Monogamous pairs can often be found coiled together or within close proximity to one another (Clayton, 2003). Pairs communicate daily during male pregnancy to reinforce their relationship. (John G. Shedd Aquarium, 2004) The first few stages of the mating ritual are repeated, which include changing body color patterns, dancing, and making clicking sounds. This implies they they communicate through visual cues, sounds, and through touch. Seahorses also perceive their environment with these same senses.
Spotted seahorses are able to maximize their perception of potential prey and predators by moving their eyes independently of each other ("Project Seahorse", 2003).
Communication Channels: visual ; tactile ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Humans are the primary predators of H. kuda because of their large economic importance ("Project Seahorses", 2003). There are few natural predators of adult seahorses due to their unpalatable bony-plated bodies and their ability to avoid predation through camouflage. However, they have been found in the stomachs of loggerhead sea turtles, tunas, and dorados. Skates, rays, and crabs have also been observed to prey on seahorses.
Known Predators:
Anti-predator Adaptations: cryptic
Originally, ancient Greek poets used the Greek word Hippocampus to describe a half-horse, half-fish mythical god (hippos meaning horse and campus meaning sea monster) (Lally and Hough, 1999). This description poignantly describes their horse-like head positioned 90 degrees from its upright, armor-plated body, curved trunk, and prehensile tail ("Project Seahorse", 2003). Spotted seahorses can have an all black, grainy textured body pattern or a creamy, pale yellow body spotted with large, dark circles. These colors and patterns can be changed temporarily to match their immediate surroundings and act as a camouflage to avoid predators (Lourie et al., 1999).
Spotted seahorses are morphologically conservative and lack typical physical features of fishes such as pelvic and caudal fins, teeth, and a stomach (Lourie et al., 1999; "Project Seahorse", 2003). They also lack scales, having a layer of skin stretched over a series of bony plates instead which are visible as rings around the trunk ("Project Seahorse", 2003). These visible rings are useful in identifying various Hippocampus species.
Hippocampus barbouri can be distinguished from other seahorses by the presence of low, rounded bumps instead of the typical spines found along the body ("Project Seahorse", 2003). Spotted seahorses have a characteristically thick snout and deep head (Lourie et al., 2004). On either side of the deep head are eyes that can move independently, allowing them to maximize the search range when hunting for prey ("Project Seahorse", 2003). An adult H. kuda male can be distinguished from a female by the presence of a brooding pouch on his belly.
Seahorse lengths are measured by recording the distance from the tip of the tail to the top of the coronet, a cup-like depression found on top of the head. Adult lengths of H. kuda typically range between 7.0 and 17.0 cm (Capuli, Torres, and Froese, 2004). Adult weights, on the other hand, vary with the reproductive stages of both males and females ("Project Seahorse", 2003).
Range length: 7 to 17 cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: sexes shaped differently
The natural lifespan of H. kuda and its relatives are virtually unknown ("Project Seahorse", 2003). Lab and aquatic observations estimate 3 to 5 years for larger seahorse species and 1 year for smaller species.
Typical lifespan
Status: captivity: 1 to 5 years.
Generally, H. kuda inhabit shallow inshore areas with an average depth of 0 to 8 m, but they have also been found at a maximum depth of 55 m (Lourie et al., 2004). They can be found in mangroves, coastal seagrass beds, estuaries, coastal bays and lagoons, harbors, sandy sediments in rocky littoral zones, and rivers with brackish waters (Lourie et al., 2004; Job et al., 2002). Spotted seahorses have also been found attached to drifting Sargasssum as far as 20 km from shore (Foster et al., 2003).
Range depth: 0 to 55 m.
Average depth: 0-8 m.
Habitat Regions: tropical ; saltwater or marine
Aquatic Biomes: reef ; coastal
Other Habitat Features: estuarine
Hippocampus kuda is strictly a marine species, widely distributed throughout the Indo-Pacific region, from the Indian Ocean to the northwestern, western central, and eastern central areas of the Pacific Ocean ("Project Seahorse", 2003; Foster et al., 2003). Approximately 23 countries have confirmed the native presence of H. kuda, ranging from Australia to China (Lourie et al., 2004). Because spotted seahorses are popular ornamental aquarium fish, their captive distribution has become global (Lally and Hough, 1999).
