Redescription Of Acryptolaria Normani Nutting, 1927, Junior Synonym Of The Western Pacific Species Zygophylax Tizardensis Kirkpatrick, 1890 (Cnidaria: Hydrozoa: Lafoeidae)
Author
Peña Cantero, Álvaro L.
Author
Marques, Antonio C.
text
Raffles Bulletin of Zoology
2004
52
1
1
6
journal article
10.5281/zenodo.10081418
2345-7600
10081418
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
).
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.
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
.