Sexual dimorphism in fishes is an important biological aspect, which helps distinguish males and females based on various primary and secondary sexual characteristics. Based on sexual dimorphic characteristics fishes can be categorized as monomorphic, temporary dimorphic and permanent dimorphic. These characters can be either persistent or non-persistent types in fishes. Sexual dimorphism also can be determined using biometric characteristics as well. In fish, males typically display more conspicuous sexual characteristics compared to females, including the development of vibrant colouration, nuptial tubercles, or the formation of accessory organs. Sexual dimorphism is a significant trait helpful in categorizing and classifying fish species more accurately. It also has significant implications for commercial fisheries, which can aid in catch from the wild. This also can contribute to understanding the intricacies of aquatic ecosystems but also underscores the practical applications of studying sexual dimorphism in the context of sustainable fisheries management.

Sexual Dimorphism in Commercially Important Fish Species in India: A Review

Background: This study aims to unravel the genetic intricacies regulating the reproductive prolificacy of Tibetan sheep, an indigenous breed prominently found in the Qinghai-Tibet Plateau.&nbsp; 
 
Methods: We employed meticulous sequencing and analytical strategies to discern the differential expressions of long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs) in the ovarian tissues of ewes with varying lambing numbers.&nbsp; 
 
Result: In our study, we identified 817 genes with differential expression in twin-bearing ewes compared to those bearing single lambs. This group comprised 495 upregulated and 322 downregulated genes, featuring key candidates like COL1A1, COL1A2, BMPRIB, GDF9, BMP15 and TGFB2. Furthermore, we discovered a notable difference in the expression of long non-coding RNAs (lncRNAs) in ewes birthing twins as opposed to singles, with 210 differentially expressed lncRNAs identified, including 91 upregulated and 119 downregulated. Key genes and lncRNAs associated with reproductive efficiency were identified, contributing valuable insights into the underlying molecular mechanisms and offering a robust foundation for enhancing breeding strategies and overall livestock productivity.

Sexual Dimorphism in Commercially Important Fish Species in India: A Review

Elucidating the Genetic Regulation of Reproductive Prolificacy in Tibetan Sheep Through Ovarian Tissue Sequencing