 Leptolpanchax sanguineus, Costa 2019 |
History
Specimens found between 1985 and 1988 in the Magé River Basin, south-eastern Brazil were misidentified as L. splendens. The recent rediscovery of other specimens in the Estrela River Basin near the type locality of L. splendens has clarified the species’ concept, making it possible to recognise the Magé River Basin specimens as a new species. The new species is herein described as Leptopanchax sanguineus sp. nov. and is distinguished from all other cynopoecilines by a unique colour pattern in males, including red bars with sinuous margins. It was collected in a well-preserved, temporary shallow swampy area within dense moist forest, but since 1990 the species has not been found again. Leptopanchax sanguineus sp. nov. is one of three species of cynopoeciline killifishes living in lowland moist forests of the coastal plains of Rio de Janeiro State, where the greatest diversity of endemic cynopoecilines is concentrated. Each of these species has been recorded a single time in the last 30 years, a surprisingly low record attributable to intense deforestation during the last several decades resulting in small fragmented lowland moist forests of today. This study indicates that seasonal killifishes adapted to uniquely live in this kind of habitat should be regarded with special concern in studies evaluating conservation priorities.
Diagnosis: Leptopanchax sanguineus differs from other cynopoecilines, except L. splendens, by the presence of red bars on the whole flank in males (vs. absence); uniquely in L. sanguineus, the bars are broad, wider than the interspace width (vs. narrow, half interspace width or less) and have sinuous margins (vs. straight). Leptopanchax sanguineus is further distinguished from L. splendens by having 15 dorsal-fin rays (vs. 12–14), 6 pelvic-fin rays (vs. 5), 27 scales on the longitudinal series and 9 on the transverse series (vs. 24–25 and 7, respectively), 29 vertebrae (vs. 26–27), pelvic fin tip posteriorly reaching the anal fin in males (vs. reaching urogenital papilla), pelvic-fin bases medially separated, in close proximity (vs. medially united), absence of filamentous rays on the caudal fin (vs. short filamentous rays on the posterior margin of the caudal fin in males), presence of a golden stripe on the distal margin of the dorsal fin in males (vs. white stripe), absence of contact organs on the male pectoral fin (vs. presence) and absence of the dermosphenotic bone (vs. presence). Leptopanchax sanguineus also differs from L. splendens and all other cynopoecilines by the presence of a small red spot on the posterior portion of the iris (vs. spot absent).
Etymology: The name sanguineus, from the Latin, meaning blood-coloured, is an allusion to the predominantly red colouration in males, unique among Neotropical killifishes.
Key to identification of Leptopanchax species.
1. Flank in males with continuous longitudinal rows of iridescent light blue to yellowish green spots on each scale (Fig. 2E–F); no horizontal red stripe on head side (Fig. 2E–F); dorsal-fin origin in vertical between base of seventh and ninth anal fin rays ...................................................2
Flank in males with interrupted zones of iridescent marks (Fig. 2A–D); horizontal red stripe between orbit and preopercle in males (Fig. 2A–D); dorsa fin origin in vertical between base of second and sixth anal-fin rays...........................3
2. Well-delimited dark-red stripe on distal margins of dorsal and anal fins in
males(Fig. 2F)..............L. opalescens
-Diffuse dark-reddish brown pigmentation on distal margins of dorsal and anal fins in males (Fig.2E)......................L. citrinipinnis3. Iris bright greenish yellow in males (Fig. 2C, D); no bars on flank (Fig.
2C,D ............................................4 - Iris bright blue in males (Fig. 2A, B); red bars on flank in males (Fig. 2A, B)................................................5
4. Two dark-red stripes along entire dorsal and ventral submarginal parts of caudal
fin in males (Fig. 2C); male caudal-fin stripes branching posteriorly (Fig.
2C); dark red to dark brown short transverse bars on basal portion of dorsal
fin in males (Fig. 2C)......................L. aureoguttatus-Two dark-red stripes on anterior portion of dorsal and ventral submarginal parts of caudal fin in males (Fig. 2D); male caudal-fin stripes not branching posteriorly (Fig. 2D); small brownish orange spots on basal portion of dorsal
fin in males (Fig. 2D) . L. itanhaensis
straight margins (Fig. 2B); distal margin of dorsal fin with narrow bluish white stripe in males (Fig. 2B); 12–14 dorsal-fin rays; 5 pelvic-fin rays; 24–25 scales on longitudinal series; 7 scales on transverse series; pelvic fin tip posteriorly reaching urogenital papilla; pelvic-fin bases medially united; with filamentous rays on distal margin of dorsal fin and posterior margin of caudal fin in males (Fig. 2B) ..............................L.splendens Flank in males with broad red bars, wider than interspace width, with sinuous margins (Fig. 2A);distal margin of dorsal fin with broad golden stripe in males (Fig. 2A); 15 dorsal-fin rays; 6 pelvic-fin rays; 27 scales on ongitudinal series; 9 scales on transverse series; pelvic fin tip posteriorly reaching anal-fin in males; pelvic-fin bases medially separated; absence of filamentous rays on fins (Fig. 2A) ....L. sanguineus sp. nov.
Reproduction
The habitats of all Leptopanchax species are found not far from the city of Rio de Janeiro, often along the coastline in lowlands, that had good cover of forest canope, from southern Bahia state to Parana and Sao Paulo states. Nowadays most forests are gone due to urbanisation and the habitats are changed dramatically or disappeared at all. Only a few refugee habitats are still in tact and are protected now. All Leptopanchax species are declared to be endangered species.
There are only a few of them in the hobby and collecting others is not allowed anymore by the Brasilean laws. For that - and as result of the bad enviormental situation for these fishes -most known Leptopanchax will not become available anymore.
What we do know about reproduction is not very much. The genus shows annual behavior as eggs need to undergo several stages of diapause.
Remarks:
Variations
Map
Meristics
Max. size 00 mm in males - female smaller.
Dorsal (average, male only ) 00.0,
Anal (average, male only ) 00.0,
D/A (average, male only ) 0.0,
LL scale count (average) 00.0
Pre- dorsal length to SL – 00.0 %
Depth to SL – 00.0 %
Vertebrae count (average) 00.0
Literature
Wilson J. E. M. Costa. 2019. Description of A New Species of Cynopoeciline Killifish (Cyprinodontiformes, Aplocheilidae), possibly Extinct, from the Atlantic Forest of south-eastern Brazil. ZooKeys. 867: 73-85. DOI: 10.3897/zookeys.867.34034
Wilson J. E. M. Costa, José L. O. Mattos and P. F. Amorim. 2019. Rediscovery of Leptopanchax splendens (Cyprinodontiformes: Aplocheilidae): A Seasonal killifish from the Atlantic Forest of south‐eastern Brazil that was recently considered extinct. Journal of Fish Biology. DOI: 10.1111/jfb.13898
Costa, W.J.E.M. 2016. Comparative Morphology and Classification of South American cynopoeciline killifishes (Cyprinodontiformes: Aplocheilidae), with Notes on Family-group Names used for aplocheiloids. Vertebrate Zoology, 66 (2): 129.