{"product_id":"harlequin-rasbora-trigonostigma-heteromorpha","title":"Harlequin Rasbora (Trigonostigma heteromorpha)","description":"\u003cbody\u003e\n\n\n  \n\u003cmeta name=\"viewport\" content=\"width=device-width,initial-scale=1.0\"\u003e\n  \u003ctitle\u003eHarlequin Rasbora - Superior Shrimp and Aquatics\u003c\/title\u003e\n  \u003clink href=\"https:\/\/fonts.googleapis.com\/css2?family=Playfair+Display:wght@400;600;700\u0026amp;family=DM+Sans:wght@300;400;500\u0026amp;display=swap\" rel=\"stylesheet\"\u003e\n  \u003cstyle\u003e\n\n    .ssa-pd *, .ssa-pd *::before, .ssa-pd *::after { box-sizing: border-box; }\n    @keyframes fadeUp { from { opacity: 0; transform: translateY(16px); } to { opacity: 1; transform: translateY(0); } }\n    .ssa-pd { font-family: 'DM Sans', sans-serif !important; color: #1e1a1a !important; background: #fff !important; line-height: 1.75 !important; }\n    .ssa-pd .hero { background: linear-gradient(150deg, #111111 0%, #2a0000 60%, #F40909 100%) !important; 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}\n    .ssa-pd .policy-bar a:hover { background:#F40909 !important; }\n  \n  \u003c\/style\u003e\n\n\n\u003cdiv class=\"ssa-pd\"\u003e\n  \u003cdiv class=\"hero\"\u003e\n    \u003cstyle\u003e.ssa-pd .hero::before{content:\"\u0026#128032;\";}\u003c\/style\u003e\n    \u003cspan class=\"hero-tag\"\u003eFreshwater Fish\u003c\/span\u003e\n    \u003ch1\u003eHarlequin Rasbora\u003c\/h1\u003e\n    \u003cp class=\"hero-sub\"\u003eOne of the most enduringly popular schooling fish in the hobby. A copper-red metallic body carrying a bold black triangular wedge, kept in aquariums worldwide for over a century.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"feature-pills\"\u003e\n    \u003cspan class=\"fpill\"\u003e\u003cspan class=\"dot\"\u003e\u003c\/span\u003e Copper-Red Body with Black Triangle\u003c\/span\u003e\n    \u003cspan class=\"fpill\"\u003e\u003cspan class=\"dot\"\u003e\u003c\/span\u003e Trigonostigma heteromorpha\u003c\/span\u003e\n    \u003cspan class=\"fpill\"\u003e\u003cspan class=\"dot\"\u003e\u003c\/span\u003e Peaceful Schooling Fish\u003c\/span\u003e\n    \u003cspan class=\"fpill\"\u003e\u003cspan class=\"dot\"\u003e\u003c\/span\u003e pH 5.0–7.5\u003c\/span\u003e\n    \u003cspan class=\"fpill\"\u003e\u003cspan class=\"dot\"\u003e\u003c\/span\u003e 5 to 8 Year Lifespan\u003c\/span\u003e\n    \u003cspan class=\"fpill\"\u003e\u003cspan class=\"dot\"\u003e\u003c\/span\u003e Shrimp Compatible with Caution\u003c\/span\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"body-wrap\"\u003e\u003cdiv class=\"prose\"\u003e\n    \u003cp\u003e\u003cstrong\u003eHarlequin Rasboras\u003c\/strong\u003e (\u003cem\u003eTrigonostigma heteromorpha\u003c\/em\u003e) have been a cornerstone of the aquarium hobby since they were introduced in the early 1900s, and they have held that position for good reason. The body is a warm copper-red with a metallic sheen, carrying a bold black triangular wedge that begins at the dorsal fin and tapers to the base of the tail. The genus name derives from the Greek word for \"differently shaped,\" referencing this distinctive body marking, and the common name comes from the resemblance of the black patch to the patterning on a harlequin's costume. Native to the blackwater streams and ponds of Thailand, Malaysia, Sumatra, and Singapore, they are hardy, adaptable, and long-lived at 5 to 8 years. In the wild they school in groups of over a hundred; in the aquarium a school of 8 to 10 is the practical minimum for natural behaviour. Note that the invoice designation \u003cem\u003eRasbora heteromorpha\u003c\/em\u003e is an older name; the current accepted classification is \u003cem\u003eTrigonostigma heteromorpha\u003c\/em\u003e.