মাছে উপস্থিত এক বা একাধিক সংখ্যক পাখনা যারা হুবহু একই রকম নয় তাদেরকে মধ্যগ পাখনা বলে (বিজোড় পাখনা নামেই অধিক পরিচিত)। যেমন- পৃষ্ঠ পাখনা, পুচ্ছ পাখনা, পায়ু পাখনা ইত্যাদি। এই পাখনাগুলো দেহের মাঝ বরাবর অবস্থান করায় এগুলোর এমন নামকরণ করা
Metamerism
Metamerism (also known segmentation) is the arrangement of fundamentally similar (more or less) body segments (metameres) along the longitudinal axis of an animal. Mainly two types: External metamerism (body segmentation occurs externally) and internal metamerism (body segmentation occurs only internally).
Monoploid
Monoploid means having only one set of basic or unique chromosomes. These include the vast majority of prokaryotes. The symbol of monoploid is “x” On the other hand, haploid means having half of the total number of unique chromosomes in
Migration
Migration is the cyclic movement of all or large portion of an animal population from own habitat to another place (one or more) for getting favorable environment, feeding, breeding, etc. The word migration is formed from Latin word migratus (past
Mesoderm
Mesoderm is one of three germ layers of triploblastic animal embryo, lying between the ectoderm and endoderm. Gr. mesos means middle and derma means skin The muscles, bones, cartilages, fibrous connective tissues, dermis, gonads, kidney, urinary ducts, cortex, spleen and