3 | 21.7–22.7 | 20.9–23.1 |
Caudal peduncle depth | 13.3 | 13.2–14.3 | 12.8–14.1 |
Pre-dorsal length | 72.3 | 73.0–76.2 | 73.8–76.4 |
Pre-pelvic length | 53.7 | 52.6–55.1 | 53.0–56.8 |
Length of dorsal-fin base | 14.6 | 11.2–13.7 | 10.4–13.4 |
Length of anal-fin base | 24.7 | 21.4–25.2 | 20.6–23.3 |
Caudal-fin length | 36.1 | 34.1–38.2 | 34.4–38.7 |
Pectoral-fin length | 20.7 | 19.9–23.3 | 20.3–21.7 |
Pelvic-fin length | 12.4 | 10.6–13.3 | 8.5–11.7 |
Head length | 26.3 | 26.1–28.1 | 26.5–28.1 |
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Head depth | 67.0 | 65.5–71.3 | 66.0–73.5 |
Head width | 69.4 | 67.4–72.7 | 70.9–76.2 |
Snout length | 13.4 | 12.9–15.3 | 13.1–15.6 |
Lower jaw length | 17.5 | 18.4–20.0 | 17.8–19.5 |
Eye diameter | 33.4 | 32.3–35.2 | 28.8–35.8 |
Dorsal and anal fins short, tip slightly pointed in males, rounded in females. Caudal fin oval, longer than deep. Pectoral fin rounded, posterior margin reaching vertical at approximately 80–90% of length between pectoral-fin and pelvic-fin bases. Pelvic fin small, tip reaching between base of first and third anal-fin rays in males, reaching urogenital papilla in females; pelvic-fin bases medially in close proximity. Dorsal-fin origin on vertical through base of 8th anal-fin ray. Dorsal-fin rays 9–10; anal-fin rays 14–15; caudal-fin rays 30–31; pectoral-fin rays 13; pelvic-fin rays 5–6. No contact organs on fins.
Scales small, cycloid. Body and head entirely scaled, except anterior ventral surface of head. Body squamation extending over anterior 25% of caudal-fin base; no scales on dorsal and anal-fin bases. Frontal squamation F-patterned, rarely E-scale anteriorly overlapping F-scale; E-scales not overlapping medially; scales arranged in regular circular pattern around A-scale without exposed margins. Longitudinal series of scales 30–32; transverse series of scales 8; scale rows around caudal peduncle 16. No contact organs on scales. Cephalic neuromasts: supraorbital 3 + 3, parietal 1, anterior rostral 1, posterior rostral 1, infraorbital 1 + 10–11 + 1, preorbital 2, otic 1, post-otic 1, supratemporal 1, median opercular 1, ventral opercular 1, pre-opercular 2 + 4, mandibular 2–3 + 1, lateral mandibular 1, paramandibular 1.
Jaw teeth numerous, conical, irregularly arranged, outer teeth larger and slightly curved, inner teeth straight. Ventral process angulo-articular short, pointed. Ventral process of palatine short, slightly contacting quadrate. Mesopterygoid slender, posterior tip not reaching metapterygoid. Metapterygoid sub-rectangular, with constriction on middle portion. Dorsal portion of preopercle short and pointed, channel rudimentary. Basihyal sub-triangular, greatest width about 50% of length; basihyal cartilage about 15–25% of total basihyal length. Six branchiostegal rays. Second pharyngobranchial teeth absent. Interarcual cartilage rudimentary. Fourth ceratobranchial teeth present, continuously arranged. Gill-rakers on first branchial arch 1 + 8. Vomerine teeth 2. Dermosphenotic present. Ventral process of posttemporal absent. Second proximal radial of dorsal fin between neural spines of 19th and 21st vertebrae, first proximal radial of anal fin between pleural ribs of 13th and 15th vertebrae. Total vertebrae 30–31.
Known only from the type locality, a small stream tributary to the Rio Anhumas, Rio São Lourenço drainage, Rio Paraguai basin, central Brazil, altitude approximately 420 m
From the Latin,
Morphometric data appear in Table
Morphometric data of
holotype | paratypes | ||
---|---|---|---|
male | males (n = 7) | females (n = 7) | |
Standard length (mm) | 26.9 | 24.4–33.3 | 23.7–33.8 |
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Body depth | 23.2 | 21.9–22.6 | 21.6–23.0 |
Caudal peduncle depth | 13.4 | 12.7–13.9 | 12.8–13.6 |
Pre-dorsal length | 73.9 | 72.7–76.5 | 73.8–76.9 |
Pre-pelvic length | 55.4 | 53.8–58.0 | 54.3–57.5 |
Length of dorsal-fin base | 13.6 | 11.5–14.5 | 12.2–13.8 |
Length of anal-fin base | 22.1 | 20.4–24.1 | 18.8–21.1 |
Caudal-fin length | 34.1 | 32.7–33.7 | 31.7–34.9 |
Pectoral-fin length | 21.4 | 20.0–22.2 | 19.2–21.5 |
Pelvic-fin length | 10.7 | 9.6–12.4 | 8.4–10.2 |
Head length | 27.2 | 25.3–27.5 | 24.9–27.2 |
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Head depth | 69.6 | 67.9–73.1 | 69.6–80.4 |
Head width | 73.5 | 71.1–77.2 | 75.5–82.9 |
Snout length | 15.2 | 13.6–17.1 | 13.4–16.2 |
Lower jaw length | 20.1 | 16.6–20.7 | 20.1–23.7 |
Eye diameter | 29.3 | 30.1–33.5 | 30.8–34.2 |
Dorsal and anal fins short, tip slightly pointed in males, rounded in females. Caudal fin oval, slightly longer than deep. Pectoral fin rounded, posterior margin reaching vertical at around 80% of length between pectoral-fin and pelvic-fin bases. Pelvic fin small, tip reaching between urogenital papilla and base of 1st anal-fin ray in males, reaching anus in females; pelvic-fin bases medially in close proximity. Dorsal-fin origin on vertical through base of 8th anal-fin ray. Dorsal-fin rays 10–11; anal-fin rays 14–15; caudal-fin rays 31–33; pectoral-fin rays 13–14; pelvic-fin rays 7. No contact organs on fins.
