JMBA

GLOBALmarine environment SUMMER 2005 Issue 2 GLOBAL NEWS The complex world Tsunami and Needlefish

of siphonophores Also in this issue: DECLINE OF A DOVER STRAIT HARBOUR SEAL TEMPERATURE EFFECTS ON MOON ICONOGRAPHY AND JELLYFISH EVOLUTION ANGLERFISH FEEDING IN THE SHETLANDS JELLYFISH INVADE POWER STATIONS CTENOPHORES IN THE BLACK SEA HUMAN JELLYFISH INTERACTIONS UNIQUE SCALLOP GARDEN CLIMATE CHANGE & FISH how many LIFE ON LIVING ISLANDS LITTLE WHITE OCTOPUS dolphins are left? FISH LICE ON COD THE PURPLE CLAM

JELLYFISH MAY Reproduction in BENEFIT FROM sharks and rays GLOBAL CHANGES richardi

S teven H.D. Haddock and C asey W. Dunn Bluewater SCU BA diving to collect siphonophores Email: [email protected] IF S IPHONOPHOR ES AR E S O S PEC IAL, WHY HAVE MANY PEOPLE NEVER HEAR D OF THEM? UNLIKE THE PORTUGUES E MAN O’ WAR — A NON-R EPR ES ENTATIVE S PEC IES WHIC H HAS C OME TO R EPR ES ENT THE GR OUP IN MOS T TEXTB OOKS — MOS T TYPES AR E FOUND B ELOW THE S UR FAC E, AND AWAY FROM THE C OAS T. THEY AR E EXTR EMELY FR ANGIB LE, B R EAKING APART IN NETS OR WHEN MER ELY ILLUMINATED, AND THEY R EQUIR E S PEC IAL MEANS OF C OLLEC TION, S UC H AS B LUE-WATER S C UB A DIVING OR S UB MER S IB LES .

f you think of a dominant predator in the sea, you the length of the train and distributed to the rest of probably imagine a shark, killer whale, or perhaps a . Most species grow by adding ‘cars’ just I giant squid. Unless you are a marine biologist (or a behind the train engine (nectophores). This allows species of ), you probably would not them to reach great lengths: they range in scale from think of – or perhaps even know of – the about a centimetre to more than 10 metres. In fact, siphonophores. These planktonic cnidarians, the species dubia may be the longest however, have a much greater ecological effect than on earth. their better-known counterparts. There may be no S iphonophores are unique in many ways. Typically, movies featuring siphonophores, but they are among each gastrozooid has its own and can catch the most abundant and effective carnivores in the and process prey independently. Therefore as the sea. length and number of increase, the S iphonophores are hydrozoans, related to jellyfish predatory impact of an individual is multiplied by the and corals, but they aren’t radially symmetric as you area of this long curtain of continuously fishing might expect a cnidarian to be. They are elongate tentacles. S ome species even use a variety of tricks and in many ways bilaterally symmetrical, taking on to lure prey directly to their stinging cells. Even complex forms that look strange even among other humans would do well to avoid the species with marine invertebrates. The most similar might black, purple, or green colouration — these are be a hydroid, growing along a rock and sprouting usually fish-eaters, and while they won’t kill you, their polyps, but which suddenly takes to the water sting is powerful enough to penetrate through latex column. Each siphonophore is a consisting of gloves. On the other hand, you would be lucky to see a few basic types of zooids attached in many one because these are typically found deeper than repeating series along a central stem. Zooids have 500 metres. Most siphonophores are bioluminescent, specialized functions and are arranged like a and they can produce dramatic light shows when locomotive, usually with propulsion at one end, and disturbed. S ome, including many newly discovered feeding, protective, and reproductive units trailing deep-sea species, are fluorescent, iridescent, or behind. Through the central stem, food can be capable of blanching to a milky white (or all of the conveyed from the ‘feeding cars’ (gastrozooids) along above!). 24 JMBA G lobal Marine Environment S iphonophores have not always been so esoteric: the most famous biologists of the 19th century pondered and debated their structures and origins. Later marine biologists directed their efforts toward large-scale and rapid trawling, methods which are poorly suited to returning intact specimens of gelatinous taxa. Our knowledge of siphonophore would have stagnated during the last 70 years if not for the work of two B ritish scientists. A.K. Totton described numerous species during the 1940s and 1950s, but even more importantly, he synthesized, summarized, and organized what was known about the group in his monograph of 1965. S ince the 1980s, Phil Pugh has incorporated his numerous species descriptions into influential papers which examine and clarify entire siphonophore families. This month, with Pugh’s involvement in his 25th and 26th species descriptions, he becomes the most prolific siphonophore taxonomist ever. With the application of molecular genetics and greater access to the , we head to a future filled with insight into the evolution, relationships, and development of these unique superorganisms.

The Chronology of Siphonophore Taxonomy 16 AUTHOR: Various Totton Pugh Total: 162 14 Haeckel, Chun Carré, Stepanjants, Margulis Quoy & Gaimard 12 Bigelow 10 8

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0 1 7 5 0 - 1 8 0 1 8 3 0 1 8 5 0 1 8 7 0 1 8 9 0 1 9 0 1 9 3 0 1 9 5 0 1 9 7 0 1 9 0 Decade beginning

Further reading: Totton, A.K., 1965. A S ynopsis of the S iphonophora. B ritish Museum of Natural History, London. Lilyopsis fluoracantha Kirkpatrick, P.A. & Pugh, P.R ., 1984. S iphonophores and velellids: keys and notes for the identification of the species. Linnean Society of London, London. Mackie, G.O., Pugh, P.R . & Purcell, J .E., 1987. S iphonophore biology. Advances in Marine Biology, 24, 97-261. Haddock, S .H.D., 2004. A golden age of gelata: past and future research on planktonic ctenophores and cnidarians. Hydrobiologia, 530/531, 549-566. Haddock, S .H.D., C .W. Dunn, P.R . Pugh. and C .E. S chnitzler., 2005. B ioluminescent and red-fluorescent lures in a deep-sea siphonophore. Science. 309:263

Published in JMBA Pugh, P.R . 1992. The status of the genus Prayoides (S iphonophora: ). J MB A 72, 895-909. Pugh, P.R . & Pagès, F. 1993. A new species of Clausophyes (S iphonophorae, C lausophyidae), with a redescription of C . galeata and C . moserae. J MB A 73, 595-608. Pugh, P.R . & Harbison, G.R . 1986. New observations on a rare physonect siphonophore, Lychnagalma utricularia (C laus, 1879). J MB A 66, 695-710. Pugh, P.R . & Youngbluth, M.J . 1988. A new species of (S iphonophora, , Agalmidae) collected by submersible. J MB A 68, 1-14 Haddock, S .H.D., Dunn, C .W. & Pugh, P.R ., 2005. A reexamination of siphonophore terminology and morphology, applied to the description of two new prayine species with remarkable bio-optical properties. J MB A 85(3), 695–707 Physalia physalis