Stauridiosarsia producta (Wright, 1858)

Gravili, Cinzia, Vito, Doris De, Camillo, Cristina Gioia Di, Martell, Luis, Piraino, Stefano & Boero, Ferdinando, 2015, The non-Siphonophoran Hydrozoa (Cnidaria) of Salento, Italy with notes on their life-cycles: an illustrated guide, Zootaxa 3908 (1), pp. 1-187 : 57-59

Stauridiosarsia producta (Wright, 1858)

Fig. 39 A, B

See Nawrocki et al. (2010) and Schuchert (2010) for a complete synonymy.

Material examined. HCUS-S 0 44 (Hydrozoa Collection, University of Salento—fauna of the Salento Peninsula)—polyp stage.

Description (based on our own observations; Brinckmann-Voss 1970; Schuchert 2001b; Schuchert 2010):

Hydroid. Hydrorhiza formed by a network of creeping ramified stolons; colonies stolonal; hydrocaulus short, unbranched or rarely slightly and irregularly branched, covered by smooth perisarc; hydranth clavate, larger distally, up to 1.5 mm high; hypostome short, dome-shaped; with 4–6 oral tentacles in one whorl and 1–4 alternating additional whorls of capitate tentacles, each with 3–6 tentacles, the uppermost one larger than the rest; with one whorl of 3–6 aboral filiform tentacles; medusa buds borne among or below the lowest whorl of capitate tentacles, 1–5 buds per hydranth. Colour: hydranth with reddish gastrodermis.

Habitat type. Rocky cliffs (depth range: 0–35 m) ( Brinckmann-Voss 1970; Schuchert 2001b).

Substrate. Several organisms such as the hydroid Tubularia indivisa , crab Maja squinado , Cardium (Mollusca) , Spartina spp. (Plantae), shells, Cystoseira (alga), Sabella tube (Annelida), barnacles, and on many other solid objects.

Seasonality. In the Ligurian Sea from February to November (Puce et al. 2009); February, June, July, September (this study).

Reproductive period. In the Ligurian Sea in February (Puce et al. 2009).

Medusa. Adult. Umbrella bell-shaped, up to 7 mm wide and 10 mm high, with thick walls, apical canal; manubrium cylindrical and with a distinct conical apical chamber, almost as long as subumbrellar cavity; mouth simple, tubular; radial canals entering endodermal chamber of bulbs in middle; gonads completely surrounding manubrium; four large marginal bulbs, perradial; each marginal bulb with one long marginal tentacle with many crescent-shaped cnidocyst clusters and a small cylindrical terminal cnidocyst knob; with a ocellus on each marginal bulb. Colours: apical canal and bulbs reddish or brown, ocelli black or dark brown.

Developmental stages. Newly released medusa 0.8–1.1 mm high, slightly less in diameter, with apical canal and scattered nematocysts on exumbrella.

Cnidome. Stenoteles (polyp); stenoteles and desmonemes (medusa).

Distribution. Atlantic, Mediterranean ( Kramp 1959, 1961; Altuna 1994; Benović & Lučić 1996; Medel & López-González 1996; Schuchert 2001b; Bouillon et al. 2004; Gravili et al. 2008a; Puce et al. 2009).

Records in Salento. Rare at: La Strea, Porto Cesareo ( Faucci & Boero 2000); Otranto ( Miglietta et al. 2000; Gravili 2006; Gravili et al. 2008a); Costa Merlata ( Andreano 2007). Other Apulian records: Gargano ( Fraschetti et al. 2002).

Remarks. The ultrastructure of receptors in the filiform tentacles was studied by Golz & Thurm (1994). Orlov (1996) investigated aspects of the ecology and feeding behaviour of this species. Based on molecular information, Nawrocki et al. (2010) found S. producta to be associated with several species previously placed in the genera Coryne and Slabberia (= Dipurena ), in a clade with no clear morphological apomorphies; the authors thus reintroduced the genus Stauridiosarsia for this clade, with Stauridiosarsia producta as type species (by monotypy). Only the hydroid stage and the new born medusa were seen in the present study.

References. Rees (1938) as Stauridium productum ; Kramp (1959, 1961), Riedl (1959) both as Stauridiosarsia producta ; Brinckmann-Voss (1970, 1989) as Coryne producta ; Benović (1973), West (1974) as Sarsia producta ; Benović et al. (1987) as Stauridiosarsia producta ; Altuna (1994) as Sarsia producta ; Benović & Lučić (1996) as Stauridiosarsia producta ; Medel & López-González (1996), Orlov (1996), Faucci & Boero (2000) all as Sarsia producta ; Miglietta et al. (2000) as Coryne producta ; Schuchert (2001b as C. producta, 2010 as Stauridiosarsia producta ); Fraschetti et al. (2002) as Sarsia producta ; Bouillon et al. (2004), Gravili (2006), Gravili et al. (2008a), Puce et al. (2009) all as Coryne producta ; Nawrocki et al. (2010) as Stauridiosarsia producta .

Figures

FIGURE 39. Stauridiosarsia producta: A, hydranth; B, mature medusa (redrawn and modified after Russell 1953 by C. G. Di Camillo). Scale bars: A, 0.5 mm; B, 1.0 mm.