Revision of the genus Acryptolaria Norman, 1875 (Cnidaria, Hydrozoa, Lafoeidae)
Author
Peña Cantero, Alvaro L.
Author
Marques, Antonio C.
Author
Migotto, Alvaro E.
text
Journal of Natural History
2007
2007-03-26
41
5 - 8
229
291
http://dx.doi.org/10.1080/00222930701228132
journal article
10.1080/00222930701228132
1464-5262
4582056
Acryptolaria longitheca
(
Allman, 1877
)
(
Figures 9
,
16A
,
18B
; Table IX)
Cryptolaria longitheca
Allman 1877
, p 18
, 19, 20, Plate 13,
Figures 4
,
5
;
Clarke 1879
, p 240, 244, Plate 2
Figures 7–13
.
Material examined
Holotype
:
MCZ
45714, off Double-Headed Shot Key, 315 fathoms (
567 m
), numerous small fragments up to
15 mm
long.
Description
‘‘Hydrocaulus attaining a height of about two inches [
50.8 mm
], pinnately but not profusely branched’’ (
Allman 1877
, p 19). Presently,
type
material consisting of numerous small fragments up to
15 mm
in length. Fragment
15 mm
long belonging to basal part of stem, completely polysiphonic, slightly geniculate and with a basally flat hydrorhiza probably indicating attachment to hard substratum.
Hydrothecae alternately arranged almost in one plane, forming an obtuse angle. Hydrotheca tubular, cylindrical in the free portion, then diameter slightly decreasing to basal part. Hydrotheca strongly curved abcaulinarly; approximately half of adcauline wall adnate to internode. Free portion of adcauline wall practically straight, adnate part slightly convex. Abcauline wall concave. Hydrothecal aperture circular, directed upwards, forming an angle of ca 60
°
with longitudinal axis of branch. Rim even, sometimes with few short renovations.
Table IX. Morphometric data of the type material of
Acryptolaria longitheca
(in Mm).
Mean¡SD |
Range |
n
|
Hydrothecae |
Length of abcauline wall |
1053.6¡69.5 |
940–1144 |
10 |
Length of free adcauline wall |
548.8¡75.6 |
420–680 |
10 |
Length of adnate adcauline wall |
740.0¡27.0 |
712–784 |
10 |
Length of adcauline wall |
1288.8¡75.0 |
1180–1400 |
10 |
Ratio adnate/free adcauline wall |
1.1–1.8 |
Diameter at aperture |
254.0¡12.1 |
240–280 |
10 |
Diameter at base |
111.2¡9.4 |
100–128 |
10 |
Nematocysts |
Larger group |
22.0¡0.6X7.2¡0.4 |
21–23X6.5–8 |
10 |
Smaller group |
8.0¡0X3.3¡0.3 |
8X3–3.5 |
3 |
Figure 9.
Acryptolaria longitheca
(
Allman, 1877
)
. (A) Branch fragment showing hydrothecal arrangement; (B–D) hydrothecae. All drawings from the holotype. Scale bar: 1 mm (A); 400 Mm (B–D).
Coppinia not observed.
Remarks
All material studied by us and assigned to
A. longitheca
seems to belong to the same colony that corresponds to the
holotype
of the species. The jar in which the type material of
A. longitheca
is preserved included a small, unlabelled vial with colonies of
A. abies
.
Allman (1877
, p 19) indicated that ‘‘
Cryptolaria longitheca
is a far less profusely branched species than
C. conferta
and from this species it further differs in the pinnate disposition of its branches and in being a stronger form with larger hydrothecae. The hydrothecae, moreover, … are cylindrical throughout, presenting no diminution of their diameter towards the base as in
C. conferta
. They appear also to pass continuously into the tubes of the hydrocaulus, no distinct floor being apparent in the hydrothecae of any part of the specimen’’.
Calder and Vervoort (1998)
examined
type
material of
A. longitheca
and
A. crassicaulis
. They found nothing to warrant their separation and, consequently, considered
A. crassicaulis
conspecific with
A. longitheca
. Although we recognize similarities between the two species, we regard them as valid (see below). The material studied by these authors is similar to
A. crassicaulis
, because of the shape of the hydrothecae, softly curved abcaulinarly, and the much larger adnate proportion of the adcauline wall. In
A. longitheca
the hydrotheca is strongly curved abcaulinarly and approximately half of the adcauline wall is adnate to the internode. Unfortunately, no information concerning the cnidome of the material studied by those authors is available, and it is not possible, at present, to evaluate their identifications based on nematocyst characters.
Acryptolaria longitheca
belongs to a group of
Acryptolaria
species characterized by large hydrothecae with a long free portion of the adcauline wall, and includes
A. corniformis
,
A. crassicaulis
, and
A. operculata
(cf. Table
XV
). However, it is clearly distinguishable from these species.
Acryptolaria operculata
has much larger general dimensions (the differences between them will be discussed below, when dealing with that species).
Acryptolaria corniformis
is also a larger species with hydrothecae slightly bent abcaulinarly, forming an angle of ca 35
°
with the long axis of branch, the free portion of the adcauline wall is distinctly larger (680–930 Mm), and the larger size-group nematocysts are distinctly smaller (10–15X3–5 Mm).
Acryptolaria longitheca
has strong affinities with
A. crassicaulis
, though it has slightly larger hydrothecae, with a larger proportion of the adcauline wall adnate to the internode and with distinctly smaller larger nematocysts (14–16.5X4.5–5.5 Mm).
Clarke (1879)
recorded
Cryptolaria longitheca
from off
Tortugas
. We considered Clarke’s record as valid, because it completely agrees with Allman’s species in shape and size of the hydrothecae, and in the free proportion of the adcauline wall. Clarke found coppinia and described them as ‘‘clustered upon the upper portions of the stem of one of the finest specimens were a number of peculiar bodies … They are polygonal in form, largest at the distal end, tapering to the base, crowded so closely together that the walls of adjoining bodies are in contact throughout their length, and are provided with a small tubular orifice arising from the centre of the distal end; at the base they are connected by branching stolons’’.
Distribution
Off Double-Headed Shot Key,
567 m
(
Allman 1877
) and off
Tortugas
(25
°
339 N, 84
°
219 W)
,
181.8 m
(
Clarke 1879
),
Florida
,
USA
.