Nandus Mercatus
📖 Overview
Nandus Mercatus (Nandus mercatus) is a ray-finned fish of the family Nandidae. It inhabits freshwater waters in pelagic environments. This species can reach a maximum total length of 7 cm. With a trophic level of 3.3, it is a low-level carnivore, feeding on invertebrates and small organisms. It is assessed as Data Deficient on the IUCN Red List.
🔬 Taxonomy
🐟 Physical Description
Dorsal spines (total): 14; Dorsal soft rays (total): 10; Anal spines: 3; Anal soft rays: 5 - 6; Vertebrae: 22. No unique diagnostic character was found for this species, with a combination of the following characters diagnosing it from all congeners: body depth 43.0–43.2% SL, 15 pectoral-fin rays, 29–32 lateral line scales, 11–12 scale rows below the lateral line, and slightly concave predorsal profile. Among Sundaic Southeast Asian congeners, Nandus mercatus is distinguished from N. nebulosus in having a slightly concave (vs. even or slightly convex) predorsal profile, rostral fossa reaching to almost half (vs. more than half) predorsal distance and fewer pectoral fin rays (15 vs. 17–19), and from N. prolixus in having fewer lateral-line scales (29–32 vs. 33–37) and deeper body (43.0–43.2% SL vs. 37.6–40.5). It differs from South Asian congeners N. andrewi and N. nandus in having fewer lateral line scales (29–32 vs. 42–55), fewer scale rows below the lateral line (11–12 vs. 14–18), and deeper body (43.0–43.2% SL vs. 24.3–37.1). Nandus mercatus is distinguished from N. oxyrhynchus in having fewer lateral-line scales (29–32 vs. 37–42) and a more gently-sloping predorsal profile.: fusiform / normal; Cross section: compressed.
🌀 Behaviour
Behavioural data for Nandus Mercatus is currently being reviewed.
🦐 Diet
Diet information for Nandus Mercatus is currently being compiled.
🥚 Reproduction
Reproduction data for Nandus Mercatus is currently being compiled.
🌍 Habitat & Distribution
Freshwater; pelagic; pH range: 4.3 - ?. Tropical; 3°N - 2°N, 103°E - 104°E South East Asia: Indonesia, Sumatra.
🌿 Ecology
📐 Morphometrics
🌡️ Water Parameters & Tolerance
🛡️ Conservation Assessment
📊 Population Risk & Fisheries
🔍 Similar Species
👥 Community & Contribute
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