Species of Acryptolaria Norman, 1875 (Cnidaria, Hydrozoa, Lafoeidae) collected in the Western Pacific by various French expeditions, with the description of nineteen new species Author Peña Cantero, Álvaro L. Instituto Cavanilles de Biodiversidad y Biología Evolutiva, Universidad de Valencia / Fundación General, Universidad de Valencia, Apdo. Correos 22085, E- 46071 Valencia (Spain) alvaro. l. pena @ uv. es pena@uv.es Author Vervoort, Willem National Museum of Natural History, P. O. Box 9517, NL- 2300 RA Leiden (The Netherlands) vervoort @ naturalis. nnm. nl text Zoosystema 2010 2010-06-30 32 2 267 332 http://www.bioone.org/doi/abs/10.5252/z2010n2a5 journal article 8099 10.5252/z2010n2a5 f76e17a3-3bc3-43a8-ae33-6655aba3fa57 1638-9387 4521008 Acryptolaria tetraseriata n. sp. ( Figs 28 ; 30 ; 32K ; Table 29 ) MATERIAL EXAMINED . — Philippines . MUSORSTOM 3, stn DR 117, 12°31.2’- 12°31.3’N , 120°39.3’- 120°39.5’E , 92-97 m , 3.VI.1985 , 1 stem c. 100 mm high, holotype (MNHN-Hy.2009-0174) ; 1 incipient stem c. 13 mm high, paratype (RMNH-Coel. no. 31529). ETYMOLOGY. — The species name tetraseriata refers to the arrangement of the hydrothecae in four longitudinal rows, “tetra” being the Greek numeral four alluding to the number of series in which the hydrothecae are arranged. ECOLOGY AND DISTRIBUTION. — Acryptolaria tetraseriata n. sp. was collected at a depth of 92-97 m in the Philippine region. DESCRIPTION (BASED ON HOLOTYPE ) Main stem c. 100 mm high, very distinct, straight, pinnate, regularly giving rise at approximately the same interval to primary branches, alternately arranged in one plane, following a sub-opposite pattern ( Fig. 32K ); the first two primary branches are opposite. Primary branches also straight and roughly of same development, though slightly shorter and less developed at distal part of stem, perpendicular to main stem or slightly directed upwards, forming an angle of c. 70° with long axis of stem, but sometimes, particularly in the distal part, reaching 45°. In their turn the first-order branches give rise to short, much less developed and mostly monosiphonic, secondary branches. There may be anastomoses. Branches straight ( Fig. 28 ). Hydrothecae arranged in alternate decussate pairs, forming four longitudinal rows ( Fig. 28A ). In some secondary branches that arrangement may become lost because hydrothecae there are alternately arranged in two planes that form an angle of c. 90° with each other ( Fig. 28B ). Hydrotheca tubular, roughly fusiform ( Fig. 28 ) with a diameter slightly increasing from aperture to approximately midlength, after which it decreases slightly basally; minimum diameter at the base. Operculum frequently present. Hydrotheca strongly curved outwards, with a distinct inflection point where it becomes free. Adcauline wall adnate over half its length (adnate/free ratio 1.4), slightly convex in both adnate and free portions; abcauline wall concave. Hydrothecal aperture circular and directed outwards, either parallel to long axis of branch or slightly facing upwards; rim even but slightly everted, frequently with renovations. Hydrothecae moderately immersed into the branches, with distinctly marked “step” at the origin of the abcauline wall, affecting the communication between the interior of hydrotheca and branch which from “vertical” has become “lateral”. Large nematocysts relatively very large and fusiform ( Fig. 30 ). Coppinia not observed. REMARKS Our material is undoubtedly allied to A. tortugasensis Leloup, 1935 . There are, however, a few differences that prevent us, at present, to refer our material to that species.One of the most remarkable differences is the absence in our material of the characteristic internal abcauline perisarc cusp, in about the middle of the abcauline wall, of Leloup’s species. Although the presence of internal cusps has been demonstrated to be a variable character in certain species of other genera (e.g., Sertularella Gray, 1848 ), where those cusps are associated with the hydrothecal rim, the presence of internal cusps in species of Acryptolaria is exceptional, as it is only known in A. tortugasensis . Consequently we consider its presence an important diagnostic character. TABLE 29. — Measurements of Acryptolaria tetraseriata n. sp. from the holotype (in μm).