Biogeographic Regions: indian ocean (Native ); pacific ocean (Native )
Spotted seahorses are ambush predators and thrive only on live, moving food (Lally and Hough, 1999; “Project Seahorse”, 2003). They have large appetites and feed mainly on zooplankton, small crustaceans, and larval fishes. Because they are poor swimmers, H. kuda utilize their thick snouts and specialized jaws to suck in their prey (“Project Seahorse”, 2003).
Animal Foods: fish; aquatic or marine worms; aquatic crustaceans; zooplankton
Primary Diet: carnivore (Eats non-insect arthropods); planktivore
Seahorses in general can act as food items for many larger fish, crustaceans, and water birds ("Project Seahorse", 2003). Adult seahorses themselves are voracious predators and will suck and swallow any animal that will fit in their mouths.
Spotted seahorses are the most valuable species in the traditional Chinese medicine trade (TCM) due to their large size, smooth texture, and pale complexion when dried (Project Seahorse et al, 2003). According to traders, TCM books, and recent pharmacological studies, seahorses can regulate urinogenital, reproductive, nervous, endocrine, and immune systems as well as mimic certain hormones related to aging, tumor development, and fatigue (Zhang et al., 2003). None of these uses, however, have been tested. The global consumption of seahorses for medicinal purposes during the year 2001 alone has been estimated at 25 million seahorses or 70 metric tones (“Project Seahorse”, 2003).
Spotted seahorses are very popular among aquatic collectors as a favorite aquarium fish (Lally and Hough, 1999). Over 51 nations and territories are involved in buying and selling H. kuda and its relatives (Job et al., 2002). The largest known exporters of seahorses are Thailand, Vietnam, India, and the Philippines, and the bulk of seahorses are fished from the Indo-Pacific region (Xu et al., 2003).
Seahorses are fascinating to many people and diving trips to see seahorses, as well as other fish, are important in marine ecotourism.
Positive Impacts: pet trade ; body parts are source of valuable material; ecotourism
Spotted seahorses have no negative effects on humans.
Eggs are fertilized by the male and become embedded in the pouch wall as they are deposited into the brooding pouch by the female through the ovipositor (“Project Seahorse”, 2003). The male may carry between 20 to 1000 eggs in its pouch (Tchi Mi, Kornienko, and Drozdov, 1996). Although fertilized eggs contain a small amount of yolk, they undergo typical teleost egg cleavage and developmental processes, which lasts for approximately 20 to 28 days. Larval development stops one week prior to the time at which they are released into the open waters.
The timing of labor in males varies depending upon species, water temperature, monsoon patterns, and lunar cycles ("Project Seahorse", 2003). However, most males go into labor at night during a full moon. Males engage in vigorous pumping and thrusting motions for several hours to release the young. Juvenile seahorses emerge from the pouch as independent, miniature adults. The average length of H. kuda at birth is 7 mm.
In general juvenile seahorses can be distinguished from their adult counterparts by differences in body proportions (Lourie et al., 2004). Young seahorses have larger heads, slimmer, spinier bodies, and higher coronets. In captivity, H. kuda have been observed to reach full maturity in 14 weeks, growing at a rate of .9 to 1.53 mm per day (Job et al.,2002).
Spotted seahorses are listed as vulnerable under the World Conservation Union’s IUCN Red List and are on the CITES Appendix II (Lally and Hough, 1999). Population numbers of H. kuda in the wild are unknown but scientists, conservationists, and traders agree that populations have declined by at least 30% due to habitat destruction, pollution, bycatch, trades in traditional Chinese medicine, curios, and aquaria (Lally and Hough, 1999; Project Seahorse et al, 2003). There is little legal oversight or regulation on trading, and few countries require permits (Lally and Hough, 1999).
