Castellanos‑Pérez et al. Helgol Mar Res (2020) 74:13 https://doi.org/10.1186/s10152‑020‑00545‑6 Helgoland Marine Research SHORT COMMUNICATION Open Access Diversity of mangrove root‑dwelling sponges in a tropical coastal ecosystem in the southern Gulf of Mexico region Pedro de Jesús Castellanos‑Pérez1 , Laura Elena Vázquez‑Maldonado1 , Enrique Ávila2* , José Antonio Cruz‑Barraza3 and Julio César Canales‑Delgadillo4 Abstract Sponges are one of the most conspicuous groups of epibionts in mangrove prop root habitats. However, with the exception of the Caribbean and the Indo‑Pacifc regions, studies focused on species diversity are lacking in other loca‑ tions that have high mangrove coverage and are relatively distant from coral reef environments. Because mangrove‑ root epibiont communities, in general, have been understudied worldwide, this research contributes to flling this knowledge gap. In this study, a total of 30 sponge species (belonging to three subclasses, 14 families and 19 genera) were recorded as epibionts on prop roots of the red mangrove Rhizophora mangle in a tropical coastal ecosystem of the Southern Gulf of Mexico. Of these, fve were new records for the Gulf of Mexico, 14 were new for the Mexican coasts of the gulf and 25 were new for the study area. Moreover, a similarity analysis based on presence/absence data of mangrove‑associated sponges reported throughout the Western Central Atlantic region revealed that the sponge assemblage from the study area was more similar to those documented in most of the Caribbean locations (Jamaica, Cuba, Martinique, Panama, Venezuela, Belize and Colombia) rather than with those of the Northeast of the Gulf of Mexico, Guadeloupe and Trinidad. This relative intra‑regional dissimilarity in the structure of mangrove‑associated sponge assemblages may be related to diferences in environmental conditions as well as taxonomic efort. The study area, unlike most of the Caribbean locations, is characterized by estuarine conditions and high productivity through‑ out the year. The inter‑site variability recorded in the composition of mangrove‑associated sponges was infuenced by a set of factors such as salinity, dissolved oxygen and hydrodynamism. This study shows the importance of exploring the mangrove‑associated sponge assemblages from diferent regions of the world as it furthers knowledge of the bio‑ diversity and global distribution of this group. Keywords: Porifera, Biodiversity, Southern Gulf of Mexico, Rhizophora mangle, Distribution Introduction conspicuous groups of epibionts [3–5], can establish Mangrove prop roots that extend into the intertidal and mutualistic relationships with mangroves [6] and have subtidal zone constitute a habitat for a wide diversity been proposed as indicators of environmental change and of sessile invertebrates [1, 2]. In these habitats, sponges mangrove epibenthic community health [4, 7]. However, (Phylum Porifera) in addition to being one of the most despite the wide distribution of these biogenic habitats in the world, most research on the mangrove-associated sponge communities has been concentrated in two main *Correspondence: [email protected] regions, the Caribbean and the Indo-Pacifc [4, 8–11]. In 2 Instituto de Ciencias del Mar y Limnología, Universidad Nacional many of these studies, high sponge species richness has Autónoma de México (Estación El Carmen), Ciudad del Carmen, Mexico Full list of author information is available at the end of the article been highlighted, and species composition was found to © The Author(s) 2020. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creat iveco mmons .org/licen ses/by/4.0/. Castellanos‑Pérez et al. Helgol Mar Res (2020) 74:13 Page 2 of 9 difer sometimes signifcantly from that of adjacent habi- Materials and methods tats (such as coral reefs and seagrass beds) [3, 12]. Sampling of sponges was conducted by snorkeling In the Gulf of Mexico region (GoM), a recent review (between March and April 2016 and in March 2019) in documented a total of 339 sponge species from diferent nine sites distributed along the Isla del Carmen, Campe- marine environments (e.g. coral reefs, seagrass meadows, che, within the Natural Protected Area Laguna de Ter- soft and rocky bottoms and mangrove stilt roots) from minos, at the Southern Gulf of Mexico (Fig. 1; Table 1). both shallow and deep waters [13]. Although there have Tese sites corresponded to tidal creeks bordered by the been some records of species associated with mangrove red mangrove R. mangle at 0.7–2.0 m depth. Tis was