Scales small, cycloid. Body and head entirely scaled, except anterior ventral surface of head. Body squamation extending over anterior 25% of caudal-fin base; no scales on dorsal and anal-fin bases. Frontal squamation F-patterned, rarely E-scale anteriorly overlapping F-scale; E-scales not overlapping medially; scales arranged in regular circular pattern around A-scale without exposed margins. Longitudinal series of scales 35–37; transverse series of scales 9; scale rows around caudal peduncle 16. No contact organs on scales. Cephalic neuromasts: supraorbital 3 + 3, parietal 1, anterior rostral 1, posterior rostral 1, infraorbital 1 + 10–11 + 1, preorbital 1–2, otic 1, post-otic 1, supratemporal 1, median opercular 1, ventral opercular 1, pre-opercular 2 + 4, mandibular 2–3 + 1, lateral mandibular 1, paramandibular 1.
Jaw teeth numerous, conical, irregularly arranged, outer teeth larger and slightly curved, inner teeth straight. Ventral process angulo-articular short, pointed. Ventral process of palatine short, slightly contacting quadrate. Mesopterygoid slender, posterior tip not reaching metapterygoid. Metapterygoid sub-rectangular, with constriction on middle portion. Dorsal portion of preopercle short and pointed, channel rudimentary. Basihyal sub-triangular, greatest width near 55% of length; basihyal cartilage the 20% of total basihyal length. Six branchiostegal rays. Second pharyngobranchial teeth absent. Interarcual cartilage rudimentary. Fourth ceratobranchial teeth present, continuously arranged. Gill-rakers on first branchial arch 1 + 7–8. Vomerine teeth 2–5. Dermosphenotic present. Ventral process of posttemporal absent. Second proximal radial of dorsal fin between neural spines of 19th and 21st vertebrae, first proximal radial of anal fin between pleural ribs of 14th and 15th vertebrae. Total vertebrae 32.
Known only from the type locality, Ribeirão da Sobra, an upper tributary of the Rio Itiquira, Rio Paraguai basin, central Brazil, in altitude about 750 m
From the Latin,
1 | In females, ventral surface of head with dark grey spots, often forming short stripe on chin; in males, caudal fin never with broad bright orange band along entire margin |
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– | In females, ventral surface of head without dark grey spots; in males, caudal fin with broad bright orange band along margin |
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2 | 7 pelvic-fin rays; 35–37 scales in longitudinal series; female caudal spot conspicuous in live fish |
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– | 5–6 pelvic-fin rays; 29–32 scales in longitudinal series; female caudal spot inconspicuous in live fish |
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4 | Caudal fin, in males, without bars; caudal fin, in females, pale yellow; anal fin, in males, bright red-orange; caudal-fin length 26.8–33.1% |
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– | Caudal fin, in males, with 7–8 red bars; caudal fin, in females, pale yellow on middle portion and orange on marginal portion; anal fin, in males, light yellow; caudal-fin length 34.1–38.7% |
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Morphological characters indicate that all three new species here described are more closely related to
Dorsal branchial arches, left side, ventral view, of
Relationships among species of the
Diagrammatic representation of the colour pattern on the ventral surface of the head in females of
Osteological characters have been used to infer relationships among species groups of
Jaws, jaw suspensorium and opercular apparatus, left side, lateral view, of
Basihyal and ventral branchial arches, right and median portion, dorsal view, of
Recent killifish inventories in the area of the central Brazilian plateaus drained by the upper tributaries of the Araguaia, Paraná and Paraguai river basins have revealed an unexpected high diversity of species of the genus
I am grateful to Bruno Costa, Claudia Bove, and Stephanie Vaz, for help during field studies, and to Thomas and Paula Philbrick for the kind companionship during the trip. The manuscript benefited from corrections and suggestions made by Thomas Philbrick and Donald Taphorn. This study was supported by CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico - Ministério de Ciência e Tecnologia).