\u003c\/p\u003e\n    \u003cdiv class=\"stat-row\"\u003e\n      \u003cdiv class=\"stat-card\"\u003e\n\u003cspan class=\"stat-value\"\u003e5.0–7.5\u003c\/span\u003e\u003cspan class=\"stat-label\"\u003epH\u003c\/span\u003e\n\u003c\/div\u003e\n      \u003cdiv class=\"stat-card\"\u003e\n\u003cspan class=\"stat-value\"\u003e2–12\u003c\/span\u003e\u003cspan class=\"stat-label\"\u003eGH (dGH)\u003c\/span\u003e\n\u003c\/div\u003e\n      \u003cdiv class=\"stat-card\"\u003e\n\u003cspan class=\"stat-value\"\u003e72–80°F\u003c\/span\u003e\u003cspan class=\"stat-label\"\u003eTemperature\u003c\/span\u003e\n\u003c\/div\u003e\n      \u003cdiv class=\"stat-card\"\u003e\n\u003cspan class=\"stat-value\"\u003e2 in\u003c\/span\u003e\u003cspan class=\"stat-label\"\u003eMax Size\u003c\/span\u003e\n\u003c\/div\u003e\n    \u003c\/div\u003e\n    \n    \u003cspan class=\"section-label\"\u003eAppearance \u0026amp; Schooling\u003c\/span\u003e\n    \u003ch2\u003eThe Black Triangle\u003c\/h2\u003e\n    \u003cdiv class=\"bullet-list\"\u003e\n      \u003cspan class=\"bl-item\"\u003e\u003cstrong\u003eCopper-red metallic body with a bold black triangular wedge from dorsal fin to tail base.\u003c\/strong\u003e The black marking is the species' signature and is larger and more sharply triangular than the similar markings on the related Lambchop Rasbora (\u003cem\u003eTrigonostigma espei\u003c\/em\u003e) and Hengel's Rasbora (\u003cem\u003eT. hengeli\u003c\/em\u003e). The copper-red base has a genuine metallic quality that catches light as the school moves. The fins carry subtle red lining that adds warmth to the overall colouration.\u003c\/span\u003e\n      \u003cspan class=\"bl-item\"\u003e\u003cstrong\u003eColour is most vivid in soft, acidic, tannin-stained water with dim lighting.\u003c\/strong\u003e Harlequin Rasboras come from blackwater environments and show their best colour in conditions that replicate them. Soft acidic water with \u003ca href=\"\/es\/collections\/botanicals-parent\" title=\"Aquarium botanicals | leaves, pods \u0026amp; natural decor – superior shrimp \u0026amp; aquatics\" aria-label=\"Aquarium botanicals | leaves, pods \u0026amp; natural decor – superior shrimp \u0026amp; aquatics\"\u003eAlmond Leaves\u003c\/a\u003e or driftwood tannins, dark substrate, and subdued or plant-diffused lighting produces noticeably richer copper-red colouration than bright, hard, alkaline conditions.\u003c\/span\u003e\n      \u003cspan class=\"bl-item\"\u003e\u003cstrong\u003eSchool of 8 to 10 minimum, larger groups strongly preferred.\u003c\/strong\u003e In the wild this species moves in groups exceeding a hundred individuals. In the aquarium, groups below 8 result in nervous, scattered behaviour and faded colour. A school of 12 or more produces confident, cohesive schooling in the upper and middle water column and is where the species genuinely shines.\u003c\/span\u003e\n      \u003cspan class=\"bl-item\"\u003e\u003cstrong\u003eLong-lived at 5 to 8 years with good care.\u003c\/strong\u003e Harlequin Rasboras are notably long-lived for a small schooling fish, with most individuals reaching about 6 years and well-cared-for specimens hitting the upper end of that range. This makes a school a genuine multi-year investment rather than a short-term addition.\u003c\/span\u003e\n      \u003cspan class=\"bl-item\"\u003e\u003cstrong\u003eRequires a fully cycled, stable tank. Sensitive to water chemistry changes.\u003c\/strong\u003e While hardy once established, Harlequin Rasboras should only be added to tanks that have completed the nitrogen cycle. They are sensitive to ammonia, nitrite, and sudden parameter swings, and require adequate dissolved oxygen and consistent water quality.\u003c\/span\u003e\n    \u003c\/div\u003e\n    \u003cspan class=\"section-label\"\u003eShrimp Compatibility\u003c\/span\u003e\n    \u003ch2\u003eLarger Than the Nano Species\u003c\/h2\u003e\n    \u003cdiv class=\"bullet-list\"\u003e\n      \u003cspan class=\"bl-item\"\u003e\u003cstrong\u003eAdult Neocaridina shrimp are generally safe. Shrimplets are at meaningful risk.\u003c\/strong\u003e At 2 inches, Harlequin Rasboras are noticeably larger than the nano species like Chili Rasboras and Blue-Eyes, with a correspondingly larger mouth. Adult shrimp at full size are safe, but shrimplets and small juveniles will be consumed opportunistically. Dense planting with \u003ca href=\"\/es\/collections\/aquatic-plants-parent\" title=\"Aquatic plants for freshwater tanks | vibrant \u0026amp; healthy ecosystems – superior shrimp \u0026amp; aquatics\" aria-label=\"Aquatic plants for freshwater tanks | vibrant \u0026amp; healthy ecosystems – superior shrimp \u0026amp; aquatics\"\u003eJava Moss\u003c\/a\u003e and \u003ca href=\"\/es\/collections\/aquatic-plants-parent\" title=\"Aquatic plants for freshwater tanks | vibrant \u0026amp; healthy ecosystems – superior shrimp \u0026amp; aquatics\" aria-label=\"Aquatic plants for freshwater tanks | vibrant \u0026amp; healthy ecosystems – superior shrimp \u0026amp; aquatics\"\u003eSubwassertang\u003c\/a\u003e is necessary to maintain a breeding shrimp colony alongside a Harlequin school, and colony growth will be slower than in a fish-free tank.