Scientists predict further declines in H. kuda population without immediate intervention (Lally and Hough, 1999). Implementing effective conservation methods has been hampered by confusion over H. kuda taxonomy, which has been driven by the difficulty in morphologically distinguishing them from their relatives, their ability to camouflage, current lack of descriptions, and unestablished, independent naming designations (Lourie et al., 1999). Taxonomic definitions must be established first before researchers can confidently understand the biology, ecology, and relative abundance of spotted seahorses.
Seahorse farming is currently being developed as an alternative strategy to conserve native seahorse populations while helping fishers to continue earning a sustainable income (Job et al., 2002). Initial research of H. kuda’s ability to grow and survive appears very promising, but further research is needed to determine whether aquaculturing of the spotted seahorse on a more larger scale effectively meets the high market demand while preventing further depletion of native populations.
US Federal List: no special status
CITES: appendix ii
IUCN Red List of Threatened Species: no special status
Both wild and cultured H. kuda are susceptible to Costia disease infections, a protozoan parasite (Capuli, Torres, and Froese, 2004).
Spotted seahorses maintain a faithful association with only one partner (Clayton, 2003). A new mate is sought only when a partner dies. Seahorses in general have a complex mating system, which is characterized by a unique courtship ritual (John G. Shedd Aquarium, 2004). The male begins by changing its color patterns as it dances around the female. It also produces clicking sounds with its coronet. The pair proceeds with the ritual by entwining their tails together and floating across the ocean floor. Eventually the male and female face each other belly-to-belly at which time the female places her eggs into the male’s brooding pouch with her ovipositor. This courtship ritual is modified and repeated daily even after the male has become pregnant. Each morning the pair comes together to dance, change colors, and entwine tails.
Mating System: monogamous
The age at which female and male H. kuda reach sexual maturity is unknown ("Project Seahorse", 2003). However the presence of a brooding pouch on the male - the site where the male carries the fertilized eggs- signifies male sexual maturity. Breeding occurs year round (John G. Shedd Aquarium, 2004). A female may return to lay a new batch of eggs in her partner's pouch the same day that juveniles are released. Gestation generally occurs within 20 to 28 days (Lourie et al., 2004). The maximum reported brood size is 1405, but a brooding pouch may contain anywhere from 20 to 1000 fertilized eggs. Generally only 100 to 200 juvenile seahorses are actually produced per pregnancy (Lally and Hough, 1999).
Breeding interval: Breeding may occur every 20 to 28 days.
Breeding season: Breeding occurs year round.
Range number of offspring: 1405 (high) .
Average number of offspring: 20-1000.
Range gestation period: 20 to 28 days.
Range time to independence: 20 to 28 days.
Average age at sexual or reproductive maturity (female): 14 weeks.
Average age at sexual or reproductive maturity (male): 14 weeks.
Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); oviparous
Like other seahorses, H. kuda has an unusual mode of reproduction where the female provides the eggs but the male carries and cares for the embryos in its brooding pouch ("Project Seahorse, 2003). While the male carries its brood for 20 to 28 days, the developing larvae are constantly nourshied with a placental-like fluid that is secreted within its pouch. This fluid removes waste products and supplies the fertilized eggs with oxygen and nutrients. As the pregnancy proceeds, the placental fluid gradually changes its chemical content and becomes more similar to the surrounding seawater. This fluid change minimizes the shock newborns experience when they hatch and are released into an environment with higher salt content. These newly released juveniles are fully independent and do not require any parental care once they leave the brooding pouch.
Parental Investment: pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Male, Protecting: Male)
Hippocampus kuda is a species of seahorse, also known as the common seahorse, estuary seahorse, yellow seahorse or spotted seahorse. The common name sea pony has been used for populations formerly treated as the separate species Hippocampus fuscus, now a synonym of H. kuda.
The yellow seahorse is a small fish that can reach a length of 17–30 cm. The body is quite large, elongated, and has no spines, all bumps are rounded. The head is relatively large compared to the body. The snout is short and thick. The coronet is small and rises towards the rear, it can also sometimes have more or less long filaments. Some adults have a black line running through the dorsal fin in the direction of its width. The body coloration is often dark with a grainy texture but can also be yellow, cream, or reddish blotches and numerous small dark spots.
