ม้าน้ำ (อังกฤษ: Seahorse) เป็นปลากระดูกแข็งที่อาศัยอยู่ในทะเลจำพวกหนึ่ง จัดอยู่ในวงศ์ย่อย Hippocampinae (ซึ่งมีอยู่ 2 สกุล คือหนึ่งสกุลนั้นคือ ปลาจิ้มฟันจระเข้สัน ที่อยู่ในสกุล Histiogamphelus มีรูปร่างคล้ายปลาจิ้มฟันจระเข้ผสมกับม้าน้ำ) ในวงศ์ Syngnathidae อันเป็นวงศ์เดียวกับปลาจิ้มฟันจระเข้และมังกรทะเล ในอันดับ Syngnathiformes

สำหรับม้าน้ำนั้นจะมีอยู่เพียงสกุลเดียว คือ Hippocampus (กรีก: ιππος, hippos = ม้า, καμπος, kampos = สัตว์ประหลาดทะเล)

Seahorses are fish shaped manner different from other kinds of fish , obviously that is encapsulated into the bone or bone armor scales outside agents . Instead of the tail fins for swimming to the other species. Back with a tail like a reptile. There are just so about themselves with algae or coral in the water. The pectoral fins and a straight waist and put another one fin to fin waving a blow by blow of the second wave is blowing at a speed of about 20 to 30 times per second. To move slowly , which is usually the Falcons tend to swim in the up - down . More to come forward - backward, like the other species. Holding a fish that swim slowest in the world. The swim is 0.06 miles per hour [ 1 ] Pipe organ held similar length no jaw. Towards the end of the opening . Used for suction feeding. Species , plankton and small fish can also modify the color of the body to the various environments in order to disguise [ 2 ] .

Falcons , like other fish in the same family as the male is pregnant . The organ at the Brewery baggy belly . Used for collecting and hatching eggs . When the breeding season, the male seahorse will modify the color of the body to attract the female seahorse . Then the male will embrace the female tail and belly bend opposite the stomach together. Females lay eggs into the abdomen of the male condom . The male seahorse will release semen into the mix with the eggs hatch and the larvae inside the pouch . It takes about two weeks of hatching eggs between 100-200 eggs most 1,500 eggs for each species.

Birth father on falcons will squeeze the abdominal muscles and throws the ball all Falcons . The left ventricular . The Falcons have a single behavior throughout life , is said to live in a single match . Should either party fail Dating is not new [ 3 ] .