FusedJaw: Seahorses, Pipefish & Seadragons

Reprinted  from the 2005 Syngnathid Husbandry Manual with permission.

Seadragons in captivity.

Species Description

The Leafy seadragon, Phycodurus eques, the most ornate member of the family Syngnathidae, has long been known to aquarists as one of the most beautiful and unique of all the fishes. Found only in Southern and Western Australian waters, the Leafy seadragon is a master of camouflage. Named for the dragons of Chinese myth, this relative of the pipefishes and seahorses is named for the leaf-like appendages that adorn its body.

Natural Habitat

Inhabiting the rocky coastal areas, at depths of 20-25 meters, the seadragons can be found drifting between the blades of kelp or clumps of Sargassum, to which they bear a striking resemblance. Leafy seadragons and their close relatives the Weedy seadragon, Phyllopteryx taeniolatus, can be located near piers and jetties sheltered by the seaweeds that grow on them, and at deeper depths with rocky structures and sandy patches. They are often found with seagrasses known as sea nymph Amphibolus antarctica, and brown algaes and kelps such as Ecklonia radiata, Macrocystis angustifolia, Cystophora moniliformis, Cystophora subfarcinata, and Cystophora retorta. They can also be found in clumps of Sargassum sp. (Quong 2002)

A field study describing the patterns of movements and habitat use by Leafy seadragons was conducted by Connolly et al near Wright Island in South Australia and found that during their study period ultrasonically tagged Leafy seadragons spent more time over Posidonia seagrass and less time over other sea grasses or kelps. The authors state that these findings might result directly from habitat selection by seadragons, or indirectly from seadragons positioning themselves in response to other factors such as water movement or prey abundance. (Connolly et al 2002)

Leafy seadragons are found in a temperate climate where the water temperature remains very cool for most of the year. According to information available from the National Tidal Facility (NTF) which runs an Australian Baseline Sea Level Monitoring Project, the temperatures in the coastal areas where seadragons are commonly found ranges from approximately 11 degrees C in the coldest months of June through September, to as high as 23 degrees in the warmer months of December through March. (Moore 1999)

Temperatures recorded from sites frequently visited by collector Pang Quong when observing seadragons in the wild, range from a low of 9 degrees C to 21 degrees C. His observations are similar to those recorded by the NTF (Quong 1999). Photoperiods in the areas where dragons are most commonly found are based upon the total time between sunrise and sunset. The photoperiods coincide with the water temperature with the shortest days occurring in June (~ 10 hours) and the longest in December (~ 14.5 hours) (Galbraith 2005).

Selection and Suitability

Leafy seadragons can be an expensive and difficult species to display and maintain. To date, the Leafy seadragon has not successfully reproduced in captivity. At the present time, availability of Leafy seadragons is limited to exchange between zoological institutions, or purchase from Pang Quong or an aquarium wholesale facility to which he sells captive raised leafy seadragons. Collection of Leafy seadragons from the wild has been limited to only a few individuals over the past decade. The Leafy seadragon is South Australia’s state marine emblem and is considered a fully protected species. (PIRA 2005). The young seadragons available from Pang are very small and have been raised from the eggs pregnant males he is permitted by the South Australia Government to collect from the wild each year. These animals are generally only available in the first few months of the year, and the number of animals available varies from year to year. Freight and import charges can be expensive.

Leafy seadragons have a very selective diet, requiring live or frozen mysid shrimp, or small, cultured or wild caught Penaeid shrimp. Acquiring the live wild caught mysid shrimp can be expensive, and culturing live mysid shrimp can be time consuming. Should the Leafy seadragon reproduce successfully, the young animals will require live foods until they can be weaned, which can increase the expense in maintaining a collection (Forsgren 2001).

In addition to their limited availability and expense involved in acquiring them, Leafy seadragons have limited compatibility with other fish and invertebrate species. Several zoological institutions have displayed Leafy seadragons with Weedy seadragons, Phyllopteryx taeniolatus, and with Pot bellied seahorses, Hippocampus abdominalis . A number of invertebrates can be kept safely with seadragons, although problems have been reported with crabs that accidentally grow up from the mysid shrimp shipments.

Age, Growth and Reproduction

Juvenile Leafy SeaDragon. Photo courtesy of Stacina.

Little is known about the life history of the Leafy seadragon. It has only been since the late 1990s that there has been any success in maintaining this species long-term in an aquarium environment (Powell 1997). Scientific literature pertaining to the life history of seadragons is quite limited. In December 1985, Rudy Kuiter conducted a study on the growth rates of newly hatched Leafy seadragons for Australia’s national television station. In that study, the newly hatched dragons measured 35 mm in length. After 21 days in temperatures ranging from 17 degrees C to 21 degrees C, the juveniles attained a length of 85 mm (Kuiter 1988). A similar study was conducted by the staff at Underwater World Perth in late 1992, and early 1993. The growth rates were observed in a number of newly hatched juvenile Leafy seadragons for a period of ten weeks. During that study period the specimens in one of the rearing tanks was found to have a growth rate of approximately 9 mm per week at 18 degrees C (Mackay 1996). Pang Quong of PQ Aquatics reports that typically in the first 10-12 weeks the juvenile Leafy seadragons at his facility grow at a rate of approximately 10 mm per week (Quong 2005). Leafy seadragons mature at length greater than 20 cm usually around two years of age (Kuiter 1988).

An informal survey conducted by Charles Delbeek of the Waikiki Aquarium, Hawaii in 2004, polled members of the Aquatic info and Syngnathidae list serve groups as to the longevity of the Leafy seadragons in their collections. He recorded the results in a table and the incomplete results are listed below. From this anecdotal evidence, and the fact that facilities are, just within the past decade, able to keep Leafy seadragons long-term, the estimated life span of a Leafy seadragon is believed to be approximately ten years (Delbeek 2004). (See Table 1 below)

Table 1

Institution Years in Captivity Source Year Hatched

• Long Beach - 8 Years in Captivity - PQ
• Shedd Aquarium - 8 Years in Captivity -   DWA/PQ -  1998
• Omaha Henry Doorly Zoo  - 6 Years in Captivity -  DWA/PQ -  Dec. 1998
• Toba Aquarium, Japan - 9 Years in Captivity - Wild - ?
• Dallas World Aquarium  - 8 Years in Captivity -  Wild  - Collected as adult 1996
• Waikiki Aquarium  - 3  Years in Captivity - PQ - Jan. 2000
• Ripley’s Aquarium of the Smokies –   3 Years in Captivity -   ?
• New England Aquarium  - 5+ Years in Captivity - DWA/PQ -  1997
• Seattle Aquarium –  4+ DWA/PQ  - 1999

PQ = Pang Quong, PQ Aquatics DWA = Dallas World Aquarium DWA/PQ= Loan from DWA, originally raised by Pang Quong

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