# Haleciidae

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**Haleciidae** is a [family](/source/Family_(taxonomy)) of [hydrozoans](/source/Hydrozoa). Their [hydroid](/source/Hydroid_(zoology)) colonies emerge from a creeping [hydrorhiza](/source/Hydrorhiza) and usually form upright branching colonies, although some species' colonies are [stolonal](/source/Stolon). Their [gonophores](/source/Gonophores) are typically [sporosacs](/source/Sporosac), growing singly or bunched into a [glomulus](/source/Glomulus). They remain attached to the hydroids or break off to be passively drifted away; in a few, the gonophores are naked.[1]

Some enigmatic actively swimming [medusae](/source/Medusa_(biology)) have been tentatively placed in this family as a kind of "[wastebin taxon](/source/Wastebin_taxon)". Should their associated hydroids turn out to belong elsewhere, they are to be moved to that family and genus. The relationships of this fairly small but distinctive [radiation](/source/Evolutionary_radiation) to other families of Leptothecata are not well understood at present. However, the family [Lovenellidae](/source/Lovenellidae), often turn out to contain the hydroid stage of medusae formerly placed in the family Haleciidae.

## Description

The shallow, usually even-rimmed [hydrothecae](/source/Hydrotheca) are sessile or borne on a [hydrophore](/source/Hydrophore_(zoology)); their bottom is formed by a [concentric](/source/Concentric) [diaphragm](/source/Diaphragm_seal), with a row of small knobs [distally](/source/Anatomical_terms_of_location#Proximal_and_distal) to it. They are so small in height as to lack an [operculum](/source/Operculum_(animal)), but are maintained and repaired throughout the individual animal's life. The [hydranths](/source/Hydranth) much exceed the hydrothecae in size and are quite sturdy. Their [endoderm](/source/Endoderm) consists of a [proximal](/source/Proximal) digestive and a distal non-digestive section. The [tentacles](/source/Tentacles) of some but not all carry webbing between them; likewise, the presence of [nematophores](/source/Nematophore), [nematothecae](/source/Nematotheca) and [nematodactyls](/source/Nematodactyl) varies throughout this family.[1]

## Genera

Two [genera](/source/Genera) are currently recognized:[2]

- *[Halecium](/source/Halecium)* Oken, 1815
- *[Nemalecium](/source/Nemalecium)* Bouillon, 1986

## Footnotes

1. Schuchert (2005)

1. ["WoRMS - World Register of Marine Species - Haleciidae Hincks, 1868"](http://www.marinespecies.org/aphia.php?p=taxdetails&id=1608). *www.marinespecies.org*. Retrieved 2018-03-01.

## References

- Schuchert, P. (2011). "Haleciidae Hincks, 1868". 1608. Retrieved 2011-12-28.
- (2005): [The Hydrozoa Directory](http://www.ville-ge.ch/mhng/hydrozoa/hydrozoa-directory.htm) – [Haleciidae](http://www.ville-ge.ch/mhng/hydrozoa/lepto/conica.htm#haleciidae). Retrieved 2009-APR-10.

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Adapted from the Wikipedia article [Haleciidae](https://en.wikipedia.org/wiki/Haleciidae) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Haleciidae?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.