Historical biogeography of the Mugil cephalus species complex and its rapid global colonization.

Our understanding of speciation processes in marine environments remains very limited and the role of different reproductive barriers are still debated. While physical barriers were considered important drivers causing reproductive isolation, recent studies highlight the importance of climatic and hydrological changes creating unsuitable habitat conditions as factors promoting population isolation. Although speciation in marine fish has been investigated from different perspectives, these studies often have a limited geographical extant.

Monocephalus dipygus in a 4-month-old mixed-breed puppy: clinical, radiographic, ultrasonographic, karyotyping and surgical intervention.

Congenital anomalies are rare in veterinary medicine, and their aetiology, development, clinical presentation, and management remain poorly understood. This study documents a rare case of multiple congenital anomalies occurring simultaneously in a single individual. We present a comprehensive analysis of a 4-month-old mixed-breed puppy diagnosed with caudal duplication (monocephalus dipygus), integrating clinical, radiographic, ultrasonographic, cytogenetic findings, and surgical intervention.

Integrating Genomic and Chromosomal Data: A Cytogenetic Study of (Loricariidae: Hypostominae) with Characterization of a ZZ/ZW Sex Chromosome System.

The plecos (Loricariidae) fish represent a great model for cytogenetic investigations due to their variety of karyotypes, including diploid and polyploid genomes, and different types of sex chromosomes. In this study we investigate a rare loricariid endemic to Ecuador, integrating cytogenetic methods with specimens' molecular identification by mtDNA, to describe the the species karyotype. We aim to verify whether sex chromosomes are cytologically identifiable and if they are associated with the accumulation of repetitive sequences present in other species of the family.

First cytogenetic analysis of (Günther, 1860) by conventional and molecular methods with comments on the karyotypic evolution in Prochilodontidae.

We used conventional cytogenetic techniques (Giemsa, C-banding, Ag-NOR), and fluorescent hybridization (FISH) with 5S and 18S rDNA probes to investigate the karyotype and cytogenetic characteristics of (Günther, 1860) from Ecuador. The specimens studied have a karyotype with 2n=54 biarmed chromosomes (32 M + 22 SM) and C-positive heterochromatin located on the centromeric, pericentromeric, interstitial, and terminal regions of some chromosomes. The nucleolus organizer regions occurred terminally on the long arm of chromosome pair 2.