Drivers behind the diversity and distribution of a widespread midwater narcomedusa

Abstract

Narcomedusae play a key role as top‐down regulators in the midwater, the largest and most understudied biome on Earth. Here, we used ecological niche modeling in three‐dimensions (3D), ecomorphology, and phylogeny, to answer evolutionary and ecological questions about the widespread narcomedusan genus Solmissus. Our phylogenetic analyses confirmed that Solmissus incisa represents a complex of several cryptic species. Both the different genetic clades and tentacle morphotypes were widespread and often overlapped geographically‐ the main difference in their distribution and ecological niche being depth. This demonstrated the importance of including the third dimension when modeling the distribution of pelagic species. Contrary to our hypothesis, we found the modeled distribution of the Solmissus genus (n = 1444) and both tentacle morphotypes to be mostly driven by low dissolved oxygen values and a salinity of 34, and slightly by depth and temperature. Solmissus spp. were reproducing all year round, with specimens reproducing in slightly warmer waters (up to 1.25°C warmer). Our results suggest that Solmissus spp. will likely come out as climate change winners by expanding their distribution when facing ocean deoxygenation and by increasing their reproduction due to global warming. However, because most available midwater data comes from the northern Pacific, this sampling bias was undoubtedly reflected in the output of our ecological niche models, which should be assessed carefully. Our study illustrated the value of online databases including imagery and videography records, for studying midwater organisms and treating midwater biogeographic regions as 3D spaces.

Jellyfish in Hong Kong: a citizen science dataset

“…(5) For a submission reported on social media, the HKJP principal investigator asks for as much information as possible about the observed jellyfish (such as time, date, and location) and permission for use. (6) Observation data from all three sources is recorded into an Excel spreadsheet in English. A total of 1,020 usable observations have been recorded.…”

“…Ensuring accurate photographs is necessary for verification of identification. When these photographs are accessible in online databases, they can be used to test hypotheses in biology, ecology, and niche modeling [ 6 ] . Usable observations were identified to the lowest taxonomic level and verified by the HKJP principal investigator with reference to the literature primarily [ 6 – 9 ] .…”

Pan‐Arctic distribution modeling reveals climate‐change‐driven poleward shifts of major gelatinous zooplankton species

“…Moreover, twodimensional species distribution models average environmental variables over depth layers, resulting in biased results (Duffy and Chown 2017), particularly when studying midwater taxa. Recently, more marine species distribution modeling studies are carried out in three dimensions (i.e., longitude-latitude-depth), including case studies of widespread epipelagic or midwater (e.g., Bentlage et al 2013;Verhaegen et al 2023) jellyfish outside the Arctic Ocean. Despite the wide application of such studies worldwide, only 3% of species distribution modeling studies were devoted to the Arctic Ocean and none of these focused on the distribution of gelatinous zooplankton (Robinson et al 2017).…”