A black Lab is a Labrador Retriever in the breed's original and most familiar color, not a separate breed. Labs descend from the St. John's water dogs of Newfoundland and were refined in Britain as gun dogs, which explains the broad head, otter tail, athletic build and dense, water-resistant double coat. Some have a small white spot on the chest, and the muzzle grays with age.
Color doesn't change personality. Most black Labs are friendly, eager to please and motivated by food, though field-bred dogs tend to be leaner and more driven than show-bred ones. In San Juan, that thick coat sheds year-round and holds heat, so plan on regular brushing and plenty of shade. Labs mature slowly, so a bouncy adolescence is normal and consistent training pays off.