root habitats (Rhizophora mangle Linnaeus, 1753) in this the only mangrove species included in the study because region, these are limited to the Northeastern coasts of it is the only one in the region that develops stilt roots, the gulf [14, 15]. In the Southern/Southwestern coasts of many of which remain fully or partially submerged in the the basin (Mexican coasts of the GoM), despite eforts to understand the regional diversity of sponges, studies con- ducted there have emphasized coral reef environments Table 1 Geographical coordinates of sampling sites at Isla [e.g. 16–19, among others]. Sponge assemblages in other del Carmen, Campeche, Mexico coastal environments of this region, such as mangroves, have not been investigated so far. Sampling site Geographical coordinates Terefore, this study aims to contribute to knowledge Estero Pargo 1 18° 40′ 21.40″ N–91° 44′ 11.83″ W of the biodiversity and spatial distribution of mangrove Estero Pargo 2 18° 39′ 40.10″ N–91° 44′ 54.74″ W root-dwelling sponges in tropical coastal ecosystems of Estero Pargo 3 18° 39′ 05.83″ N–91° 45′ 31.93″ W the Southern Gulf of Mexico eco-region (SGM), particu- Estero Pargo 4 18° 38′ 41.28″ N–91° 45′ 56.59″ W larly, in one of the Mexican states (Campeche) with the Estero Pargo 5 18° 38′ 21.30″ N–91° 46′ 13.15″ W largest cover of mangrove forests [20]. Te similarity of Bahamita 18° 40′ 04.08″ N–91° 42′ 01.03″ W the sponge assemblage recorded in the study area with Cases 18° 41′ 24.06″ N–91° 40′ 42.09″ W those reported in locations in the Caribbean and in the Ensenada Grande Northeast of the Gulf of Mexico is also discussed. 18° 43′ 52.58″ N–91° 34′ 39.71″ W Estero San Julián 18° 45′ 54.42″ N–91° 31′ 34.61″ W Fig. 1 Location of the study area and sampling sites at the Isla del Carmen in the Southern Gulf of Mexico. E1 Estero Pargo 1, E2 Estero Pargo 2, E3 Estero Pargo 3, E4 Estero Pargo 4, E5 Estero Pargo 5, B Bahamita, C Cases, EG Ensenada Grande, SJ Estero San Julián Castellanos‑Pérez et al. Helgol Mar Res (2020) 74:13 Page 3 of 9 water. In each site, a linear transect of 20 m in length was ANOSIM test was used to detect signifcant diferences placed along the mangrove border, within which 30 sus- between groups [41]. At local scale, a non metric multidi- pended stilt roots of R. mangle were randomly selected. mensional scaling (nMDS) analysis was also used (using On each root, samples of sponges that were morpho- the UPGMA based on Jaccard’s similarity coefcient logically (e.g. form, color, consistency) diferent were built from the precence/absence data of species) to visu- carefully removed from the substrate by hand or using a alize the variations in sponge species composition among knife, and promptly placed individually into plastic bags the nine sampling sites. Tese analyses were done using for later taxonomic identifcation based on external char- PAST program v. 3.25 [42]. In addition to examining the acters, skeletal structure and spicule morphology and infuence of environmental variables on the distribution size [21]. Tese sponge samples were of variable size and, of mangrove-associated sponges at Isla del Carmen, a when possible, more than one specimen of each species redundancy analysis (RDA) was performed using the rda was collected. In each site, the presence/absence of each function of the vegan community analysis package [43]. sponge species was recorded. Environmental parameters In this analysis, the response variable was the presence/ such as water temperature (TE), salinity (SA), dissolved absence of the species at each of the sampling sites. Inde- oxygen (DO), sedimentation rate (SR), water transpar- pendent variables included TE, SA, DO, DE, TR, SR, RL, ency (TR), depth (DE), hydrodynamism (H), and root RC and H. After an exploratory analysis, the variables length (RL) and circumference (RC) were also recorded RL and RC were excluded from the analysis because the in each of the nine sampling sites. Temperature (T°C), infation factor of the variance was > 10. Alpha diversity salinity and dissolved oxygen (mg/L) were measured by (α–diversity) was calculated as the mean species richness a multi-parameter meter (YSI Model 63, Salinity Con- in each site and the global beta diversity (Whittaker’s ductivity Temperature, Ohio 45,387, USA) at 1 m depth. βw) for all the sampled sites sampled was determined Sedimentation rate (g dry weight m− 2 day− 1) was meas- by dividing the total species richness between the mean ured at each site with a trap system consisting of four sets alpha diversity [44].