The seahorse possesses a tail that is used as a bending and grasping appendage. The seahorse is able to bend its tail ventrally due to its possession of body plates. The hypoxia muscle is responsible for bending the seahorse's tail. The plates send forces to the hypoxia muscles to ensure bending of the tail. These functions of the musculoskeletal system allow us to understand the anatomy of seahorses in further depth.
Hippocampus kuda inhabits waters from the Persian Gulf to Southeast Asia, Australia, Japan, and several Pacific islands including Hawaii, and is also found the eastern coast of Africa from Tanzania to South Africa, including the Indo-Pacific region ranging from the northwest Indian Ocean to the central areas of the Pacific Ocean. The majority of H. kuda populates the Chinese coast down to Australia.
H. kuda inhabit estuaries, lagoons, harbors, littoral zones, and coastal seagrass beds, where they are found in shallow waters of up to fifty-five meters in depth. Their habitat regions can include (but are not limited to) tropical, saltwater, or marine regions.
The mating system of H. kuda is completely monogamous. The species engages in a unique courtship ritual before engaging in mating. The male will change its color patterns and dance around the female and while producing a clicking with the coronet. Eventually, the tails of the male and female intertwine and the female will place her eggs into the male's ventral brood pouch via an ovipositor. There may be up to one-thousand eggs in a singular pouch, where the developmental process can last from twenty to twenty-eight days. Birth, however, depends largely on the monsoon patterns, lunar cycles, and water temperature. Males typically go into labor during a full moon, and after birth, the baby seahorses average a length of seven millimeters.
H. kuda are omnivores, feeding on minuscule living prey, such as larval fishes and zooplankton, via suction feeding. They are not strong swimmers. Predators of H. kuda include crabs, rays, tuna, and sea turtles, as well as humans.
H. kuda are extremely valuable to the traditional Chinese medicine trade. H. kuda has been said to regulate nervous, reproductive, endocrine, and immune systems. 25 million seahorses are used every year for medicinal purposes. The largest known exporters of H. kuda are Vietnam, India, the Philippines, and Thailand.
H. kuda is a popular species among aquarium keepers. Common seahorses have very small mouths, eating only small animals like brine shrimp and even newborn guppies. Seahorses need to eat approximately 4–5 times daily. Many aquarists who have kept H. kuda cultivate their own brine shrimp and rotifers. Daphnia is eaten when other foods are unavailable.[3]
Seahorses spend most of their time anchoring to coral reefs and branches with their tails because they are poor swimmers. They therefore need similar anchor points in the aquarium. Seahorses like a quiet tank, without large, belligerent fish, and a slow-moving current. Aquarists have found them to be generally accepting of tankmates like Synchiropus splendidus and other bottom-dwelling fishes.[3]
Common seahorses generally do best at a temperature of 72–77 °F (22–25 °C), optimally 73–75 °F (23–24 °C). They do not tolerate even spikes above 80 °F (27 °C) well.[4] Their optimal pH range is around 8.1–8.4.[5] The common seahorse can tolerate a range of salinity from 18 parts per thousand (ppt) to 36 ppt but salinity below about 25ppt should be promptly corrected. About 32 ppt is ideal.[6]
The species is still commonly encountered (especially in Indonesia and New Guinea) but is currently classified as vulnerable by the IUCN, as populations face some threat from bycatch in the shrimp trawl fishery, targeted catch for the aquarium and traditional medicine trade, and habitat destruction, coupled with low fecundity due to the involved method of parental brood care. Internationally, it is also listed in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which means that it is not necessarily threatened with extinction, but its trade must still be controlled in order to avoid utilization incompatible with their survival. Populations of H. kuda have declined by 30% in the last few decades due to pollution, habitat destruction, and illegal trading in Chinese medicine.
Hippocampus kuda is a species of seahorse, also known as the common seahorse, estuary seahorse, yellow seahorse or spotted seahorse. The common name sea pony has been used for populations formerly treated as the separate species Hippocampus fuscus, now a synonym of H. kuda.
