Species detected from eDNA analysis with ObiTools
In the Willemstad area, eDNA analysis detected a total of 33 taxa
assigned to species level, 47 assigned to the genus level and 44 to the
family level (Table S1). Among these, 7 species, 8 genera and 7 families
were unique to this area. Those species, genera and families included
typical demersal species of shallow coastal waters such as the
Albulidae, Gerreidae, Elopidae associated to sand soft bottoms and
Achiridae, Eleotridae associated with mud soft bottoms and brackish
waters (Table S1). In Valentijnsbaai area, we detected a total of 36
taxa assigned to species level, 50 assigned to the genus level and 41 to
the family level (Table S1). Among these, 11 species, 8 genera and 4
families occurred exclusively in this area. Among those exclusive
species, genera and families, two families were pelagic, Istiophoridae
and Myliobatidae. The two remaining families were Moringuidae and
Aetobatidae, comprised of demersal species associated with coastal
ecosystems such as reefs and estuaries exclusively present in the area
– including Moringua edwardsi and Aetobatus narinari ,
respectively (Table S1). In both areas, we detected the presence of
species from the families Gobiidae and Apogonidae, which include the
majority of crypto benthic species, an important component of reef
systems (Brandl et al. 2018). One filter did not yield sufficient DNA
for reliable analyses and we removed it. The eDNA analyses are presented
for the 19 remaining filters.
Underwater visual census (UVC) at the stations in front of Willemstad
recorded a total of 30 families, 56 genera and 99 species. Among the
species in common with both methods, reef associated species such as theHalichoeres spp or Chromis multilineata were recorded by
UVC and eDNA, while typical crypto benthic species such asPhaeoptyx conklini, P. pigmentaria and Priolepis hipoliti ;
and pelagic species such as Carcharhinus longimanus orAcanthocybium solandri or coastal species such as Erotelis
smaragdus and Mugil rubrioculus were only detected by eDNA. The
detection of those species by eDNA is supported by the known occurrence
of those species in Willemstad based on species range maps of the
species in the Caribbean region (Supplementary Table 1). At the genus
level, eleven detected genera were common in both methods and 16 were
detected exclusively with eDNA. At the family level, nine detected
families were common in both methods and nine families were detected
exclusively with eDNA. Some reef families such Gobiidae, Labridae and
Pomacentridae were recorded by both UVC and eDNA, while typical pelagic
such as Clupeidae, Myctophidae and Neoscopelidae and demersal families
such as Eleotridae and Mugilidae were detected by eDNA. In
Valentijnsbaai area, UVC recorded a total of 33 families, 59 genera and
97 species. Reef associated species such as the Halichoeres sppor Bodianus rufus were recorded by both UVC and eDNA, while
typical crypto benthic species such as Elacatinus horsti ,Lophogobius cyprinoides and Oxyurichthys stigmalophius ; or
classic reef top predators such as Carcharinus perezii , were only
detected by eDNA. At the genus level, nine detected genera were common
in both methods and 19 were detected exclusively with eDNA. At the
family level, nine detected families were common in both methods and
nine families were detected exclusively with eDNA. Some reef families
such Apogonidae, Gobiidae and Labridae were recorded by both UVC and
eDNA, while typical pelagic families such as Carcharhinidae, Clupeidae
and Myctophidae were detected by eDNA.