| Summary: | Cryptobenthic fishes (CFs) occupy a critical functional group in the trophodynamics of their respective ecological system. The percomorph suborder Blennioidei encompasses ~900 species in size families of mostly tropical and warm temperature marine fishes. The most well-studied of these families are the combtooth blennies (f: Blenniidae) comprising 58 genera and 401 species. Recent decades have seen a resurgence of interest in blenny phylogenetic relationships and the evolutionary mechanisms driving their high diversity, diverse ecology and ability to invade new habitats, and changing biogeographic landscapes. To address inquiries into these topics, some organisms may serve as models which require robust captive-breeding protocols. Blennies exhibit many traits (i.e. ease of culture, adaptability to captive conditions, fecund demersal spawning, and immediate exogenous feeding) that qualify them as a potential model group for studying marine fish ecology, biogeography, and mechanisms of diversification including speciation. In this study, the Florida blenny (Chasmodes saburrae) was cultured to establish reliable larviculture protocols for combtooth blennies and document early development to improve culture productivity. We sampled a complete larval growth series (n = 115; 1 – 21 dph) to determine allometric growth patterns of 11 morphometric characters and described ontogeny based on assigned intervals of development including changes to gape morphology to improve feeding regimes. All but one morphometric character followed a positive allometric increase after hatching and featured at least one inflection point of allometric growth rate change corresponding to phenotypic changes during notochord flexion or preparation for the completion of metamorphosis and settlement. Maximum gape size (SG) was calculated and used to estimate an optimal feeding based on size (SL) and age (dph) at first feeding of food item size class. During larviculture efforts of other combtooth species, specimens of an unidentified Hypleurochilus blenny (n = 11) previously unreported in the Gulf of Mexico (GoM), was collected on Galveston Island, TX. These specimens, along with others of the same species collected from offshore platforms in Louisiana, were included in a phylogenetic review of with seven Hypleurochilus species native to the northwest Atlantic and GoM. A molecular-taxonomic approach was applied involving phylogenetic tree reconstructions, species delimitation methods (GMYC & BPP) using four nuclear genes and mtDNA cytochrome oxidase subunit I (COI) along with morphological comparison and principal component analysis (PCA) of 13 morphometric characters. Sequenced COI revealed a ~5.4% divergence from congeners and high delimitation support (posterior probability = 1.0 for BPP) for the undetermined species. The species is distinguished from congeners by coloration, snout length, laterosensory pore structure, and density of cephalic sensory pores. We recognize this unreported species as a unique lineage but cannot confirm taxonomic identity at the species level due to a lack of comparative material from congeners not included in this study, specifically those of the oyster blenny (H. aequipinnis). This species shares diagnostic traits and superficial similarities to H. aequipinnis; thus, we designate this species to H. cf. aequipinnis until comparative study confirms identity. These findings highlight the importance of continued research into larviculture methodologies and development of model organisms and the need for ongoing genetic and biodiversity inventories on coral reefs and artificial structures, particularly as natural reef habitat is increasingly under threat and artificial habitats grow in number and ecological value.
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