一头搁浅瑞氏海豚的病理解剖和死因分析

瑞氏海豚在我国大陆沿海搁浅的案例相对较少。2019年7月10日，一头活体瑞氏海豚搁浅于广东省湛江市徐闻县石马角海域，半小时左右死亡。本文描述了该海豚的外部形态特征和骨骼系统，并通过解剖对其死因进行了分析。该瑞氏海豚为成年雌性，体长252.0 cm，体重约130.0 kg；体型消瘦，皮下脂肪层菲薄，体表无明显可致死外伤。头骨长45.6 cm，脊椎式为C7+T12+L23+Ca24=66，肋骨12对，V形骨19枚。解剖发现，该海豚的呼吸道和消化道中均存在大量泥沙；前胃内有两只长度超过30 cm的橡胶手套，胃和肠中几乎没有食糜和粪便。推测该瑞氏海豚可能因误食橡胶手套造成胃部阻塞而无法正常进食和消化，导致脂肪层过度消耗，体力不支而搁浅；在搁浅过程中可能因挣扎导致呼吸道进入大量泥沙引起呼吸不畅，最终死亡。当前难降解的海洋垃圾对海洋哺乳动物，包括以头足类为食的鲸类动物所产生的直接威胁已不容忽视。

Pathological anatomy and death cause of a stranded Risso’s dolphin (Grampus griseus)

Strandings of Risso’s dolphins(Grampus griseus) on the coastal areas of Chinese mainland are relatively scarce. On July 10th 2019, a live Risso’s dolphin stranded at Shimajiao waters in Xuwen, Zhanjiang City, Guangdong Province and died in a half hour. This paper reports the external morphological characteristics, skeletal measurements, necropsy results, and death cause of this stranded Risso’s dolphin. The dolphin was an adult female with a body length of 252.0 cm and a body weight of about 130.0 kg. Its body condition was poor, with little subcutaneous blubber, but external examination revealed no apparent fatal traumas. The dolphin’s skull was 45.6 cm in length; its vertebra arrangement was C7+T12+L23+Ca24=66, with 12 pairs of ribs and 19 V-bones. Large amounts of sand were found in the respiratory and digestive tracts; Furthermore, two rubber gloves (exceeding 30 cm in size) were present in the forestomach, and there were almost no chyme or feces in the stomachs and intestines, respectively. We infer that the dolphin may not have been able to eat and digest properly due to the stomach functional obstruction caused by the gloves, resulting in excessive depletion of the subcutaneous fat layer, which eventually led to the live stranding of the weakened animal; While stranded, sand entered the respiratory tracts resulting in inadequate breathing and finally death. Our results confirm that the ingestion of marine debris is an immediate threat to marine mammals, especially to cetaceans which mainly prey on cephalopods, and thus at present marine pollution caused by hard degradable waste cannot be ignored anymore.