Diagnosis of Leptolida
Leptolida are Hydrozoa that have a life cycle fundamentally alternating between two stages. A planktonic, sexual medusoid stage (the meduse or medusa) gives rise to a short-lived planula larva that metamorphoses into a sessile vegetative (non-sexual) polypoid stage (the hydroid). The Class Leptolida and Class Siphonophora together form the cnidarian Superclass Hydrozoa (or Subphylum Hydrozoa, see Cornelius, 1995a). The anatomy of a typical leptomedusa is depicted in Leptolid. The topology of the radii is presented in Radii-diagram.
Note that the medusae of the following species occurring as polyp in the North Sea, are unknown (all Family Tubulariidae, Subclass Leptothecatae): Ectopleura larynx Ellis and Solander, 1786 (syn. Tubularia larynx), Tubularia bellis Allman, 1863, Tubularia indivisa Linnaeus, 1758, and Tubularia regalis Boeck, 1860. Furthermore, the meduse of Sarsia lovenii (M. Sars, 1846) [Family Corinidae, Subclass Anthoathecatae] is not liberated from the polyp colony, and therefore absent from the plankton. The above five species have been omitted from the list of plankton species.
Identification of Leptolida
In (sub) recent literature no effort was, or could be made to construct a key for the medusoid stages of the NE Atlantic species of Leptolida (see, for instance, Russell, 1953a, Cornelius, 1995a and Cornelius, 1995b). However, this CD-ROM offers three ways to identify North Sea leptolid medusae to species: a di-/trichotomous text key, a multiple-entry key and quick reference charts, respectively.
1) The text key was composed with the use of the key to genera by Bouillon and Boero, 2000 and the (lower) keys to species, where available, in Russell, 1953a. For Sarsia no keys appeared to exist and for the five North Sea species belonging to this genus, a key was constructed based on Edwards, 1978 and Schuchert, 2001. The text key starts at Page 60: Leptolida text key.
2) The multiple-entry key uses an object-character state matrix composed with species descriptions in Russell, 1953a, Cornelius, 1995a and Cornelius, 1995b. This matrix file is called "Leptolida", that is located in the Identify files folder, and has to be used with the IdentifyIt⢠module, to be found in the Navigator or in the windows menu. To read more about this key and how to apply it for identification, we refer here to page The Leptolida multi-entry key.
3) Quick reference charts with the pictorial outlines of the medusae is presented in the eight figures below.
Medusae-pictorial1
Medusae-pictorial2
Medusae-pictorial3
Medusae-pictorial4
Medusae-pictorial5
Medusae-pictorial6
Medusae-pictorial7
Medusae-pictorial8
The following species of Leptolida are included in the present volume:
Subclass Anthoathecatae
Order Capitata
Family Corymorphidae
Corymorpha nutans
Eucodonium brownei
Family Corynidae
Cladonema radiatum
Coryne eximia
Coryne producta
Coryne prolifera
Dipurena halterata
Dipurena ophiogaster
Dipurena gemmifera
Sarsia lovenii
Sarsia occulta
Sarsia piriforma
Sarsia striata
Sarsia tubulosa
Family Euphysidae
Euphysa aurata
Euphysa tentaculata
Family Margelopsidae
Margelopsis haeckeli
Margelopsis hartlaubi
Family Porpitidae
Velella velella
Family Tubulariidae
Ectopleura dumortieri
Hybocodon prolifer
Tubularia larynx
Tubularia bellis
Tubularia indivisa
Tubularia regalis
Family Zancleidae
Zanclea costata
Order Filifera
Family Bougainvillidae
Bougainvillia britannica
Bougainvillia macloviana
Bougainvillia muscoides
Bougainvillia muscus
Bougainvillia principis
Bougainvillia pyramidata
Bougainvillia superciliaris
Lizzia blondina
Nemopsis bachei
Family Calycopsidae
Bythotiara murrayi
Family Clavidae
Turritopsis nutricula
Family Hydractiniidae
Podocoryne areolata
Podocoryne borealis
Podocoryne carnea
Family Pandeiidae
Amphinema dinema
Amphinema rugosum
Catablema vesicarium
Halitholus yoldiaarcticae
Leuckartiara breviconis
Leuckartiara nobilis
Leuckartiara octona
Neoturris pileata
Family Rathkeidae
Rathkea octopunctata
Family Trichydridae
Trichydra pudica
Subclass Leptothecatae
Order Conica
Family Aequoreidae
Aequorea forskalea
Aequorea macrodactyla
Aequorea vitrina
Family Dipleurosomatidae
Dipleurosoma typicum
Family Eirenidae
Eirene viridula
Eutima gegenbauri
Eutima gracilis
Eutonina indicans
Helgicirrha schulzei
Phialopsis diegensis
Tima bairdi
Family Eucheilotidae
Eucheilota flevensis
Eucheilota maculata
Family Laodiceidae
Laodicea undulata
Ptychogena crocea
Staurophora mertensii
Family Lovenellidae
Lovenella clausa
Family Malagazziidae
Octocanna funeraria
Family Melicertidae
Melicertum octocostatum
Family Mitrocomidae
Halopsis ocellata
Cosmetira pilosella
Cyclocanna welshi
Mitrocomella brownei
Mitrocomella polydiademata
Family Phialellidae
Phialella quadrata
Family Tiarannidae
Modeeria rotunda
Family Tiaropsidae
Tiaropsis multicirrata
Order Proboscoida
Family Campanulariidae
Clytia hemisphaerica
Clytia islandica
Obelia spp
Orthopyxis integra
Subclass Limnomedusae
Family Olindiasidae
Gonionemus vertens
Gossea corynetes
Family Proboscidactylidae
Proboscidactyla stellata
Subclass Narcomedusae
Family Solmaridae
Solmaris corona
Subclass Trachymedusae
Family Geryonidae
Liriope tetraphylla
Family Ptychogastriidae
Ptychogastria polaris
Tesserogastria musculosa
Family Rhopalonematidae
Aglantha digitale
Homoeonema platygonon