Research Article |
Corresponding author: Carlos Sánchez ( csanchez@uabcs.mx ) Academic editor: James Reimer
© 2021 Osvaldo Hernández, Jaime Gomez-Gutiérrez, Carlos Sánchez.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Hernández O, Gomez-Gutiérrez J, Sánchez C (2021) Three new species of the sea fan genus Leptogorgia (Octocorallia, Gorgoniidae) from the Gulf of California, Mexico. ZooKeys 1017: 1-20. https://doi.org/10.3897/zookeys.1017.50619
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Three new sea fan species of Leptogorgia were discovered during multiple scuba diving expeditions along the Gulf of California coast and islands. Leptogorgia iridis sp. nov. is distributed in the southern region of the gulf (Mexican Province), inhabiting tropical rocky reefs of the Islas Marías Archipelago (Nayarit) and Bahía Banderas (Jalisco). This species has small colonies (< 7 cm height) with at least five clearly distinct chromotypes. Leptogorgia martirensis sp. nov. was found exclusively on the rocky reefs of San Pedro Mártir and San Esteban Islands located in the northern region of the Gulf of California (northern region of Cortez Province). Leptogorgia enrici sp. nov. is distributed from the south to the northern region of the Gulf of California (Cortez Province), inhabiting substrates of rocky reefs, sandy and pebbly sea floors. Comprehensive ecological diving expeditions to identify and classify octocorals in the Mexican Pacific (1995–2019) indicate that L. iridis sp. nov. and L. martirensis sp. nov. are likely to be micro-endemics and L. enrici sp. nov. is endemic to the Gulf of California, which defines their currently known biogeographic distribution ranges.
Alcyonacea, chromotypes, Cnidaria, gorgonians, microendemism, rocky reef
The family Gorgoniidae Lamouroux, 1812 includes mostly species of three genera in the eastern Pacific: Pacifigorgia Bayer, 1951 with anastomosed branching as the main diagnostic character, Eugorgia Verrill, 1868 with the presence of double disk capstans and Leptogorgia Milne Edward & Haime, 1857; which, in contrast to the previous two genera, does not have a single diagnostic genus morphological feature (
There are 30 extant Leptogorgia species recorded along the American Pacific coast, with Leptogorgia waltonae Olvera, Hernández, Sánchez & Gómez-Gutiérrez, 2018 being the latest species described in the Mexican Pacific (
Approximately 500 quantitative monitoring transects, each one covering an area of 30 m², were surveyed during extensive annual ecological expeditions located along the peninsular coast and at 25 islands of the Gulf of California (1995–2019), Islas Marías Archipelago (2010 and 2018), Bahía Banderas (2013) and Bahía Magdalena (2013–2014) (Fig.
Comparison of morphological characters of Leptogorgia iridis sp. nov., Leptogorgia martirensis sp. nov. and Leptogorgia enrici sp. nov. with fourteen other Leptogorgia nominal species distributed along the Mexican Pacific and Gulf of California of specimens collected from 2002–2016 and from other regions of the Eastern Pacific reported in
Species | Colony growth | Branching type | Terminal branches diameter | Polyp distribution rows | Polyp mound elevation | Capstan length | Spindles length | Bent spindles | Crosses | Anthocodial sclerites | Dominant sclerites | Color of colony | Bicolor colonies | Number of solid chromotypes | Bicolor sclerites | Anthocodial sclerites color | Color ring |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
L. iridis sp. nov. | planar | lb | 1–2 | 2 | slightly raised | 0.06 | 0.07 | no | 0.05 × 0.05 | rod | C | pu/y,pu, r, w, y | yes | 5 | yes | pu, r, w, y | no |
