Halecium, Oken, 1815

Calder, Dale R., 2019, On a collection of hydroids (Cnidaria, Hydrozoa) from the southwest coast of Florida, USA, Zootaxa 4689 (1), pp. 1-141 : 72

publication ID	https://doi.org/10.11646/zootaxa.4689.1.1
DOI	https://doi.org/10.5281/zenodo.4581872
persistent identifier	https://treatment.plazi.org/id/9E4CE23A-FF8B-F107-FF03-645FFEB52857
treatment provided by	Plazi (2019-10-25 12:55:46, last updated 2024-11-26 14:23:24)
scientific name	Halecium
status

Treatment

Halecium View in CoL sp.

Figs. 19e, f View FIGURE 19

Material examined. Southwest Florida Shelf, middle shelf west of Gasparilla Island, 26°45.86’N, 83°21.44’W, 50 m, 18 July 1981, triangle dredge, one colony fragment, 3.9 cm high, without gonophores, coll. Continental Shelf Associates, ROMIZ B1594.— Sanibel Island , beach at Lighthouse Point, 26°26’58”N, 82°01’04.5”W, detached and stranded on beach, 21 March 2018, 22° C, 34.5‰, one colony, 7 cm high, with male gonophores, coll. D. Calder, ROMIZ B4381 GoogleMaps .

Remarks. These hydroids resemble the trophosomes of several species of Halecium Oken, 1815 that have been reported from the Gulf of Mexico ( Calder & Cairns 2009), including H. halecinum ( Linnaeus, 1758) , H. beanii ( Johnston, 1838) , H. sessile Norman, 1867 , H. macrocephalum Allman, 1877 , and H. bermudense Congdon, 1907 . In lacking female gonophores, the specimens cannot be reliably identified to species. Colonies were strongly polysiphonic, with alternate and predominantly pinnate side branches; hydranths bore 20+ tentacles and the cnidome comprised both pseudostenoteles (10.2–12.0 long x 5.4 – 7.0 μm wide) and microbasic mastigophores (ca. 6.0 long x 1.8 μm wide).

References

Allman, G. J. (1877) Report on the Hydroida collected during the exploration of the Gulf Stream by L. F. de Pourtales, assistant United States Coast Survey. Memoirs of the Museum of Comparative Zoology at Harvard College, 5 (2), 1 - 66. https: // doi. org / 10.5962 / bhl. title. 15852

Calder, D. R. & Cairns, S. D. (2009) Hydroids (Cnidaria: Hydrozoa) of the Gulf of Mexico. In: Felder, D. L. & Camp, D. K. (Eds.), Gulf of Mexico. Origin, waters, and biota. Vol. 1. Biodiversity. Texas A & M University Press, College Station, Texas, pp. 381 - 394.

Congdon, E. D. (1907) The hydroids of Bermuda. Proceedings of the American Academy of Arts and Sciences, 42, 463 - 485. https: // doi. org / 10.2307 / 20022242

Johnston, G. (1838) A history of the British zoophytes. W. H. Lizars, Edinburgh, 341 pp. https: // doi. org / 10.5962 / bhl. title. 110844

Linnaeus, C. (1758) Systema naturae per regna tria naturae, secundum classes, ordines, genera, species cum characteribus, differentiis, synonymis, locis. Editio decima, reformata. Laurentii Salvii, Holmiae, 823 pp. https: // doi. org / 10.5962 / bhl. title. 542

Norman, A. M. (1867) Report of the committee appointed for the purpose of exploring the coasts of the Hebrides by means of the dredge. - Part II. On the Crustacea, Echinodermata, Polyzoa, Actinozoa, and Hydrozoa. Report of the British Association for the Advancement of Science, Nottingham, 1866, 193 - 206.

Oken, L. (1815) Okens Lehrbuch der Naturgeschichte. III. Theil. Zoologie. Vol. 1. Oken, Jena, 842 pp.

Figures

FIGURE 19. a, Halecium lightbourni: part of hydrocaulus with hydrothecae, Fort Myers Beach, ROMIZ B4377. Scale equals 0.1 mm. b, Halecium nanum: stolon with hydrocaulus and two hydrothecae, Sanibel Island, ROMIZ B4378. Scale equals 0.05 mm. c, Halecium tenellum: part of colony with a hydrotheca, Southwest Florida Shelf, ROMIZ B4379. Scale equals 0.05 mm. d, Halecium tenellum: part of colony with renovated hydrothecae, Southwest Florida Shelf, ROMIZ B4379. Scale equals 0.2 mm. e, Halecium sp.: part of a branch with three hydrothecae, Sanibel Island, ROMIZ B4381. Scale equals 0.1 mm. f, Halecium sp.: part of a branch with a hydrotheca, Southwest Florida Shelf, ROMIZ B1594. Scale equals 0.1 mm. g, Nemalecium lighti: part of colony with five hydrothecae, Fort Myers Beach, ROMIZ B4419. Scale equals 0.2 mm. h, Nemalecium lighti: two internodes, with hydrothecae, Fort Myers Beach, ROMIZ B4419. Scale equals 0.1 mm. i, Thyroscyphus marginatus: part of colony with three hydrothecae, Sanibel Island, ROMIZ B4382. Scale equals 0.5 mm. j, Thyroscyphus marginatus: hydrotheca, Sanibel Island, ROMIZ B4382. Scale equals 0.2 mm. k, Thyroscyphus ramosus: part of colony with three hydrothecae, Sanibel Island, ROMIZ B4385. Scale equals 0.5 mm. l, Thyroscyphus ramosus: hydrotheca, Sanibel Island, ROMIZ B4385. Scale equals 0.2 mm.