Re-sighting of a Pantropical Spotted Dolphin (“Ji Ciyuan”) in Greater Bay Area, China ~ Aquatic Mammals Blog

On the morning of March 14th, 2019, a ship docked at Yantian Port during a routine safety inspection by law enforcement officers of the Shenzhen Maritime Safety Administration from Dapeng Bay. They accidentally found a dolphin swimming in the nearby water.

Witnessing Video 1

It is not the first time that dolphins have appeared in Yantian Port. There have been reported in the previous news, but they are all near the beacon lights, with a certain distance from the shore. The dolphin approaches the port side from time to time, and bursts near the water surface. The spray from the breathing hole was also visible during the short-range bursting.

The captured video is only ten seconds, the shot is not very clear, and it is impossible to judge whether it is a Spinner dolphin or the Pantropical spotted dolphin. If it is the latter, it is a new record in cetaceans’ sighting in the Greater Bay Area. If it is the former, it may be our old friend. I have met it twice on the seafloor.

The first time it was spotted on September 12^th, 2017. A boat owner called me. He found a dolphin in the waters near the Daya bay area. It has been staying under a beacon light for three days. I went to the sighted site and filmed underwater. After nearly an hour, this is the photo taken at that time.

A young male dolphin spotted with few spots on his body and clear spots on his snout. This is an important feature for identifying individuals. The second time was on June 25^th, 2018. The boat owner sent me a video of a dolphin cruising near the beacon light somewhere in Dapeng Bay. He told me that it was here three days ago. Surrounded by the navigation lights and refused to leave.

Witnessing Video 2 (Source: Boatman Bai Xiaoci)

After hearing the news, I quickly brought my underwater camera and rushed to the scene. Compared with last year, this time in the sea outside Xiaomeisha, I had ampler space to take underwater videos and pictures. The dolphin we saw this time was also a Pantropical Spotted dolphin. Is it the one from last year? Ji Ciyuan came again? We need to carefully compare the physical characteristics of the captured video to determine. After comparing the characteristics of the pictures, I discovered that this is the same dolphin (Ji Ciyuan).

Witnessing Video 3

Is the dolphin that appeared in the video for the third time the same as the previous two sightings? Because no spots were photographed, it is still uncertain. If it is the same, I can be even more sure that the dolphin I named "Ji Ciyuan" does live in Tai O Bay for a long time, and it is becoming more and more fearless. This time it appeared near the shore. If it is not the same, it means that the spotted dolphin has a small population in Tai O Bay. Pantropical Spotted dolphin (Stenella attenuate) is the third marine mammal species recorded in the Shenzhen and Hong Kong waters beside the Chinese white dolphin (Sousa Chinensis) and the Finless Porpoise (Neophocaena phocaenoides). It is more worthwhile to invest resources for conservation and protection.

**The Genus Stenella (Oceanic dolphins)**

IUCN Red List Protection Level LC (Low Risk)

There are five species in the genus Stenella. Namely, Short-snouted spinner dolphin (Stenella clymene), Stripped dolphin (Stenella coeruleoalba), Spinner dolphin (Stenella longirostris), Pantropical spotted dolphin (Stenella attenuate), and Atlantic spotted dolphin (Stenella frontalis). The first four species are distributed in China. The characteristic feature of this genus is that the adult body length is within 275 cm. The dorsal fin is bent backward, with no light-colored area in the middle. The beak is long and narrow, and the length is more than 2.2 times the width. The upper and lower jaws have 34 to 56 small, pointed teeth on each side. There are 68 to 81 vertebrae, and the first two cervical vertebrae are healed. The back is dark blue or black, and most of the sides have a dark band, which is different from the body color of the Chinese white dolphin and the White-beaked dolphin.

About Admin MC3

This is dummy text. It is not meant to be read. Accordingly, it is difficult to figure out when to end it. But then, this is dummy text. It is not meant to be read. Period.