How do Dumbo rats differ from Rex rats? - briefly
Dumbo rats have large, low‑set ears that fold forward, while Rex rats feature a plush, curly coat with standard‑shaped ears. The strains differ in breeding emphasis: Dumbo selection targets ear morphology, whereas Rex selection focuses on coat texture.
How do Dumbo rats differ from Rex rats? - in detail
Dumbo rats possess exceptionally large, low‑set ears that extend horizontally beyond the head, while Rex rats have standard‑sized ears positioned higher on the skull. The ear morphology results from a specific mutation affecting cartilage development, giving Dumbo rats a distinctive silhouette.
Coat texture distinguishes the two strains. Rex rats exhibit a plush, velvety fur caused by a separate mutation that reduces guard hairs, creating a uniform, short pile. In contrast, Dumbo rats retain the typical smooth coat of standard laboratory rats, lacking the dense undercoat characteristic of the Rex variety.
Genetic background differs as well. The Dumbo trait is linked to an autosomal recessive allele on chromosome 4, whereas the Rex phenotype originates from an autosomal recessive gene on chromosome 2. Breeding two carriers of each trait produces litters with predictable Mendelian ratios, allowing breeders to forecast the occurrence of each phenotype.
Health considerations vary. The enlarged ears of Dumbo rats predispose them to otitis externa and require regular cleaning to prevent debris accumulation. Rex rats, with their dense fur, are more prone to skin infections if grooming is insufficient, and their coat may retain moisture, increasing the risk of fungal growth.
Behavioral tendencies show minor divergence. Both strains display typical Rattus norvegicus temperament, yet anecdotal observations suggest Dumbo rats may exhibit increased sociability due to heightened tactile stimulation from their ears, while Rex rats often demonstrate a slightly calmer demeanor, possibly related to their reduced sensory input from the coat.
Key distinctions can be summarized:
- Ear size and placement: large, low‑set (Dumbo) vs. normal, high‑set (Rex)
- Fur texture: standard smooth coat (Dumbo) vs. plush, uniform pile (Rex)
- Genetic locus: chromosome 4 (Dumbo) vs. chromosome 2 (Rex)
- Common health issues: ear infections (Dumbo) vs. skin/fungal problems (Rex)
- Typical behavior: heightened sociability (Dumbo) vs. calmer disposition (Rex)
Understanding these differences informs breeding decisions, veterinary care, and selection for specific research or pet‑keeping purposes.