The weedy seadragon Phyllopteryx taeniolatus

VIDEOS

2010-02-25T15:31:00.023+01:00

You can see some of our video footages in ABC program Catalyst

More video footages:

Leafy seadragons, Rapid Bay, SA

Weedy seadragons, Kurnell

Weedy seadragons, Kurnell

Weedy seadragons, North Bondi

Weedy seadragons, Kurnell

Weedy seadragons, Kurnell

We will be slowly uploading more videos, editing is a very hard task...

PUBLICATIONS

2010-02-25T15:27:00.010+01:00

Sanchez-Camara J, Martin-Smith M, Booth DJ, Fritschi J, Turon X (2011). Demographics and vulnerability of a unique Australian fish, the weedy seadragon Phyllopteryx taeniolatus. Marine Ecology Progress Series 422: 253-264.

Sanchez-Camara J (2010) Biology and Ecology of the weedy seadragon Phyllopteryx taeniolatus (Pisces: Syngnathidae) and their implications for the species' conservation. PhD Thesis. University of Barcelona, Spain. Ask for PDF

Sanchez-Camara J, Fritschi J (2008) Ecología del dragón de mar común Phyllopteryx taeniolatus. Acuario Práctico 762, 48-56.

Sanchez-Camara J, Booth DJ (2007) Weedy seadragon Phyllopteryx taeniolatus: review of ecology and management. Report for Sydney Water Corporation.

Sanchez-Camara J, Booth DJ, Murdoch J, Watts D, Turon X (2006) Density, habitat use and behavior of the weedy seadragon Phyllopteryx taeniolatus (Teleostei: Syngnathidae) around Sydney, New South Wales, Australia. Marine and Freshwater Research 57, 737-745.

Sanchez-Camara J, Booth DJ, Turon X (2005) Reproductive cycle and growth of Phyllopteryx taeniolatus. Journal of Fish Biology 67, 133-148.

Sanchez-Camara J, Booth DJ (2004) Movement, home range and site fidelity of the weedy seadragon Phyllopteryx taeniolatus (Teleostei: Syngnathidae). Environmental Biology of Fishes 70, 31-41.

SEAHORSES AT CHOWDER BAY, SYDNEY HARBOUR

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Photos of a single dive conducted in December 2004 to admire the seahorses of Sydney Harbour

A TRIP TO TWO FOLD BAY

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During December 2007 we conducted a trip of several days to Two Fold Bay (37 S) to study the seadragon populations there. In particular we wanted to corroborate the latitudinal differences observed between the studied NSW (34 S) and Tasmanian populations (43 S).

POTENTIAL THREATS TO POPULATIONS

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Patterns shared among Northern and Southern seadragon populations that make them vulnerable are: low density, extremely low fecundity, life-time restricted home ranges in a threatened habitat, lack of a dispersive egg phase, limited dispersal of the young and low emigration and relocation rates. This is compensated by fast growth and high survival rates and a greater life span compared to most syngnathids.
From 2001 to 2009, we found evidence of population declines in NSW and TAS populations. The main concern is whether these were temporary declines produced by natural causes, such as interannual fluctuations in recruitment, or were due to anthropogenic disturbances. Habitat loss is, after exploitation, the main cause of extinction in marine populations, but invasive species, climate change, pollution and disease, all account in the list of potential threats. During our study, a non-identified disease was observed in the skin of some seadragons. Another impact that poorer water quality and degradation of the habitat can have is a reduction in the mysid populations which represents 80 % of the diet of P. taeniolatus.

BIODIVERSITY

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Incredible variety of fishes and invertebrates at the study sites in NSW. Great variety of sponges and starfish, Port Jackson sharks, blind sharks, wobbegongs, leatherjackets, bluedevils, seahorses, giant cuttlefish, stingrays.....

see full gallery biodiversity NSW sites

And awesome also in Tasmania...

see full gallery biodiversity TAS sites

ABUNDANCE, HABITAT, BEHAVIOUR

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Distribution, abundance and sex ratios of seadragons were temporally stable, suggesting no large-scale seasonal migrations. Sex ratios were close to 1:1. Individuals were concentrated near the border of the kelp and the sand except when exhibiting hiding behaviour, when they were more often found in the kelp beds. The same kelp beds were the least used habitat when feeding . Pregnant males tended to hide more often than other seadragons and therefore were more frequent in kelp and kelp patches. Seadragons tended to be solitary although pairing and grouping behaviour was also observed. Pairings between male-female were more common than pairings of the same sex.

Feeding on mysids

Paring and grouping was common...

Amazing camouflage behaviour. Observed only once!

