Acryptolaria normani Nutting, 1927

Peña Cantero, Álvaro L. & Marques, Antonio C., 2004, Redescription Of Acryptolaria Normani Nutting, 1927, Junior Synonym Of The Western Pacific Species Zygophylax Tizardensis Kirkpatrick, 1890 (Cnidaria: Hydrozoa: Lafoeidae), Raffles Bulletin of Zoology 52 (1), pp. 1-6 : 1-4

Acryptolaria normani Nutting, 1927

( Figs. 1 , 2A, B ; Table 1)

Acryptolaria normani Nutting, 1927: 209 , Pl. 41 Figs. 1-2 .

Material examined. – Holotype - numerous stem fragments up to 27 mm long. United States National Museum ( USNM 5413 ), Sta. 5413, 10º10’35’’N 124º03’15’’E, between Cebu and Bohol islands ( Philippines), 42 fms (76 m), coll. Albatross Expedition, 24 Mar.1909.

Description. – Stem erect, polysiphonic ( Fig. 1A ), occasionally branched. Apophysis and nodes absent in main tube and hydrocladia. Accessory tubes with scattered tubular nematothecae ( Fig. 1B ). Hydrocladia unforked, alternate, arising in one plane from main tube at almost 90º ( Fig. 1A ). Hydrothecae alternately arranged in one plane ( Fig. 1A ). Hydrotheca completely free, pedicellate, separated from pedicel by strongly developed diaphragm ( Figs. 1E, F , 2A, B ). One nematotheca on each side of hydrothecal pedicel ( Figs. 1 D-F, 2B). Pedicel of basal hydrotheca deprived of nematothecae ( Figs. 1C , 2A ); corresponding pair of nematothecae on hydrocladium, just above pedicel insertion ( Figs. 1C , 2A ).

Hydrotheca tubiform, upwardly directed, approximately straight up to basal two-thirds, then strongly curved abcaudally at distal third ( Figs. 1E, F , 2A, B ). Hydrothecal adcauline wall convex, but clearly divided into two parts by a pronounced concave invagination ( Figs. 1F , 2A, B ), internally corresponding to a well-developed adcauline pseudodiaphragm ( Fig. 2A ): basal portion slightly convex, wall somewhat lying on adjacent tube; distal portion markedly convex, forming a kind of hump just above invagination, and strongly bent outwards ( Figs. 1E, F , 2A, B ). Abcauline hydrothecal wall mainly straight or slightly convex basally, turning abruptly outwards at distal part. Hydrothecal aperture circular, rim even and slightly flared, parallel to long axis of hydrotheca or slightly tilted downwards or upwards ( Figs. 1E, F , 2A, B ). Some hydrothecae with up to seven renovations.

Cnidome consisting of microbasic mastigophores in two size classes.

Hydranth apparently without abcauline caecum ( Fig. 1E ).

Remarks. – There is no record or reference for Acryptolaria normani since its original description by Nutting (1927: 209, Pl. 41 Figs. 1-2 ). The study of the type material has proved the incorrect assignment of this species to the classical concept of Acryptolaria or even Lafoeinae (e.g., Calder, 1991), as shown by several features: the presence of a hydrothecal diaphragm, the pedicellate and completely free (though sometimes lying on the adjacent tube wall) hydrotheca, and the presence of nematothecae. Such a set of characters is typical of the subfamily Zygophylacinae , more precisely of the genera Abietinella Levinsen, 1913 , and Zygophylax Quelch, 1885 . However, since the presence of an operculum is characteristic of Abietinella (cf. Peña & García Carrascosa, 1993), a structure absent in the holotype of A. normani , the species is unambiguously considered referable to Zygophylax (reproductive characters, such as the non-organized coppinia, may also differentiate the two genera, but reproductive structures are not present in the holotype).

A closer comparison with the known species of Zygophylax has shown that A. normani is conspecific with Zygophylax tizardensis Kirkpatrick, 1890 , originally described from the China Sea and later recorded from neighbouring areas. The shape of the hydrotheca in Kirkpatrick’s species is characteristic, making it easily recognizable. It is the same shape we found in the type material of A. normani . Still, as stated by Hirohito (1995: 150), “the remarkable feature of this species [ Z. tizardensis ] is the presence of an additional diaphragm in the middle of intrathecal wall of the hydrotheca besides the normal diaphragm at the base”, a feature also present in the type material of A. normani .

According to Nutting (1927: 209) the hydrothecae are “adnate to the branch for most of their length up to the bend, but those on the tips of the colony are free for a considerable part of their length”. Nutting’s figures also show hydrothecae adnate to the branches in most of their adcauline length. He overlooked the presence of an adcauline pseudodiaphragm and the regular pattern of a pair of nematothecae on the hydrothecal pedicels. The study of the type material of A. normani has shown that Nutting’s (1927) original description and figures are incorrect, obscuring its taxonomical position and making it difficult to assign the species to Zygophylax .

Figures

Fig. 1. Acryptolaria normani Nutting, 1927 (= Zygophylax tizardensis Kirkpatrick, 1890). A, general appearance of a fragment of stem with hydrocladia and hydrothecal arrangement (note the presence of a broken secondary stem); B, cauline nematothecae; C, pedicel of first, basal, hydrotheca (note the absence of nematothecae); D, nematotheca of hydrothecal pedicel; E-F, hydrothecae.(All photographs from holotype).

Fig.2. Acryptolaria normani Nutting, 1927 (= Zygophylax tizardensis Kirkpatrick, 1890):A, origin of hydrocladium showing first hydrotheca (note the absence of nematothecae on hydrothecal pedicel); B, hydrotheca. Zygophylax tizardensis: C, hydrotheca. (A, B from holotype of Acryptolaria normani; C from Stechow’s material). Scale bar: 250 m.