Range	Mean ± SD (n)
Hydrothecae
Length of abcauline wall	600-750	680 ± 53.4 (4)
Length of adcauline wall	815-950	886.3 ± 48.4 (4)
Length of free adcauline wall	290-450	382.5 ± 58.9 (4)
Length of adnate adcauline wall	490-525	503.8 ± 12.9 (4)
Ratio adnate/free adcauline wall	1.1-1.8	1.4 ± 0.3 (4)
Diameter at aperture	140-160	148.8 ± 7.4 (4)
Nematocysts
Larger group	29.5-33 × 10.5-11	31.4 ± 1.2 × 10.9 ± 0.3 (10)
Ratio	2.6-3.1	2.9 ± 0.2 (10)
Smaller group	5.2 × 2

In addition, although our material share with A. tortugasensis the subopposite branching pattern, some primary branches in Leloup’s species become much developed, acting as secondary stems, so that the degree of branching is high, whereas in our material the stem is clearly pinnate with all primary branches reaching more or less the same development. There is also difference in hydrothecal disposition, because in our material the hydrothecae form four longitudinal rows, being arranged in alternate decussate pairs, though this pattern may become less evident or even lost in the secondary branches, where the hydrothecae can be alternately arranged in two planes making a right angle and form only two longitudinal rows of hydrothecae as also happens in A. tortugasensis . Although they agree in the general shape and size of both hydrothecae and nematocysts, there are slight differences in these aspects too: the nematocysts in our material are slightly longer and the hydrothecae have a distinctly longer free adcauline part (cf. Table 31 ). In our material the abcauline hydrothecal wall is smoothly concave but in A. tortugasensis there is a slightly marked inflection point near the abcauline cusp, the hydrotheca being more abruptly directed outwards. Finally, there are also biogeographical reasons to keep both species separated, since A. tortugasensis is known from Tortugas , Florida , USA . FIG. 28. — Acryptolaria tetraseriata n. sp. , from MUSORSTOM 3 stn DR 117, branch fragments showing hydrothecal arrangement and hydrothecae. Scale bar: 250 μm. TABLE 30. — Measurements of Acryptolaria undulata n. sp. from the holotype (in μm).

Range	Mean ± SD (n)
Hydrothecae
Length of abcauline wall	1600-1700	1650 ± 40.8 (4)
Length of adcauline wall	1830-1870	1850 ± 18.3 (4)
Length of free adcauline wall	1000-1100	1052.5 ± 42.7 (4)
Length of adnate adcauline wall	760-830	797.5 ± 28.7 (4)
Ratio adnate/free adcauline wall	0.7-0.8	0.8 ± 0.1 (4)
Diameter at aperture	280-310	295 ± 12.9 (4)
Nematocysts
Larger group	26.5-28.5 × 10.5-12	27.6 ± 0.7 × 11.2 ± 0.5 (10)
Ratio	2.3-2.7	2.5 ± 0.1 (10)
Smaller group	7.5-8 × 3.5-4

The distinct step found at the bottom of the hydrotheca is very characteristic, being only present in A. tortugasensis and in less-developed condition in A. medeae n. sp. This step sets off the abcauline hydrothecal wall from the branch, contrary to the other species of the present genus, where the basal part of the abcauline wall is either parallel to the branch or becomes gradually separated.The presence of that strong discontinuity has another important consequence. Contrary to the other species of Acryptolaria , in which the communication between the lumina of hydrotheca and branch occurs perpendicular to the long axis of branch, between the adcauline and the abcauline walls of the hydrotheca, in our material it takes place parallel to that axis, under the adcauline hydrothecal wall.