生物名称：深湖掠食者（Deep Lake Predator）

等级：Turbidity current level（浊流级）

编号：SlO-1992-002

成年个体体长约25-35米，类似于蛇颈龙，体重预估15-20吨，体型呈扭流线型，躯干中段直径约4-5米，向头尾逐渐收窄。全身覆盖层叠的黑灰色厚皮，皮表布满不规则的深灰色褶皱，褶皱内暗藏角质棘刺长度5-10厘米，尖端呈倒钩状，被触碰或愤怒时会外翻突出。

头部占体长的1/6，呈楔形，吻部尖锐，上下颚可张开至120度，口中分布3排共60-80颗三棱形利齿，长15-20厘米，齿面布满锯齿，齿根与颌骨间有弹性韧带，可随猎物大小调整咬合角度。双眼位于头部顶端，能在完全黑暗中捕捉生物电信号；头顶内部有高度敏感的“水压感知器”，可探测1公里内的水流扰动。

躯体两侧无明显鳍肢，代之以6条带蹼的腕状附肢，长度约3-4米，最高游速可达40公里/小时；背部正中有一道贯穿头尾的帆状棘背。

体温恒定，能在0-15℃的冷水域中维持活动。皮肤下有海绵状气囊组织，可通过充气/放气调节浮力，使其能在深水区悬浮或快速上浮。最显著的超自然特征是其骨骼可发出低频声波（1-5赫兹），与深水压力波产生共振，既能震晕猎物，也能在水下形成“声波屏障”，干扰声呐探测。

顶级掠食者，食谱涵盖大型淡水鱼类、水生哺乳动物，如鹿、野牛等误入水域的陆生动物，甚至同类幼体。捕猎时会先通过水压感知器锁定目标，随后以高速冲撞将猎物击晕，通过锯齿状牙齿撕咬分食，进食时会将猎物拖入深水区，以避免被其他掠食者抢夺，单次进食量可达自身体重的10%。

白天潜伏于湖泊100-500米深的岩缝中，夜晚升至50-100米水层活动。擅长利用共振制造水流漩涡，将猎物卷入其中，再从漩涡中心发动突袭。对人类活动的声音（如马达声、船体震动）极为敏感，会将其判定为“入侵信号”，主动追踪并撞击船只，直至目标沉没。

独居生物，成年个体领地范围可达2-3平方公里，通过在水域中释放信息素标记边界。同类相遇时会发生激烈争斗。

繁殖期为每8年一次，仅在冬季湖面封冻时进行。雌性会在湖底岩缝中产卵，每窝1-2枚，雄性通过共振声波争夺交配权，获胜者会守护卵直至孵化（5个月）。幼体体长约3-4米，出生时即具备完整攻击能力，会在成年个体的领地边缘活动1年后离开，独立建立领地，寿命预估可达40-50年

SIO首次记录于1992年，因当地渔民目击事件和死亡事件，前只发现栖息于七个湖泊，其中有五个连同地下，真至海洋

Adult individuals are approximately 25 - 35 meters long, similar in form to a serpent, with an estimated weight of 15 - 20 tons. Their body is twisted - streamlined, with a mid - torso diameter of about 4 - 5 meters, tapering gradually toward the head and tail. The entire body is covered in overlapping, thick black - gray skin, which is dotted with irregular dark gray folds. Within these folds lie 5 - 10 - centimeter - long keratinous spines, hooked at the tips, that protrude when touched or when the creature is enraged.

The head makes up 1/6 of the body length and is wedge - shaped, with a sharp snout. The jaws can open to 120 degrees, and inside the mouth are 3 rows of 60 - 80 triangular, serrated teeth, each 15 - 20 centimeters long. Elastic ligaments connect the tooth roots to the jawbone, allowing the bite angle to adjust according to the prey’s size. The eyes are located on the top of the head and can detect bioelectrical signals in complete darkness; inside the skull, there is a highly sensitive “hydro - pressure sensor” capable of detecting water current disturbances within a 1 - kilometer radius.

There are no obvious fin - like limbs on either side of the body. Instead, there are six webbed, wrist - like appendages, each 3 - 4 meters long, enabling a maximum swimming speed of 40 kilometers per hour. A sail - like spiny ridge runs along the center of the back, from head to tail.

It has a constant body temperature and can remain active in cold waters ranging from 0–15°C. Beneath the skin is a spongy air - sac tissue that regulates buoyancy through inflation or deflation, allowing it to suspend in deep water or rise rapidly. Its most remarkable supernatural feature is that its bones emit low - frequency sound waves (1–5 Hz), which resonate with deep - water pressure waves. This can stun prey and also form an “acoustic barrier” underwater to interfere with sonar detection.

As a top predator, its diet includes large freshwater fish, aquatic mammals, terrestrial animals such as deer and wild cattle that stray into water, and even the young of its own species. When hunting, it first locks onto targets using the hydro - pressure sensor, then strikes at high speed to stun the prey, tearing it apart with its serrated teeth. While feeding, it drags the prey into deep water to avoid

being scavenged by other predators, and a single meal can reach 10% of its own body weight.

It lurks in rock crevices 100 - 500 meters deep in lakes during the day and rises to the 50 - 100 - meter water layer at night. Skilled at creating water vortices via resonance to draw prey in, it then launches ambushes from the vortex center. It is extremely sensitive to sounds of human activity (e.g., engine noise, hull vibrations), classifying them as "intrusion signals" and actively pursuing and ramming ships until they sink.

A solitary creature, an adult’s territory can span 2 - 3 square kilometers, marked by pheromones released into the water. Fierce battles erupt when conspecifics meet.

The breeding period occurs once every 8 years, only during winter when the lake surface freezes. Females lay 1 - 2 eggs in lake - bed rock crevices; males compete for mating rights via resonant sound waves, and the winner guards the eggs until hatching (5 months). Juveniles, around 3 - 4 meters long at birth, possess full attack capabilities. They remain on the edge of an adult’s territory for a year before leaving to establish their own, with an estimated lifespan of 40 - 50 years.

SIO first documented it in 1992 following local fishermen’s sightings and fatal incidents. Currently, it has only been found inhabiting seven lakes, five of which are connected to underground water systems, extending to the ocean.