L. martirensis sp. nov | bushy | lb | 2 | 1–2 | prominent | 0.05 | no | no | no | rod | C | y, p, br | no | 3 | yes | o, r, w | no |
L. enrici sp. nov. | planar | lb | 1.5 | 1, irr | no | 0.06 | 0.11 | yes | 0.06 × 0.06 | rod | C | o, pu, y, w, y/pu | yes | 4 | no | o, y, pu | no |
L. alba | flabellate | irr/di | – | 2 | slightly raised, flat | 0.06 | 0.18 | yes | – | rod | S | w | no | 1 | no | no | no |
L. chilensis | lank, bushy | irr/di | 2.8 | spar | flat | 0.08 | 0.12 | no | 0.06 × 0.06 | Rod, biscuit | C-S | o | no | 1 | no | o | no |
L. clavata | – | pi | – | irr | slightly raised | 0.075 | 0.10 | no | – | rod | C | r | no | no | pi | no | |
L. cuspidata | bushy | irr/pd | 3.25–4 | crowd | – | 0.09 | 0.13 | yes | – | rod | C | pu/y | yes | 1 | yes | y | yes |
L. diffusa | bushy, arborescent | lb | 3 | 1–2 | prominent | 0.09 | 0.15 | yes | – | rod | S | o | no | 1 | no | o | no |
L. ena | cluster | lb | 2–3 | irr | slightly raised | 0.086 | 0.108 | no | 0.05 × 0.07 | rod-platelet | C | pu, y, pu/y | yes | 3 | yes | pu, y | no |
L. exigua | bushy | irr/pi | 3–4 | crowd | slightly raised | 0.10 | 0.13 | no | – | – | C | brr/y | no | 1 | yes | – | no |
L. filicrispa | strands | bra-str | 0.5–1 | 2 | prominent | 0.08 | 0.11 | no | – | rod | – | pi | no | 1 | no | pi | no |
L. flexilis | bushy | irr/di | 1.0–1.5 | 4–5 | flat | 0.09 | 0.09 | no | – | rod | C | r/br | no | 1 | yes | r | no |
L. labiata | flabellate | irr/pi | 2 | 4 | prominent | 0.08 | 0.1 | no | – | rod | C | pi/y | yes | 1 | yes | y | yes |
L. laxa | planar | irr/di | 1.0–1.5 | 2 | slightly raised | 0.08 | 0.18 | no | – | rod | – | w | no | 1 | no | no | no |
L. manabiensis | planar | irr/pi | 1.9 | spar | slightly raised | 0.08 | 0.14 | yes | – | rod | S | pi | no | 1 | no | no, hy | no |
L. pumila | bushy | irr/pi | 2, 3 | 2, spar | raised | 0.1 | 0.15 | yes | 0.08 × 0.06 | rod | – | pu, pi | no | 1 | no | am | no |
L. rigida | bushy, arborescent | pi | 2–3 | 3–4 | slightly raised | 0.08 | 0.12 | no | 0.04 × 0.04 | rod | C, O | pu | no | 1 | no | pi | no |
Subclass Octocorallia Haeckel, 1866
Order Alcyonacea Lamouroux, 1812
Suborder Holaxonia Studer, 1887
Family Gorgoniidae Lamouroux, 1812
Holotype.
Islas Marías Archipelago is located in the southern region of the Gulf of California, Mexico (21°25.267'N, -106°24.900'W) near the continental shelf-break about 158 km southwest of Mazatlán, Sinaloa and 106 km northwest of Bahía Banderas, Nayarit (Fig.
Colony shows lateral branching and planar growth of 7 cm height and 8.1 cm width. Holdfast is 5 mm diameter and arises the main steam 2.1 cm length and 2 mm diameter, subdividing into two main branches (Fig.
Coenenchymal sclerites of Leptogorgia iridis sp. nov. holotype are mostly bright yellow or purple and few of them are bicolor or white (Fig.
Leptogorgia iridis sp. nov. paratypes differ from the holotype in branch diameter and coloration. The morphotypes have a wide range of colorations due to the different proportion of sclerite colors and coenenchymal sclerite arrangement (Figs
Purple and red Leptogorgia iridis sp. nov. have quite similar colony shapes. Both L. iridis sp. nov. chromotypes resemble the color of Leptogorgia obscura Bielschowsky, 1929 and Leptogorgia parva Bielschowsky, 1929. However, L. obscura has small anthocodial rods with blunt ends and L. parva has anthocodial rods with conspicuous lobed margins, which are absent in L. iridis sp. nov. Additionally, L. obscura and L. parva have only one known chromotype, and their terminal branches have acutely pointed ends. In contrast, L. iridis sp. nov., has long anthocodial rods with acute ends and no lobed margins, showing up to five solid colony chromotypes and terminal branches with blunt ends.
