Conjoined fetal twins in a harbor seal (Phoca vitulina)
This article describes the first known case of conjoined twins in a harbor seal. The case was documented in the Salish Sea region where harbor seals are often used as indicators of contaminant levels. However, researchers say their findings do not support that this anomaly was due to any common contaminants and hypothesize that the twinning was caused by disordered embryo migration and fusion.
Abstract
In July 2013, a stranded harbor seal (Phoca vitulina) died giving birth to conjoined fetuses. The twins were joined at the abdomen and thoracolumbar spine with the vertebral axis at 180°. The cause of this unique anomaly—a first for this species—was not identified.
Citation
Olson JK, Gaydos JK, McKlveen T, Poppenga R, Wicinas K, Anderson E, & Raverty S. 2015. Conjoined Fetal Twins in a Harbor Seal (Phoca vitulina). Jrnl of Wildlife Diseases, 52(1):173-176.
