{"product_id":"peruvian-red-pencilfish-nannostomus-mortenthaleri","title":"Peruvian Red Pencilfish – Nannostomus mortenthaleri","description":"\u003cp\u003eThe Peruvian Red Pencilfish (Nannostomus mortenthaleri) is a premium nano freshwater fish known for its intense red coloration, slender body, and elegant top-dwelling behavior. This highly desirable pencilfish adds vivid color, graceful movement, and a refined look to planted aquariums and aquascaping displays.\u003c\/p\u003e\n\u003cp\u003ePeruvian Red Pencilfish are especially attractive in natural-style aquariums with live plants, driftwood, darker backgrounds, and calm tankmates. Their bold red color stands out beautifully against green plants, making them a favorite for aquarists who want a unique showpiece nano fish.\u003c\/p\u003e\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eIntense red coloration\u003c\/li\u003e\n\u003cli\u003ePremium nano pencilfish species\u003c\/li\u003e\n\u003cli\u003ePeaceful top-dwelling behavior\u003c\/li\u003e\n\u003cli\u003eExcellent for planted aquariums and aquascapes\u003c\/li\u003e\n\u003cli\u003eElegant movement and refined appearance\u003c\/li\u003e\n\u003cli\u003eBest kept in groups of 6 or more\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCare Guide\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eScientific Name:\u003c\/strong\u003e Nannostomus mortenthaleri\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCommon Name:\u003c\/strong\u003e Peruvian Red Pencilfish\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCare Level:\u003c\/strong\u003e Moderate\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTemperament:\u003c\/strong\u003e Peaceful; males may display toward each other\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAdult Size:\u003c\/strong\u003e Approximately 1.25–1.5 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSize at Sale:\u003c\/strong\u003e Approximately 0.75–1 inch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMinimum Tank Size:\u003c\/strong\u003e 15–20 gallons or larger recommended\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTank Level:\u003c\/strong\u003e Top to upper-middle\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWater Temperature:\u003c\/strong\u003e 74–80°F\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003epH Range:\u003c\/strong\u003e 5.5–7.0\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHardness:\u003c\/strong\u003e Soft water preferred\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDiet:\u003c\/strong\u003e Omnivore\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eWhy Choose Peruvian Red Pencilfish?\u003c\/h3\u003e\n\u003cp\u003ePeruvian Red Pencilfish are considered one of the most colorful and sought-after pencilfish species in the aquarium hobby. Their vivid red coloration and graceful swimming style make them a standout choice for planted tanks, nano aquariums, and high-end aquascapes.\u003c\/p\u003e\n\u003cp\u003eThey are peaceful and calm, but they do best in stable aquariums with gentle tankmates. A group of 6 or more helps reduce stress, encourages natural behavior, and creates a more attractive display.\u003c\/p\u003e\n\u003ch3\u003eIdeal Tank Setup\u003c\/h3\u003e\n\u003cp\u003ePeruvian Red Pencilfish do best in a mature, stable aquarium with live plants, floating plants, driftwood, and gentle filtration. Dark substrate, leaf litter, botanicals, and shaded areas can help create a natural environment while enhancing their red coloration.\u003c\/p\u003e\n\u003cp\u003eBecause they spend much of their time near the upper levels of the aquarium, a secure lid is recommended. Avoid strong current, aggressive tankmates, and overly active fish that may outcompete them for food.