The distribution of Leptogorgia iridis sp. nov. covers part of the Central Tropical Mexican Pacific (Mexican Province in
Leptogorgia iridis sp. nov. is named from the Latin word iridis, which means “rainbow” due to the large number of chromotypes observed in the colonies. Large numbers of chromotypes are one of the main diagnostic characteristics of this novel tropical species.
Holotype.
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.
A yellow colony with bushy and dense growth with multiple and irregular brownish lines (Fig.
The coenenchymal sclerites are exclusively capstans (Figs
Leptogorgia martirensis sp. nov. colonies show three chromotypes: purple, yellow and brown (Figs
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.
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
Leptogorgia martirensis sp. nov. takes its name from the collection site San Pedro Mártir Island.
Holotype.
San Esteban Island is part of the midriff islands at the upper Gulf of California, and is the 15th largest island in Mexico by area (40 km²), and has predominantly volcanic rocky reefs. San Esteban Island is a UNESCO “Islas del Golfo de California” Biosphere Reserve (Fig.
A bright yellow colony with planar growth and lateral branching (Fig.
The dominant type of sclerites is capstans of 0.06 mm length and 0.03 mm width (Fig.
Leptogorgia enrici sp. nov. has arborescent and planar forms of colony growth. The planar colony is the more common morphotype. Leptogorgia enrici sp. nov. has four solid colony colorations: yellow (Figs
Three new species of sea fans, colonies in situ, underwater images A Leptogorgia iridis sp. nov., San Juanito Island, Piedra El Morro, Islas Marías 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 Mártir 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 Sánchez.
The purple chromotype of Leptogorgia enrici sp. nov. is morphologically similar to the thin and planar morphotype of Leptogorgia rigida; however, both species differ completely in the form of their sclerites. The coenenchyme sclerites of L. rigida consist mainly of robust capstans with short waists, double heads and spheres (absent in L. enrici sp. nov.), while the sclerites of L. enrici sp. nov. are mainly thin capstans and long and spindle sclerites; spindles are absent in L. rigida. These two species are distributed in different habitats: L. rigida in shallow areas (<10 m depth) attached to rocky reefs, typically inhabiting areas with strong currents or wave action and even in the cracks of rocks, while L. enrici sp. nov. is found in rocky reefs, sandy or pebble beds at depths usually < 20 m depth. The morphology of L. enrici sp. nov. is similar in the type of branching and colony color to Leptogorgia chilensis (Verrill, 1868) and Leptogorgia flexilis (Verrill, 1868). However, these three species are distinct because L. enrici sp. nov. has colonies with planar growth and four solid chromotypes (yellow, orange, purple and white) and has many long spindles. Leptogorgia chilensis and L. flexilis show arborescent growth typically with branches very close to each other. Each species has a single colony chromotype (L. chilensis is orange and L. flexilis is red) and spindle sclerites are present in low proportions, with blunt tips rather than the long spindles with pointed tips observed in L. enrici sp. nov. The long and acute spindles in L. enrici sp. nov., are only comparable in size to the spindles of Leptogorgia alba and Leptogorgia manabiensis Soler-Hurtado, Megina, Machordom & López-González, 2017 (
Leptogorgia enrici sp. nov. is endemic to the Gulf of California (Cortez Province according to the biogeographic regions of
Leptogorgia enrici sp. nov. occurs in low densities scattered on the reefs (< 1 colony 100 m2) and never clustered in several colonies. Marine ecological censuses carried out during 2009, 2010 and 2018 showed L. enrici sp. nov. is distributed at the Mid-Rift Archipelago of the Gulf of California (Ángel de la Guarda, Partida, Salsipuedes, Las Ánimas, San Lorenzo, San Esteban, San Pedro Mártir, Tortuga and San Marcos) and at the coast of Baja California peninsula (Los Choros). Leptogorgia enrici sp. nov. has been collected with scuba at 40 m in the central and southern Gulf of California (Isla Danzante and Isla Cerralvo). Leptogorgia enrici sp. nov. shares its habitat with Muricea spp., Muricea plantaginea (Valenciennes, 1846), Muricea austera Verrill, 1869, Muricea fruticosa Verrill, 1869, Eugorgia aurantiaca (Horn, 1861), Psammogorgia teres Verrill, 1868, and Heterogorgia papillosa Verrill, 1870.