\u003c\/span\u003e\n      \u003cspan class=\"bl-item\"\u003e\u003cstrong\u003eParameter overlap works well with soft-water Neocaridina and Caridina setups.\u003c\/strong\u003e At pH 5.0 to 7.5 and soft to moderately soft water, Harlequin Rasboras suit both soft Neocaridina tanks and Caridina blackwater setups. The blackwater aesthetic that brings out their best colour is the same aesthetic that suits Caridina shrimp.\u003c\/span\u003e\n      \u003cspan class=\"bl-item\"\u003e\u003cstrong\u003eUpper and mid-water schooling reduces substrate-level interaction with shrimp.\u003c\/strong\u003e Harlequins occupy the top and middle of the water column, leaving the substrate and hardscape to the shrimp. The vertical separation reduces but does not eliminate predation pressure on shrimplets.\u003c\/span\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"tip-box\"\u003e\n\u003cspan class=\"tip-label\"\u003eKeeper's Note\u003c\/span\u003e\u003cp\u003eA school of 12 Harlequin Rasboras in a blackwater planted tank with Almond Leaves, dark substrate, and dim plant-diffused lighting is one of the most classically beautiful freshwater displays in the hobby, and it has been for a hundred years. The copper-red bodies with their black wedges moving in formation through tannin-stained water is the kind of tank that made people fall in love with the hobby in the first place. If you are keeping shrimp alongside them, plant heavily and expect a slower-growing colony in exchange for the display.\u003c\/p\u003e\n\u003c\/div\u003e\n    \u003ca href=\"\/es\/collections\/freshwater-fish-parent\" class=\"cta-block\" title=\"🐠 browse more freshwater fishbrowse our full freshwater fish collection. →\" aria-label=\"🐠 browse more freshwater fishbrowse our full freshwater fish collection. →\"\u003e\u003cspan class=\"cta-icon\"\u003e🐠\u003c\/span\u003e\u003cdiv class=\"cta-text\"\u003e\n\u003cstrong\u003eBrowse more freshwater fish\u003c\/strong\u003e\u003cp\u003eBrowse our full \u003cspan style=\"color:#F40909;font-weight:500;\"\u003eFreshwater Fish collection\u003c\/span\u003e.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cspan style=\"color:rgba(255,255,255,0.4);font-size:1.4rem;\"\u003e→\u003c\/span\u003e\u003c\/a\u003e\n    \u003cdiv class=\"policy-bar\"\u003e\n      \u003cspan\u003eBefore placing your order, please review our\u003c\/span\u003e\n      \u003ca href=\"\/es\/pages\/doa-policy\" title=\"Live arrival guarantee | superior shrimp \u0026amp; aquatics\" aria-label=\"Live arrival guarantee | superior shrimp \u0026amp; aquatics\"\u003eDOA Policy\u003c\/a\u003e\n      \u003ca href=\"\/es\/pages\/shipping-info-practices\" title=\"Shipping policies, info \u0026amp; practices – superior shrimp \u0026amp; aquatics\" aria-label=\"Shipping policies, info \u0026amp; practices – superior shrimp \u0026amp; aquatics\"\u003eShipping Info\u003c\/a\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/body\u003e","brand":"Superior Shrimp \u0026 Aquatics","offers":[{"title":"1","offer_id":45166933344464,"sku":null,"price":4.0,"currency_code":"USD","in_stock":true},{"title":"3","offer_id":45166933377232,"sku":null,"price":12.0,"currency_code":"USD","in_stock":true},{"title":"6","offer_id":45166933410000,"sku":null,"price":24.0,"currency_code":"USD","in_stock":true},{"title":"12","offer_id":45166933442768,"sku":null,"price":48.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0639\/2895\/9184\/files\/harlequin-rasbora-trigonostigma-heteromorpha-slender-transparent-128.webp?v=1789231475","url":"https:\/\/www.superiorshrimpaquatics.com\/es\/products\/harlequin-rasbora-trigonostigma-heteromorpha","provider":"Superior Shrimp \u0026 Aquatics","version":"1.0","type":"link"}