Calyptospadix cerulea Clarke, 1882

Calder, Dale R., 2019, On a collection of hydroids (Cnidaria, Hydrozoa) from the southwest coast of Florida, USA, Zootaxa 4689 (1), pp. 1-141 : 22-23

Calyptospadix cerulea Clarke, 1882

Fig. 2e

Calyptospadix cerulea Clarke, 1882: 136 , pl. 7, figs. 1–9.

Bimeria franciscana Torrey, 1902: 28 , pl. 1, fig. 4.

not Bimeria franciscana .— Joyce, 1961: 36, pl. 5, figs 3, 4 [= Bimeria humilis Allman, 1877 ].

Garveia franciscana .— Garman et al. 2011: 71.

Type locality. USA: Virginia, Hampton Roads, Fort Wool ( Clarke, 1882: 136) .

Material examined. Caloosahatchee River at Fort Myers, 26°38.790’N, 81°52.354’W, on floating dock, less than 1 m, 18 July 2012, 7‰, one colony, 7.5 cm high, with a few developing female gonophores, coll. D. Calder, ROMIZ B4340.— Caloosahatchee River at Fort Myers, 26°38.790’N, 81°52.354’W, on floating dock, less than 1 m, 18 July 2012, 7‰, one colony, 2.5 cm high, without gonophores, coll. D. Calder, ROMIZ B4341 .— Fort Myers Beach , Salty Sam’s Marina, 26°27’21.7”N, 81°56’34.6”W, on floating dock on oyster shells, <0.1 m, 24° C, 22 February 2018, five colony fragments, up to 5 cm high, with male gonophores, coll. D. Calder, ROMIZ B4342 .— Fort Myers Beach , Salty Sam’s Marina, 26°27’21.7”N, 81°56’34.6”W, on floating dock, <0.1 m, 29° C, 27 August 2018, three colony fragments, up to 13 cm high, with female gonophores, coll. D. Calder, ROMIZ B4417 .

Remarks. Calyptospadix cerulea Clarke, 1882 was originally described from Hampton Roads, Virginia, at the mouth of the James River estuary. The species has been reported relatively few times under that name, mostly from areas of reduced salinity along the Atlantic coast of North America ( Fraser 1944). Much resembling it is the more widely reported Bimeria franciscana Torrey, 1902 , first discovered in the San Francisco Bay estuary on the Pacific coast of the United States. That hydroid is commonly believed to be an invasive estuarine endemic with a disjunct but widespread geographic distribution in temperate and tropical regions. The only apparent morphological difference between the two putative species is the supposed number of planulae generated per female sporosac, with several originally reported in C. cerulea and one in B. franciscana . On examining specimens of the common morphotype from Virginia during this study, some colonies had gonophores with a single egg cell, corresponding to B. franciscana , while others had several cells or possibly zygotes, corresponding to C. cerulea . The latter were interpreted as cell aggregations resulting from cleavage of the single egg. Hydroids of the two were otherwise indistinguishable. Meanwhile, specimens examined here from Fort Myers Beach (ROMIZ B4417) had, on the same colony, some female gonophores with a single egg and others containing a varying number of cells. The latter were again taken to have been the result of cell division. While gonosomes of the two supposed species may differ, the apparent difference is believed to simply reflect different stages of embryological development. Thus, C. cerulea and B. franciscana are treated here as conspecific. Molecular analyses of populations from the two type localities, and ones supposedly differing in their gonosomes, are nevertheless needed to better resolve the synonymy of the two. Of the two subjective synonyms, the junior name ( B. franciscana ) is the more familiar. However, nomenclatural stability is not greatly threatened by application of the Principle of Priority, and C. cerulea is adopted here as the name of the species.

A change in the binomen Bimeria franciscana is necessary in any case because the species has been assigned to the wrong genus. These hydroids have been referred in most recent works to Garveia Wright, 1859 , as G. franciscana or G. cerulea . However, specimens do not match the diagnosis of that genus, as outlined by Schuchert (2007). Instead, Calyptospadix Clarke, 1882 is recognized here as valid, referable to family Bougainvilliidae Lütken, 1850 , and the original binomen of the species ( Calyptospadix cerulea ) is restored. Meanwhile, Garveia was recently removed from Bougainvilliidae to Pandeidae Haeckel, 1879 in having vasiform hydranths surrounded by pseudohydrothecae, and notably robust hypostomes (see Calder 2017). Molecular data in Prudkovsky et al. (2016) provide additional support for assignment of Garveia to Pandeidae . As noted earlier, Bougainvilliidae as presently constituted is taken to be polyphyletic ( Mendoza-Becerril 2018a).

Hydroids identified here as C. cerulea were abundant on a floating dock at 26°38.790’N, 81°52.354’W in the Caloosahatchee River estuary at Fort Myers, Florida, during July 2012 (ROMIZ B4340, ROMIZ B4341). In the aftermath of Hurricane Irma passing through south Florida in September 2017, a massive discharge of fresh water passed through the estuary from Lake Okeechobee upstream. Colonies of C. cerulea disappeared at that location un- der salinities of less than 1‰ and were replaced by the more fresh-water tolerant Cordylophora caspia . Instead, hydroids of the species appeared down-estuary in Estero Bay on floating docks at Salty Sam’s Marina (26°27’21.7”N, 81°56’34.6”W), San Carlos Island, in winter 2018 (ROMIZ B4342). Colonies with abundant female gonophores were found at the same location in late summer 2018 ( ROMIZ B4418 ) .

