Balanodytes, Utinomii, 1950

Botha, Thomas P. A. & Griffiths, Charles L., 2021, South African Acrothoracica (Crustacea: Cirripedia), Zootaxa 4949 (1), pp. 45-78 : 66

Balanodytes sp. A

Figs 15–17

Deposited material. Holotype, SAMC-A091082 , Port Shepstone , KwaZulu-Natal, August 2017, 1 specimen in Charonia lampas shell . Paratype, SAMC-A091083 , 2 specimens, same data as holotype . Paratype, SAMC-A091084 , 1 specimen, same data as holotype (acid-treated specimen) . SAMC-A091090 , Port Shepstone , KwaZulu-Natal, 19 September 2017, 2 specimens on Mancinella capensis shells (only 1 deposited, other specimen used for dissections) .

Other records. Port Shepstone , KwaZulu-Natal, 19 September 2017, 1 specimen on Dinoplax validifossus Ashby, 1934 shell plate (not deposited, used for SEM) .

Diagnosis. Balanodytes with a well-developed, armed orificial knob, opercular bars with straight posterior processes with slightly anterior-facing spine branching off at apex.

Description. Female, length 2.1 mm and width 1.05 mm. Opercular bars 500 um long. Lateral row of large bifid teeth on opercular bar extending onto posterior processes, with several rows of smaller rosette nodules closer to opening along opercular bar (fig. 16C, D, F). Anterior end of opercular bar with large bifid tooth on each opercular bar (fig. 16C; 17B). Opercular bar with large, straight posterior processes, with small spine branching off at apex that is slightly recurved (anterior-facing) with several bifid teeth and simple spines (fig. 16D). Pronounced comb collar starts on inside of posterior processes of opercular bar, extending to its anterior end (fig. 16A, B). Several hook-like spines and setae below opercular bar. Orificial knob well-developed with setae and simple teeth (fig. 17A, B). Multifid scales and randomly-distributed setae visible along operculum (fig. 16D). Mantle with several randomly-distributed bifid teeth (fig. 16E). Lateral bars absent. Area below opercular bars purple, rest of body reddishbrown, turning light brown when preserved in alcohol (fig. 15A). Burrow opening narrow, oval-shaped (fig. 15B).

Terminal cirri consisting of four pairs, two-segmented caudal appendages with three setae (fig. 17C, D). Mouth cirri with four-segmented anterior ramus longer than four-segmented posterior ramus, both with long plumose setae (fig. 17H). Mandible with three large teeth, first upper tooth separated from other lower teeth, lower margin below third tooth with three smaller teeth with setae (fig. 17F). Maxillule with two long, cuspidate setae, notch with short setae; lower margin with numerous short, sharp setae (fig. 17G). Maxilla triangular, with long setae on exterior margin (fig. 17E). No males observed.

Hosts. Type host a hermit crab-occupied Charonia lampas from Port Shepstone. Also found in Dinoplax validifossus and Mancinella capensis .

Variation. Other specimens ranged in length from 1.65–2.5 mm (mean = 1.98 mm) and width 0.95–1.3 mm (mean = 1.05 mm). Opercular bars on average 510 um long.

Distribution. Known only from Port Shepstone (3044’38.8”S, 3027’28.7”E). Endemic to KwaZulu-Natal.

Remarks. The caudal appendages are without basal pedestals, unlike Auritoglyptes Kolbasov & Newman, 2005 and Lithoglyptes Aurivillius, 1892 . This genus contains species with posterior processes that are either straight ( B. echinoideus , B. egorovi and B. mitis ), recurved, i.e. bent posteriorly ( B. balanodytes , B. cornutus and B. scamborachis ) or decurved, i.e. bent anteriorly ( B. flexuosus , B. habei , B. stirni , B. thomasi , B. wilsoni ) ( Kolbasov & Newman, 2005; Chan, Kolbasov & Cheang, 2012; Chan, Hsieh & Kolbasov, 2014). Only B. flexuosus , B. habei and B. mitis ( taiwanus ) have a well-developed orificial knob (as does Balanodytes sp. A). Lateral bars either feeble ( B. egorovi , B. flexuosus , B. habei , B. mitis and B. scamborachis ) or absent ( B. balanodytes , B. cornutus , B. echinoideus , B. stirni , B. thomasi and B. wilsoni ). Based on this information, Balanodytes sp. A is most similar to B. flexuosus and B. mitis , but differs as it has a simple spine that branches off the posterior processes of the opercular bar (making it appear bifid, unlike B. flexuosus , where the whole posterior process is recurved) and teeth not recurved (or no teeth). Differences also exist regarding the opercular knob, as it is more developed and pronounced in Balanodytes sp. A. Moreover, differences also exist in the mandible, teeth on the opercular bar, and Balanodytes sp. A is purple, not orange in colour around the opercular area. No dwarf males were observed.

Figures

FIGURE 15. Balanodytes sp. A in a Charonia lampas shell collected at Port Shepstone, female. A—Lateral view of whole specimen, left side; B—Burrow opening.

FIGURE 16. Balanodytes sp. A from Charonia lampas from Port Shepstone. Scanning electron microscopy of external morphology of external structures, female. A—Magnified view of comb collar projections; B—Comb collar and setae on posterior part of opercular area; C—Opercular area; D—Posterior processes and spines on opercular bars; E—Bifid mantle teeth; F—Bifid and simple teeth and nodules on opercular bar. Abbreviations: cc—comb collar, ob—opercular bar, obp—posterior process of opercular bar.

FIGURE 17. Balanodytes sp. A collected from Charonia lampas from Port Shepstone. Light microscopy of mantle structures of inner body, female. A—Lateral view of whole specimen, right side; B—Lateral view of opercular area; C—Terminal cirri; D—Caudal appendage; E—Maxillule; F—Mandible; G—Maxillule and maxilla; H—Mouth cirrus.