\u003c\/p\u003e\n\u003ch3\u003eCompatible Tankmates\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eEmber Tetras\u003c\/li\u003e\n\u003cli\u003eGreen Neon Tetras\u003c\/li\u003e\n\u003cli\u003eSmall peaceful rasboras\u003c\/li\u003e\n\u003cli\u003eOther peaceful pencilfish\u003c\/li\u003e\n\u003cli\u003ePygmy Corydoras\u003c\/li\u003e\n\u003cli\u003eOtocinclus\u003c\/li\u003e\n\u003cli\u003eShrimp with proper cover\u003c\/li\u003e\n\u003cli\u003eSmall peaceful snails\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eTankmates to Avoid\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eLarge or aggressive fish\u003c\/li\u003e\n\u003cli\u003eFast, boisterous fish that outcompete them for food\u003c\/li\u003e\n\u003cli\u003eFin-nipping species\u003c\/li\u003e\n\u003cli\u003ePredatory fish\u003c\/li\u003e\n\u003cli\u003eFish that require hard, alkaline water\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eDiet \u0026amp; Feeding\u003c\/h3\u003e\n\u003cp\u003ePeruvian Red Pencilfish have small mouths and should be offered small, appropriately sized foods. Feed quality micro pellets, fine flakes, crushed flakes, frozen baby brine shrimp, daphnia, cyclops, and small live foods when available.\u003c\/p\u003e\n\u003cp\u003eA varied diet helps support strong red coloration, activity, and overall condition. Feed small portions that the group can consume quickly.\u003c\/p\u003e\n\u003ch3\u003eCare Tips\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eKeep in groups of 6 or more\u003c\/li\u003e\n\u003cli\u003eUse a mature, stable aquarium\u003c\/li\u003e\n\u003cli\u003eProvide live plants, floating plants, and gentle cover\u003c\/li\u003e\n\u003cli\u003eMaintain soft, clean, stable water when possible\u003c\/li\u003e\n\u003cli\u003eUse darker substrate or backgrounds for best color contrast\u003c\/li\u003e\n\u003cli\u003eUse a secure lid since top-dwelling fish may jump\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eAre Peruvian Red Pencilfish good for planted tanks?\u003c\/strong\u003e\u003cbr\u003eYes. Peruvian Red Pencilfish are excellent for planted aquariums and aquascaping layouts, where their red coloration stands out against green plants and darker backgrounds.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow many Peruvian Red Pencilfish should I keep together?\u003c\/strong\u003e\u003cbr\u003eKeep at least 6 or more for best confidence, behavior, and reduced stress.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAre Peruvian Red Pencilfish aggressive?\u003c\/strong\u003e\u003cbr\u003eThey are peaceful overall, though males may display toward each other. Providing plants, space, and a proper group helps reduce stress.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat part of the tank do Peruvian Red Pencilfish use?\u003c\/strong\u003e\u003cbr\u003eThey mostly use the top to upper-middle portion of the aquarium.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow big do Peruvian Red Pencilfish get?\u003c\/strong\u003e\u003cbr\u003eThey typically reach approximately 1.25–1.5 inches as adults.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat do Peruvian Red Pencilfish eat?\u003c\/strong\u003e\u003cbr\u003eThey eat micro pellets, fine flakes, frozen baby brine shrimp, daphnia, cyclops, and other small foods.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAre these fish available for shipping?\u003c\/strong\u003e\u003cbr\u003eNo. Live fish are available for in-store purchase or local pickup only at Tropical Treasures Wyo in Cheyenne, Wyoming.\u003c\/p\u003e\n\u003ch3\u003eAvailable at Tropical Treasures Wyo\u003c\/h3\u003e\n\u003cp\u003ePeruvian Red Pencilfish are premium nano fish for planted aquariums, aquascapes, and calm freshwater community tanks. Visit Tropical Treasures Wyo in Cheyenne, Wyoming, to shop pencilfish, nano fish, freshwater fish, shrimp, snails, live aquarium plants, fish food, filtration supplies, and aquarium care products. Live livestock is available for in-store purchase or local pickup only.\u003c\/p\u003e","brand":"Tropical Treasures Wyo LLC","offers":[{"title":"Default Title","offer_id":51391750242517,"sku":null,"price":11.99,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0670\/4545\/8133\/files\/RedPencilfish.jpg?v=1756073153","url":"https:\/\/tropicaltreasureswyo.com\/products\/peruvian-red-pencilfish-nannostomus-mortenthaleri","provider":"Tropical Treasures Wyo LLC","version":"1.0","type":"link"}