Calyptospadix cerulea has been reported elsewhere on the Gulf coast of Florida from Crystal Beach Spring ( Garman et al. 2011, as Garveia franciscana ). The report of Bimeria franciscana by Joyce (1961) from Seahorse Key, on the Florida Gulf coast, is based on a misidentification of B. humilis Allman, 1877 , as noted elsewhere. Also likely misidentified are reports of the species by Fox & Ruppert (1985), as Garveia franciscana , from typically high salinity areas in coastal South Carolina. The species is regarded as an estuarine endemic, with a reported bathymetric range of 0–5 m ( Calder & Cairns 2009).

Reported distribution. Gulf coast of Florida. Crystal Beach, Crystal Beach Spring ( Garman et al. 2011: 71, as Garveia franciscana ).

Elsewhere in western North Atlantic. USA: Virginia, Hampton Roads, Fort Wool ( Clarke, 1882: 136).— USA: Massachusetts, Woods Hole + Buzzard’s Bay ( Hargitt 1909: 371, 372; Fraser 1912a: 41).— Canada: New Brunswick, Miramichi Bay ( Fraser 1926: 212).— USA: Louisiana coast ( Fraser 1943: 86, as Bimeria tunicata ).— USA: tributaries of Chesapeake Bay ( Fraser 1944: 55; 1945: 21, as Bimeria tunicata ; Cory 1967: 79, as Bimeria franciscana ; Calder & Brehmer 1967: 153, as Calyptospadix cerulea ; Cory & Nauman 1969: 215, as Bimeria franciscana ; Calder 1971: 39, as Garveia cerulea ; 1971: 40, as Garveia franciscana ; McLean 1972: 229, as Bimeria franciscana ; Andrews 1973: 231, as Garveia franciscana (= Bimeria ).— USA: coast of Louisiana and Texas ( Deevey 1950: 335; 1954: 269; both as Bimeria franciscana ).— USA: Louisiana, Lake Pontchartrain ( Crowell & Darnell 1955: 516, as Bimeria franciscana ; Poirrier & Mulino 1977: 15, as Garveia franciscana ).— USA: Mississippi, Mississippi Sound, most abundant hydroid observed ( Fincher 1955: 91, as Bimeria tunicata ).— USA: Delaware Bay ( Watling & Maurer 1972: 646, as Garveia franciscana ; Smedes & Hurd 1981: 1568, as Garveia franciscana ).— USA: Texas, Galveston Bay ( Defenbaugh 1972: 387, as Bimeria franciscana ; Defenbaugh & Hopkins 1973: 49, as Bimeria franciscana ).— Colombia: Ciénaga Grande de Santa Marta ( Wedler 1973: 32; Palacios 1979: 114; Bandel & Wedler 1987: 39, as Garveia cerula ).— USA: North Carolina, Pamlico River estuary ( Dean & Bellis 1975: 6, as Garveia cerulea ).— USA: South Carolina, estuaries ( Calder & Hester 1978: 89, as Garveia franciscana ).—? USA: South Carolina, Folly River + Breach Inlet, jetties + Beaufort area, pilings and jetties ( Fox & Ruppert 1985: 162, 167, 219, as Garveia franciscana ).— USA: Virginia, James River, oyster reefs ( Larsen 1985: 800, as Garveia franciscana ).— Venezuela: Lake Maracaibo (de Rincon & Morris 2003: 17, as Garveia franciscana ).—Caribbean Sea ( Wedler 2017b: 23, figs. 7, 8, as Garveia franciscana ).

Figures

FIGURE 2. a, Bimeria humilis: colony with two hydranths, Fort Myers Beach, ROMIZ B4330. Scale equals 0.2 mm. b, Bougainvillia rugosa: part of colony with hydranth and medusa bud, Sanibel Island, ROMIZ B4333. Scale equals 0.2 mm. c, Bougainvillia rugosa: newly liberated medusa from same hydroid, ROMIZ B4333. Scale equals 0.1 mm. d, Bougainvillia rugosa: 3-day-old laboratory-raised medusa from same hydroid, ROMIZ B4333. Scale equals 0.1 mm. e, Calyptospadix cerulea: part of hydrocaulus with branches, pedicels, hydranths, and a female gonophore, Caloosahatchee River at Fort Myers, ROMIZ B4340. Scale equals 0.3 mm. f, Amphinema sp.: hydranth and pedicel, Captiva Island, ROMIZ B4338. Scale equals 0.2 mm. g, Amphinema sp.: hydranth and pedicel, Captiva Island, ROMIZ B4338. h, Eudendrium carneum: hydranth and pedicel, Sanibel Island, ROMIZ B4343. Scale equals 0.2 mm. i, Eudendrium carneum: part of female colony with encapsulated embryos, Sanibel Island, ROMIZ B4344. Scale equals 0.4 mm.