Hidden in the kelp bed was more common

See full gallery abundance, habitat and behaviour in NSW
See full gallery abundance, habitat and behaviour in TAS

RECRUITMENT AND GROWTH

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Seadragons exhibit slower growth in Tasmania (43 S) compared to New South Wales (34 S); the estimate of the growth parameter k of the von Bertalanffy growth equation was 1.57 yr^-1 (r² of the regression= 0.990) for NSW seadragons and 0.91 yr^-1 (r² of the regression= 0.915) for TAS seadragons

See full gallery recruitment and growth

REPRODUCTIVE CYCLE

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In NSW, brooding males were present for a period of more than 6 months, from June-July to early-January. The percentage of males that were pregnant in the studied areas peaked in November-December, near the end of the breeding season. Two pregnancies were reported for some males. The gestation periods observed were of 30 to 38 days.

Birth and recruitment occurs 3 months later in Tasmania (43º S, near Hobart) compared to NSW (34 ºS, near Sydney). In TAS, breeding seasons are shorter but gestation periods are longer. In shallow waters of NSW and TAS, the eggs are frequently covered with algae.

See full gallery reproduction in NSW
See full gallery reproduction in TAS

MATERIAL AND METHODS

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Study sites

Most of this study was carried out during 2001, 2002, 2004 and 2007 at three sites around Sydney, New South Wales (NSW), Australia. The 3 sites of study were rocky reef formations parallel to shore with presence of kelp Ecklonia radiata. Sites 1 and 2 were at Kurnell, Botany Bay. Site 3 was at North Bondi. Aditional occasional surveys were conducted at other sites around Sydney. In order to compare seadragon populations from different areas , fieldwork was also conducted in collaboration with Project Seahorse in 2003, 2004 and 2009 at Kingston Beach and Blackman's Bay, Tasmania (TAS).

Sampling and tagging protocol

All tagging and observations were conducted using SCUBA. Waterproof data sheets with a standardised seadragon outline were taken underwater. Seadragons were tagged with VIFE injectors (Visual Implant Fluorescent Elastomer). The tagging was done in situ by gently restraining the animal with one hand and injecting the the tagging material with the other. No signs of adverse reaction to the tagging were observed with some fishes showing feeding behaviour immediately after tagging.

See full gallery Material and Methods NSW

See full gallery Material and Methods TAS

INTRODUCTION

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Phyllopteryx taeniolatus Lacépède is the only member of the genus Phyllopteryx (Family Syngnathidae) and, along with the leafy seadragon Phycodurus eques Günther, are the only representatives of what are commonly known as seadragons. The family Syngnathidae, which also includes seahorses, pipefishes and pipehorses, is unique among fishes with males incubating the eggs deposited by the female in a specialised incubation area or brood pouch on either the tail or the trunk of the male (Herald, 1959). The weedy seadragon is distributed from Port Stephens, New South Wales, on Australia’s eastern coast to Geraldton, Western Australia, on Australia’s western coast, including the waters around Tasmania (Hutchins & Swainston, 1986). They live among the larger algae on exposed reefs and feed mainly on mysid crustaceans (Edgar 2000).

Phyllopteryx taeniolatus is listed as Lower Risk (conservation dependent) by the Department of Environment and Water Resources of Australia (Pogonoski et al., 2002) and as Near Threatened by the IUCN Red List of Threatened species (Connolly, 2006) . Weedy seadragons are protected under the Commonwealth's Environmental Protection and Biodiversity Conservation (EPBC) Act (1999). Additionally, particular protection laws have been deployed in the different Australian states where seadragons are present (Connolly 2006). For instance, the weedy seadragon is fully protected in New South Wales, Australia, under the Fisheries Management Act 1994, considered Protected Aquatic Biota in Victoria and The Tasmanian Living Marine Resources Management Act 1995 prohibits the capture of all syngnathids in Tasmania. However, protection came before knowledge; at the beginning of this Thesis, in 2001, P. taeniolatus was listed by The World Conservation Union (IUCN) as “Data Deficient" meaning that insufficient information was available to make an assessment of the species’ risk of extinction.

The lack of scientific studies on this species is surprising if we consider that P. taeniolatus is a vulnerable, endemic and charismatic fish. For instance, in the state of Victoria, P. taeniolatus is the official marine state emblem, selected by public nomination. This particular nature, added to its extraordinary beauty make P. taeniolatus an iconic and an extraordinary flagship species in marine conservation.

The two main reasons why we started this project in 2001 were; (1) add knowledge to a poorly-known emblematic, vulnerable and endemic fish species, (2) the firm conviction that a better knowledge of P. taeniolatus was necessary for proper management of this flagship fish. Our first aim was to determine, using a non-destructive method of in situ monitoring, the movement patterns and home ranges of weedy seadragons and to record evidence of their site fidelity. A second aim of this study was to provide specific information on the reproductive cycle and growth of the weedy seadragon in their natural environment. We were interested in determining the duration of the breeding and the recruitment period, the number of pregnancies per season, the duration of pregnancies and intervals and the size and age of first maturity. We wanted to determine growth and average and maximum sizes.A third goal was to measure abundance, sex ratios and distribution of weedy seadragons at different locations. We also aimed to determine the habitat and behaviour of weedy seadragons. Our last aim was to provide population dynamics parameters and to determine latitudinal and temporal trends of this protected and potentially threatened fish.

See full gallery NSW pics

See full gallery TAS pics