Sertularella sp.

Cantero, Álvaro Luis Peña, 2024, Fig. 4 in Positive association between PTN polymorphisms and schizophrenia in Northeast Chinese Han population., Zoological Studies 63 (17), pp. 141-149 : 17

Sertularella sp. ( Fig. 9 G−J)

Material examined: Stn 63, five stems up to 8 mm high, without gonothecae, growing on Nemertesia macquariensis sp. nov. ( NIWA 144258).

Description: Monosiphonic stems with up to six hydrothecae. Stems unbranched or with only one lateral branch with up to two hydrothecae. Stems divided into long internodes by slightly marked oblique nodes; stem internodes linear, branch internodes in zigzag. Perisarc of internodes finely longitudinally striate.

Hydrothecae arranged alternately in one plane, flask-shaped, outwardly curved. Adcauline wall adnate to internode for about half its length; free part slightly convex, with two slightly marked undulations; adnate part straight or slightly convex. Abcauline wall straight, but outwardly curved in distal part. Rim of hydrothecal aperture with four equal cusps separated by shallow embayments.

Measurements (in µm): Internodes: length 1240−1600, diameter at hydrothecal base 180–220. Hydrotheca: abcauline length 370−410, free adcauline length 250−270, adnate adcauline length 250−330, adcauline length 500−580, diameter at aperture 200−220, diameter at diaphragm 100−120, maximum diameter 250−270.

Remarks: The present species differs from all the species of Sertularella Gray considered by Galea et al. (2017) in their revision of the genus from southern South American and sub-Antarctic waters. It belongs to the group of species with hydrothecae bent outwards, but it differs from all of them primarily by the size of the hydrotheca, which is smaller in the present material, but also by having long stem internodes arranged in a straight line. Some species in this group have polysiphonic stems and unique branching patterns. However, making direct comparisons could be misleading because the material studied here (monosiphonic stems, unbranched, or with only one lateral branch with up to two hydrothecae) may represent incipient, rather than well-developed stems. Further distinctions involve the precise shape of the hydrotheca, the adnate/free proportions of the adcauline hydrothecal wall, and the presence of internal hydrothecal cusps. Consequently, even when the material studied differs from those species in one or a combination of these characteristics, the scarcity of the available material and its infertile condition make it more reasonable not to assign a specific name to this material.

Ecology and distribution: Sertularella sp. was collected from Seamount 6, north of Macquarie Island, at depths between 350 and 560 m.

Figures

Fig. 9. Tulpa tulipifera (Allman, 1888): A, hydrotheca and pedicel; B, distal part of hydrotheca showing aperture; C, incomplete gonotheca. Calamphora quadrispinosa Watson, 2003: D, hydrotheca; E, distal part of hydrotheca showing aperture; F, gonotheca. Sertularella sp.: G, stem; H−I, stem fragments showing hydrothecae and origin of branch; J, fragment of stem showing longitudinal striation. Scale bars: A, G = 3 mm; B−F, H−I = 200 μm; J = 100 μm.