Chromoplexaura cordellbankensis Williams and Breedy, 2019

Williams, Gary C. & Breedy, Odalisca, 2019, A New Species of Gorgonian Octocoral from the Mesophotic Zone off the Central Coast of California, Eastern Pacific with a Key to Related Regional Taxa (Anthozoa, Octocorallia, Alcyonacea), Proceedings of the California Academy of Sciences 65 (6), pp. 143-158 : 145

Chromoplexaura cordellbankensis Williams and Breedy , sp. nov.

Figures 2–10.

HOLOTYPE.— CASIZ 228195 ; NOAA Sample SH-18-09-017; Cordell Bank, Cordell Bank National Marine Sanctuary, CBNMS Transect-127; ca. 51 km W. of Point Reyes Peninsula (38°03′ 15.465″N 123°28′48.072″W); 100.5 m depth; 08 August 2018; ROV Beagle ( MARE) from FSV Bell M. Shimada ( NOAA); one partial specimen (missing holdfast), wet–preserved in 95% ethanol.

PARATYPES.— CASIZ 228194 . NOAA Sample SH-18-09-016; Cordell Bank, Cordell Bank National Marine Sanctuary , CBNMS Transect-127; ca. 51 km W. of Point Reyes Peninsula , California, USA (38°03′15.915″N 123°28′49.874″W); 101.6 m depth; 08 August 2018; ROV Beagle ( MARE) from FSV Bell M. Shimada ( NOAA); one partial specimen (14 mm long branch fragment), wet-preserved in 95% ethanol . CASIZ 207519 ; La Cruz Canyon , Monterey Bay National Marine Sanctuary; California, USA (35.7694°N 121.4475°W); 106.8 m depth; 28 October 2018; coll. by ROV on board FSV Bell M. Shimada ( NOAA); one whole specimen . CASIZ 207520 ; Anacapa Island , Channel Islands National Marine Sanctuary; California, USA (33.992°N 119.3722°W); 86 m depth; 31 October 2018; coll. by ROV on board FSV Bell M. Shimada ( NOAA); one specimen in two pieces.

HABITAT AND DISTRIBUTION.— Found on rugose, rocky substrata often with conspicuous vertical relief, or on rounded boulders in boulder fields ( Fig. 3 ). Distributed off the central and southern coasts of California, between 38.2° and 32.5°N latitude ( Figs. 8–9 ); at mesophotic depths between 86 and 107 m. The type locality is Cordell Bank in the Cordell Bank National Marine Sanctuary , ca. 70 miles WNW of San Francisco, California, 100 m depth .

ETYMOLOGY.— The specific epithet is derived from Cordell Bank and the Latin suffix – ensis (belonging to); referring to the region of discovery of the new species and collection of the holotype – Cordell Bank National Marine Sanctuary.

Figures

FIGURE 2. Chromoplexaura cordellbankensis sp. nov. Wet-preserved holotype, external morphology. A, D. Partial colony, scale bar = 10 mm. B. Detail of the proximal branch, scale bar = 5 mm. C. Distal apex region of the middle branch, scale bar = 5 mm. E. Apex region of the main stem, scale bar = 5 mm. F. Compound microscope view of sclerites at 100x magnification, showing yellow coloration, scale bar = 0.2 mm.

FIGURE 3. Chromoplexaura cordellbankensis sp. nov. Underwater photographs taken in situ by Remotely Operated Vehicles (ROVs), showing individual colonies of the new species (red arrows) with surrounding habitat. A. Image taken at Cordell Bank National Marine Sanctuary near the type locality, ca. 100 m depth, 8 August 2018. B. Image taken at Cordell Bank National Marine Sanctuary near the type locality, 102 m depth, 8 August 2018, with a nudibranch mollusk (Dendrodoris azineae) to the immediate left. C. Image taken at Cortes Bank, ca. 166 km west of Point Loma San Diego, 70 m in depth, 7 September 2007. D. Image taken at Cortes Bank, ca. 166 km west of Point Loma San Diego, 70 m depth, 8 September 2007. E. Image taken at La Cruz Canyon, Monterey Bay National Marine Sanctuary, 106.8 m depth, 28 October 2018. F. Image taken at Anacapa Island, Channel Islands National Marine Sanctuary, 86 m depth, 31 October 2018. Photographs courtesy of National Oceanic and Atmospheric Administration.

FIGURE 4. Chromoplexaura cordellbankensis sp. nov. Scanning electron micrographs of coenenchymal sclerites – warty spindles. Scale bar = 0.04 mm.

FIGURE 5. Chromoplexaura cordellbankensis sp. nov. Scanning electron micrographs of coenenchymal sclerites – warty spindles. Scale bar = 0.04 mm.

Figure 6. Chromoplexaura cordellbankensis sp. nov. Scanning electron micrographs of coenenchymal sclerites – radiates (top row) and various immature sclerites (middle and bottom rows). Scale bar = 0.04 mm.

FIGURE 7. Chromoplexaura cordellbankensis sp. nov. Scanning electron micrographs of polyp sclerites. Scale bar = 0.04 mm.

FIGURE 8. Map of Cordell Bank National Marine Sanctuary (central California); type locality of Chromoplexaura cordellbankensis sp. nov. (red triangle). Map adapted from National Oceanic and Atmospheric Administration (2014).

FIGURE 9. Map of the Pacific coast of the United States showing the geographical ranges of Chromoplexaura marki () and Chromoplexaura cordellbankensis sp. nov. (); arrow denotes type locality.

FIGURE 10. Scanning electron micrographs of coenenchymal sclerites. A. Chromoplexaura cordellbankensis sp. nov. (CASIZ 228194). B. Chromoplexaura marki (CASIZ 190436). C. Euplexaura sp. (CASIZ 220608). D. Swiftia torreyi (CASIZ 220958). Scale bars = 0.05 mm.