分類 / 名前
共通名の | 類義語 | Catalog of Fishes(部類, 種) | ITIS | CoL | WoRMS | Cloffa
>
Characiformes (Characins) >
Acestrorhamphidae (American tetras) > Acestrorhamphinae
Etymology: Astyanax: The name of Astyanax, Hector´s son in the Greek mythology (Ref. 45335); courensis: Named for its type locality, rio dos Couros, an important tributary of rio Tocantinzinho, upper rio Tocantins basin; adjective.
Eponymy: Astyanax was the son of Hector in Greek mythology. See Homer’s Iliad for details. The reasoning for its use for a genus of characins is not explained. (Ref. 128868), visit book page.
環境:環境 / 気候帯 / 深さの範囲 / 分布範囲
生態学
; 新鮮な水 外洋の; 深さの範囲 ? - 2 m (Ref. 84461). Tropical; 14°S - 15°S, 47°W - 48°W
South America: known from the rio dos Couros basin, tributary of rio Tocantinzinho, upper rio Tocantins basin, Alto Paraíso de Goiás, Chapada dos Veadeiros, Goiás State, Brazil (Ref. 84461).
サイズ / 重さ / 年齢
成熟: Lm ?  range ? - ? cm
Max length : 7.2 cm SL オス/雌雄の選別がない; (Ref. 84461)
簡単な記述
検索表 | 形態学 | 形態計測学
Astyanax courensis belongs to the A. scabripinnis species complex and is distinguished from other species of this complex by the number of scale rows between lateral line and pelvic fin origin (3-4 vs. 5-6), except from A. brachypterygium, A. burgerai Zanata & Camelier, A. goyanensis, A. intermedius Eigenmann, A. jenynsii, A. microschemos, A. rivularis Lütken, A. totae, and A. varzeae. It differs from A. brachypterygium, A. goyanensis, and A. totae by head length (24.9-28.2% SL, mean = 26.6 vs. 27.8-33.2, mean = 29.9, 27.7-32.3, mean = 31.6, and 27.9-32.8, mean = 29.7, respectively), and by the number of humeral spots (1 vs. 2, except in A. totae, which has one). It differs from A. burgerai and A. intermedius by shape of the dentary teeth (abruptly decreasing in size after fourth tooth vs. teeth gradually decreasing in size posteriorly), and orbital diameter (24.9-31.9% HL, mean = 27.9 vs. 34.6-40.6, mean = 38.0, 32.5-47.8, mean = 39.0, respectively); from A. jenynsii by the number of branched anal-fin rays (15-17, mean = 15.8 vs. 13-15, mean =14) and upper jaw length (40.6-50.0% HL, mean = 44.9 vs. 35.9-39.5, mean = 37.4); from A. rivularis by body depth (27.4-33.1% SL, mean = 30.5 vs. 35.0-46.0, mean = 40.3), and by the number of humeral spots (1 vs. 2); from A. varzeae by the number of lateral line scales (35-36, mean = 35.4 vs. 37-42, mean = 39), caudal-peduncle length (13.6-16.9% SL, mean =15.2 vs. 10.5-13.9, mean = 12.4) and orbital diameter (24.9-31.9% HL, mean = 27.9 vs. 30.9-44.5, mean = 37.9). Furthermore, it differs from A. microschemos and A. totae by the number of maxillary teeth (1 vs. 2-3 and 2-5, respectively). Astyanax courensis differs from only sympatric Astyanax species, A. goyanensis, by the number of pelvic-fin rays (8 vs. 7), and number of maxillary teeth (1 vs. 2-5), and by prepectoral distance (23.7-27.8% SL, mean = 26.4 vs. 27.7-32.0, mean = 30.4) (Ref. 84461).
The collection locality is around 1135 m above sea level, rio dos Couros in that point has moderate riparian vegetation and it is typically between 10 and 15 m wide, and 1.5 m deep. Although presenting some rapids, the water is clear, the substrate has stones, rocks, and some stretches with mud. Most of the specimens were collected on the stretch downstream from the waterfall, a few specimens on the stretch upstream of waterfall. Only 4 species were collected syntopically with A. courensis: Characidium stigmosum,
C. aff. zebra, Gymnotocinclus anosteos and Trichomycterus sp. The stomach contents of five specimens consisted of Plecoptera, Trichoptera, Chironomidae (Diptera), authochthonous and allochthonous insects, and digested vegetal organic matter; these stomachs were partially full (Ref. 84461).
ライフサイクルと交尾行動
成熟 | 繁殖 | 放精 | 卵 | 生産力 | 幼生
Bertaco, V.A., F.R. Carvalho and F.C. Jerep, 2010. Astyanax goyanensis (Miranda-Ribeiro, 1944), new combination and Astyanax courensis, new species (Ostariophysi: Characiformes): two Characidae from the upper rio Tocantins basin, Central Brazil. Neotrop. Ichthyol. 8(2):265-275. (Ref. 84461)
IUCNのレッドリストの状況は (Ref. 130435: Version 2025-2 (Global))
人間の用途
水産業: 興味がない
用具
特記事項
XMLをダウンロードして下さい
インターネットの情報源
モデルに基づく推定値
系統多様性指数 (参照 82804) |
PD50 = 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high]. |
|
Bayesian length-weight
|
a=0.01047 (0.00461 - 0.02381), b=3.11 (2.93 - 3.29), in cm total length, based on LWR estimates for this Genus-body shape (Ref. 93245). |
栄養段階 (参照 69278) |
3.0 ±0.4 se; based on size and trophs of closest relatives |
漁業の脆弱性 (Ref. 59153) |
Low vulnerability (15 of 100). 🛈 |