Which body of water separates the Arabian peninsula from the Horn of Africa?
And the answer: Gulf of Aden.

Situated on the southern coast of Yemen, the Gulf of Aden connects the Red Sea with the Arabian Sea. The gulf is home to many animals, including whales, dolphins, tuna, and rock lobsters, and even serves as a breeding ground for sea turtles.
Named for the seaport Aden in southern Yemen, the Gulf of Aden is a deepwater basin that is home to a bursting array of marine life. It also provides an outlet to the west for Persian Gulf oil, making it a very popular shipping route. In recent years, however, this popularity has proved dangerous, as Somali pirates have taken advantage of the high traffic to hijack boats passing through the waters and hold them for ransom.
Aside from piracy, though, the Gulf of Aden is abound with wildlife. Though much shipping occurs in the strait, it boasts relatively low pollution levels as well as many varieties of fish and coral. The Gulf of Aden is strongly influenced by the upwelling of cool, nutrient-rich waters during the southwest and northeast monsoons and is characterized by a prevailing high-energy climate that is perfect for coral to flourish.
Additionally, there are extensive mangrove stands in the Red Sea and Gulf of Aden. Mangroves are an extremely important form of coastal vegetation, as their extensive root systems stabilize sediments and protect the coastline as well as provide shelter for an array of marine animals and birds.
Learn more about the gulf here.
