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Liriospyris reticulata
(Ehrenberg, 1872)
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Description - Add description
Benson, 1966, p. 293-297; pl. 20, figs. 2-7:
Amphispyris toxarium Haeckel
Amphispyris toxarium Haeckel, 1887, Challenger Rept., Zool., vol. 18, p.1097, Pl. 88, fig. 7.
Fully developed tests discoidal but with irregular outline, generally with constrictions coincident with lateral bars arising from a centrally located sagittal ring and branching and anastomosing distally to form an irregular peripheral lattice with smooth surface. Incomplete tests consist of the sagittal ring with variable development of the lateral bars. Sagittal ring asymmetrical, D-shaped, its bars three-bladed in section except for a short cylindrical median bar and the proximal portion of the vertical bar; apical bar straight, vertical, with a single (in a few specimens a pair) spine arising near its distal termination extending dorsally in the sagittal plane, branching distally to form part of the peripheral lattice; apical spine extending from and collinear with apical bar generally present, of variable length, conical to cylindrical; median bar short, generally with short, thin, conical, dorsal and primary lateral spines and a short blade-like axial spine; vertical bar angulated, with a pair of downward divergent lateral spines (bars) arising from a node located at the angle of its bend, its junction with the angulated superior bar marking the maximum ventral extension of the ring and representing a node from which arises another pair of divergent lateral spines (bars) which are bisected by the short, triangular, vertical spine, the three spines in apical or basal views giving the appearance of the letter “W” (Pl. 20, fig. 3); superior bar angulated, with a pair of upward divergent lateral spines arising from a node located at its angular bend; junction of superior and apical bars represents a fourth node from which arises a pair of divergent lateral spines; the fifth node represented by the single dorsally projecting spine arising from the apical bar; the sixth node at the junction of the median and apical bars with a pair of divergent lateral spines which correspond in position to but probably do not represent the secondary lateral spines. A few specimens with five or seven nodes but generally with six. The lateral spines (bars), circular in section, arise from the lateral blades of the three- bladed ring, have an approximate radial orientation in their proximal divergent portion but curve distally and extend laterally from the ring. The peripheral latticed portion of the test developed by branching and anastomosing of the lateral spines. It surrounds the ring laterally, ventrally, and dorsally; therefore, the shortest axis of the test corresponds to the height of the sagittal ring, the longest axis is perpendicular to the sagittal plane, and the intermediate axis corresponds to the breadth (dorsal-ventral) of the sagittal ring; the median bar is, therefore, not internal but is present at the surface of the test. A few fully developed tests have lattice developed between the lateral bars as well as around the periphery. In most tests the spaces between bars are open or only with rudimentary lattice. Constrictions of test, if present, correspond in position to the lateral bars; therefore, there are generally two in the lateral outline of the test. A sagittal constriction in the dorsal and ventral periphery is generally present. In a few specimens the lateral bars join together to form complete rings.
Measurements; based on 60 specimens from stations 27, 34, and 46: height of sagittal ring 62-89 µm, maximum breadth 54-71 µm; longest axis of test (lateral) 82-326 µm, intermediate axis (dorsal to ventral) 96-251 µm, shortest axis (apical to basal dimension) 80-135 µm; length of apical spine 0-19 µm, of vertical spine 3-8 µm, of dorsal spine 0-11 µm, of primary lateral spines 1-14 µm, of median bar 12-20 µm.
Remarks. This species was identified as Amphispyris toxarium Haeckel on the basis of the presence in Haeckel's illustration (1887, Pl. 88, fig. 7) of the "W-shaped" vertical spine structure as described above. Species similar to this but lacking the vertical spine include Amphispyris thorax Haeckel (1887, p. 1096, Pl. 88, fig. 4; Popofsky, 1913, pp. 291-293, text figs. 15, 16), A. sternalis Haeckel (1887, pp. 1096-1097, Pl. 88, fig. 2), and A. costata Haeckel (1887, p. 1097, Pl. 88, fig. 3). The vertical spine may be present in these species, but in certain orientations of specimens from the Gulf it is unobservable. Without reference to Haeckel's type material the synonymy of these species cannot be determined.
This species differs from Amphispyris subquadrata and A. aff. zonarius in the presence of the "W-shaped" vertical spine structure and, more fundamentally, in that the sagittal ring is rotated 90 degrees around the lateral axis so that the median bar is in the plane of the test surface and not interior and perpendicular to it. The presence on each the dorsal and ventral sides of the sagittal ring of a distinct raised rib which is perpendicular to the sagittal plane and from which extend the lateral bars of the zygomatic ring distinguishes fully developed individuals of A. subquadrata Haeckel from this species. The sagittal ring of this species has a more pronounced asymmetry than that of A. subquadrata and the nodes from which originate the lateral bars are less symmetrically disposed. This species differs from A. aff. zonarius Haeckel in the lack of three- bladed lateral ribs and the absence of distinct cupolas.
Distribution. This species has a much greater frequency in the southern half of the Gulf than in the northern half. It is common at stations 27, 46, absent at stations 130 and all those north of 184, and is rare at the other stations. Its frequency is generally greater in the axial regions of the Gulf; therefore, it is an oceanic species whose distribution is not influenced by upwelling. Its occurrence as far north as station 184 indicates that it is to some extent cosmopolitan in the Gulf, but it prefers oceanic waters.
Haeckel reported this species from “Challenger” station 272 in the central equatorial Pacific. Its occurrence elsewhere is unknown unless the species listed in the remarks are the sane as this species. These species were reported from the central or North Pacific; Popofsky (1913, p. 292) reported A. thorax Haecke1 from the Indian and South Atlantic Oceans. This species, therefore, is at least tropical and may range into temperate regions of all seas. It has not been reported from polar latitudes.
| | Benson 1966 |
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