Leptogorgia enrici sp. nov. is named in honor of Dr. Enric Sala, a National Geographic Explorer-in-Residence actively engaged in the exploration, research, and science communication to advance ocean conservation. Enric Sala is a passionate enthusiast of marine life and the conservation of Mexican seas who actively collaborates to generate marine biodiversity knowledge. He founded and leads the National Geographic’s Pristine Seas project that has conducted 30 expeditions in the world, creating 22 no-take large marine reserve (~5 million km2 of no-fishing zones).
We discovered three new species of the genus Leptogorgia in the Gulf of California, adding biodiversity information on the Eastern Pacific Ocean. Although sea fans are the most abundant benthic macroinvertebrates in the rocky reefs of the Gulf of California (
The description of Leptogorgia iridis sp. nov., Leptogorgia martirensis sp. nov. and Leptogorgia enrici sp. nov. increases the number of nominal Leptogorgia species currently known in the Mexican Pacific to 20 (
The discovery of these three new octocoral species was possible because the highest population density of each species was found in relatively isolated marine areas with exceptionally restricted access (Islas Marías Archipelago was a federal penitentiary) or at isolated offshore islands (San Pedro Mártir Island) with access for general public only through touristic trips. However, those locations do not qualify as pristine habitats and they may already be impacted or will be impacted in the near future. The lack of research effort and the small population size of these three new Leptogorgia species explain why these species have been overlooked at the Islas Marías Archipelago and oceanic islands of the Gulf of California. The lack of knowledge of Leptogorgia enrici sp. nov. is because this species is distributed below 30–40 m deep, often on sandy-pebble sea floors where previous research efforts has been few. Our quantitative, historical, and systematic invertebrate monitoring program has been, so far, focused on fauna from rocky reefs in <20 m depth (
Leptogorgia martirensis sp. nov. has been observed and sampled only from rocky reefs from San Pedro Mártir Island (type locality) and San Esteban Island. We observed this species in low density, and only in cavities or caves formed in the island’s rocky reefs. We have been carrying out systematic scuba-diving monitoring during 2008–2019 in at least 50 locations at seven islands located close to San Pedro Mártir, providing strong evidence that, except for San Esteban Island, these islands do not harbor colonies of L. martirensis sp. nov. The distribution records of these new species compared with our ecological marine census data at extensive locations along the Pacific coast of Mexico (Breedy and Guzman 2005,
We thank Octavio Aburto (SIO-UCSD) and Exequiel Ezcurra (UC Riverside) for their facilities for the collection of invertebrates at Islas Marías Archipelago (IMA) during November 2010 and 2016. We thank scientists and crew of the liveaboard “Rocío del Mar” for their valuable help during the scuba diving collection. Instituto Nacional de Ecología (INE), Mexico, Fondo Mexicano and an anonymous donor funded the IMA research cruise. We are grateful for research collection facilities and permission to Secretaría de Medio Ambiente y Recursos Naturales (SEMARNAT) and Comisión Nacional de Áreas Naturales Protegidas (CONANP), Mexico (Oficio NUM. F00-0526). We thank Secretaría de Gobernación de México and Secretaría de Marina for their logistic facilities. Universidad Autónoma de Baja California Sur and Centro Interdisciplinario de Ciencias Marinas (Instituto Politécnico Nacional, SIP-IPN 2010–2020) provided additional financial support. This research was conducted as part of the Universidad Autónoma de Baja California Sur, Proyecto Fauna Arrecifal (UABCS-PFA). UABCS Fauna Reef Conservation Research Programs is funded by the grants: SEMARNAT-CONACYT 2004-01-445 “Biogeography and molecular systematics of sea fans and soft corals (Cnidaria: Octocorallia) in Mexico’s Pacific and the Gulf of California”; CONABIO JF190/2013 “Inventory of sessile marine life in the Pacific islands of Baja California Sur”; UC-MEXUS “An ecological and economic baseline for the Revillagigedo Archipelago Biosphere Reserve, Mexico” (2006), UABCS-SCRIPPS-CBMC “Ecological Monitoring ProMARES”, and Pristine Seas of National Geographic Society (2016). All these research projects were carried out at Revillagigedo Archipelago (2006, 2016), Islas Marías Archipelago (2010), Bahía Banderas (2013), and Gulf of California (1998–2018) expeditions. J.G.-G. is a COFAA-IPN, EDI-IPN, and SNI fellow.