分類 / Names
共通名の | 類義語 | Catalog of Fishes(部類, 種) | ITIS | CoL | WoRMS | Cloffa
Issue
The high level of genetic divergence between most of the populations in South Africa suggests that it may represent a species complex rather than a single species (Ref. 32965, 93589). There is an urgent need for detailed morphological diagnostic studies, and the determination of the ecological requirements and conservation status of each of the cryptic forms of this species (Ref. 93589).
Environment: milieu / climate zone / depth range / distribution range
生態学
; 新鮮な水 底生の漂泳性. Subtropical; 18°C - 24°C (Ref. 12468); 30°S - 34°S
Africa: endemic to South Africa, occurs in Cape coastal streams and rivers from the Krom and upper Gamtoos River systems (south coast) to the Clanwilliam Olifants system (west coast)(Ref. 32965, 52193, 93589, 93786).
Length at first maturity / サイズ / 重さ / 年齢
Maturity: Lm 3.9, range 4 - 4 cm
Max length : 7.5 cm TL オス/雌雄の選別がない; (Ref. 52193)
簡単な記述
検索表 | 形態学 | 形態計測学
背面の脊椎 (合計) : 0; 背鰭 (合計) : 9 - 13; 肛門の骨: 0; 臀鰭: 9 - 14; 脊つい: 36 - 42. Diagnosis: body slender and cylindrical, without scales; dorsal fin placed far back over anal fin; caudal fin truncated; mouth terminal, jaws with teeth; large eyes; internal organs visible in live specimens (Ref. 52193). Loss of two laterosensory pores beneath the lower jaw; elongate caudal peduncle (Ref. 93822).
Facultative air-breathing in the genus (Ref. 126274); May penetrate some distance inland and is widespread in lakes and rivers (Ref. 3563), which may be either acid (pH 5-6,5) or alkaline (pH 8-9) (Ref. 93592, 93822). Prefers gentle currents within shelter of banks near the head of pools (Ref. 3563, 52193). Small but extremely hardy, they are known to tolerate a wide range of water and temperature conditions (Ref. 5214, 6164, 52193, 93591, 93592). Feeds on small drifting invertebrates (Ref. 7248, 52193). Spawning period occurs in spring up to middle of summer (Ref. 5214, 33843, 52193), depending on the conditions (Ref. 52193). Ripe eggs are demersal, relatively large and numbering about 30-40 (Ref. 93592). Their small size and cryptic color enable them to avoid predators (Ref. 52193).
Breeding occurs in spring or summer depending on local conditions (Ref. 52193). Galaxias zebratus does not migrate to the sea for breeding purposes (Ref. 41543, 93592).
Skelton, P.H., 2001. A complete guide to the freshwater fishes of southern Africa. Cape Town (South Africa): Struik Publishers, 395 p. (Ref. 52193)
Human uses
水産業: 興味がない; 水族館・水槽: 商業
用具
特記事項
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インターネットの情報源
Estimates based on models
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00490 (0.00205 - 0.01170), b=3.12 (2.91 - 3.33), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref.
93245).
栄養段階 (Ref.
69278): 3.5 ±0.37 se; based on food items.
回復力 (Ref.
120179): 低い, ４．５年～１４年の倍増期間の最小個体群 (Fec<50).
Fishing Vulnerability (Ref.
59153): Low vulnerability (10 of 100).
