Leptogorgia martirensis, Hernández & Gómez-Gutiérrez & Sánchez, 2021

Hernandez, Osvaldo, Gomez-Gutierrez, Jaime & Sanchez, Carlos, 2021, Three new species of the sea fan genus Leptogorgia (Octocorallia, Gorgoniidae) from the Gulf of California, Mexico, ZooKeys 1017, pp. 1-20 : 1

Leptogorgia martirensis sp. nov. Figures 1 , 4 , 5 , 8C, D

Material examined.

Holotype. NMNH-1638556: dry, Cueva Refugio, San Pedro Mártir Island, Sonora, Mexico (28°22.297'N, - 112°19.040'W), 1 m depth, 16 July 2010, collector Carlos Sánchez. Paratypes. NMNH-1638557: dry, Cueva Refugio, San Pedro Mártir Island, Sonora, Mexico (28°22.297'N, - 112°19.040'W), 1 m depth, 16 July 2010, collector Carlos Sánchez; NMNH-1638558: dry, Cueva Refugio, San Pedro Mártir Island, Sonora, Mexico (28°22.297'N, - 112°19.040'W), 1 m depth, July 16, 2010, collector Carlos Sánchez; NMNH-1638559: San Pedro Mártir Island, Sonora, Mexico (28°22.818'N, - 112°18.4422'W), 20 m depth, 16 July 2010, collector Carlos Sánchez.

Type locality.

Cueva Refugio, San Pedro Mártir Island, Sonora, Mexico is one of the furthest offshore islands in the Gulf of California (part of midriff islands at the upper Gulf) where volcanic rocky reefs predominate. San Pedro Mártir Island is a UNESCO "Islas del Golfo de California" Biosphere Reserve (Fig. 1 ).

Holotype colony description.

A yellow colony with bushy and dense growth with multiple and irregular brownish lines (Fig. 4A ). The colony is 6.1 cm in length and 8.1 cm in width. The holdfast is irregular, 14 mm × 11 mm from which the short main stem rises (2 mm length, 4 mm diameter). The colony has four main branches up to 11 mm length and 3 mm diameter. The main branches subdivide into multiple secondary branches (up to 31 mm length, 2 mm diameter). Terminal twigs are flat and short (12 mm length, 2 mm width) with acute ends. The general pattern of upward ramification is lateral at 45° angle. Polyp mounds are oval and prominent, forming one or two rows at each side of the branches with 0.5 mm height, 2 mm length, and 1 mm width with elongated calyces. The colony has several specimens of unidentified dried ophiuroids (<2 mm oral disc diameter) attached to the branches (Fig. 4A ).

Holotype sclerites.

The coenenchymal sclerites are exclusively capstans (Figs 4B , 5A ). There is no evidence of other types of sclerites being present in any other section of the colony. The capstans reach 0.05 mm long and 0.03 mm wide (Fig. 5A ), their color is pale yellow, pink, red or bicolor yellow-red, but the predominant color is pale yellow (90%). The anthocodial sclerites are lobed rods with acute or blunt ends up to 0.1 mm length and 0.03 mm width in the center (Fig. 5B, C ). They are bicolor white-red, red, orange or white. The red chromotype is predominant (70% of observed colonies) (Fig. 4B ).

Morphological variations.

Leptogorgia martirensis sp. nov. colonies show three chromotypes: purple, yellow and brown (Figs 4A , 8C, D ). The colony color depends on the proportion of the dominant color of the coenenchymal sclerites, but in a few cases the colonies show a brown chromotype when the color proportion of sclerites is approximately 50% purple and 50% yellow.

Diagnosis.

The colony growth, size and polyp mounds of Leptogorgia martirensis sp. nov. are similar to those of Leptogorgia aequatorialis Bielschowsky, 1929, Leptogorgia obscura and Leptogorgia parva . However, these three species each have only one chromotype (purple, pink, and orange, respectively), and all these species have spindles in their coenenchyme up to 0.1 mm length, while L. martirensis sp. nov. has three chromotypes and no spindles in the coenenchyme.

Habitat and distribution.

The micro-endemic Leptogorgia martirensis sp. nov. is only recorded in rocky shallow waters (up to 10 m depth), and low abundance, at San Pedro Mártir and San Esteban Islands, Sonora. The islands are located in the northern Gulf of California (as part of the Cortez Province according to Brusca and Wallerstein 1979, Hasting 2000), and are the most isolated islands in the gulf (Fig. 1 ). The Cortez Province is associated with the lowest winter sea superficial temperature (SST 15 °C), the widest annual range of SST (15-30 °C), high marine productivity, and harbor a unique macroinvertebrate community, dominated by endemic octocorals of the genus Muricea ( Ulate et al. 2016). Leptogorgia martirensis sp. nov. shares its habitat with Muricea austera Verrill, 1869, Muricea plantaginea (Valenciennes, 1846), Muricea spp., Psammogorgia teres Verrill, 1868, and Eugorgia excelsa Verrill, 1868.

Etymology.

Leptogorgia martirensis sp. nov. takes its name from the collection site San Pedro Mártir Island.

Figures

Figure 4. Leptogorgia martirensis sp. nov. A holotype NMNH- 1638556 B anthocodial and coenenchymal sclerites.

Figure 5. Leptogorgia martirensis sp. nov., Scanning Electron Microscopy images of coenenchymal sclerites from the holotype NMNH- 1638556 A capstans B rod lateral view C anthocodial rod sclerites.

Figure 8. Three new species of sea fans, colonies in situ, underwater images A Leptogorgia iridis sp. nov., San Juanito Island, Piedra El Morro, Islas Marias Archipelago, 10 m depth, 23 November 2010, a deep purple colony, at the base a small red wine colony of Leptogorgia ena B Leptogorgia iridis sp. nov., polyps close up C Leptogorgia martirensis sp. nov., Cueva Refugio, San Pedro Martir Island, Sonora, 2 - 3 m depth, 16 July 2010 into the cave several small colonies D Leptogorgia martirensis sp. nov., colony close up E Leptogorgia enrici sp. nov., Los Choros, BC, 25 m depth, 10 July 2009, two yellow colonies, a large colony of Eugorgia multifida in the background F Leptogorgia enrici sp. nov., El Bajo Sur, Cerralvo Island, BCS, 30 m depth, 23 June 2006, white colony G Leptogorgia enrici sp. nov., polyps close up. Photographs by Carlos Sanchez.

Figure l. Map of the Gulf of California and Mexican Pacific showing collection localities of the three new species of Leptogorgia.