Skeletal development in the heterocercal caudal fin of spotted gar (lepisosteus oculatus) and other lepisosteiformes

Abstract

The present work highlights the power and importance of ontogenic studies and provides bases for future evolutionary and morphological investigations on actinopterygians fins. Developmental Dynamics 247:724-740, 2018. © 2018 Wiley Periodicals, Inc.

Evolution of caudal fin ray development and caudal fin hypural diastema complex in spotted gar, teleosts, and other neopterygian fishes

“…We also found that in more developed gar individuals, the plates of connective tissue had disappeared and were replaced by distal caudal radials except at the location of the hypural diastema (e.g., Fig. 7 in Desvignes et al, 2018). This result is consistent with the hypothesis that distal caudal radials develop from the fragmentation of the two plates of connective tissue, which are separated from each other at the hypural diastema.…”

“…Although visible in those published works, authors did not mention or describe the hypural diastema, likely because, in contrast to adult teleosts, the hypural diastema is difficult to visualize in adult gars due to the weaker flexion of the notochord and the growth and shape of hypurals (Fig. 1F,G and Desvignes et al, 2018).…”

“…In addition to this anterior plate of connective tissue, a previously undescribed smaller secondary, posterior plate (pctp) spanned hypurals 3 to 4 or 5 (Figs. 3K,L, 8A,B in Desvignes et al, 2018). Specimens larger than 85-90 mm TL lacked the plates of connective tissue, but showed in their place two types of distal radials: radials resulting from the separation of the cartilage previously capping the hypaxial elements (postelement distal caudal radials), and smaller radials intercalated between the distal epiphyses of the hypurals and haemal spines encompassed by the plates of connective tissue (intercalated distal caudal radials) ( Fig.…”

Outcomes of in vitro fertilization with frozen‐thawed sperm: An analysis of post‐thaw recovery of sperm, embryogenesis, offspring morphology, and skeletogenesis for a cyprinid fish

“…These larvae were killed in clove oil at 40 ppm, fixed in neutral‐buffered 4% paraformaldehyde for 12 hr, and rehydrated through a graded decreasing ethanol series (80, 50, and 25%). Specimens were cleared in 0.5% KOH (Merck, Darmstadt, Germany), and then double stained with Alcian Blue (8GX, Sigma‐Aldrich, Inc., St. Louis, MO) to reveal cartilages and stained with Alizarin Red (Alizarin Red S, Sigma‐Aldrich, Inc., St. Louis, MO) to reveal calcified bones . Cleared and stained larvae were stored in a solution of 70% glycerol (Merck, Darmstadt, Germany) and 0.3% KOH at 4°C.…”

“…Specimens were cleared in 0.5% KOH (Merck, Darmstadt, Germany), and then double stained with Alcian Blue (8GX, Sigma-Aldrich, Inc., St. Louis, MO) to reveal cartilages and stained with Alizarin Red (Alizarin Red S, Sigma-Aldrich, Inc., St. Louis, MO) to reveal calcified bones. [106][107][108] Cleared and stained larvae were stored in a solution of 70% glycerol (Merck, Darmstadt, Germany) and 0.3% KOH at 4 C. Images were taken by a TrueChrome Metrics camera (TUCSEN, China) mounted on a compound microscope (GENUS, China). Images were processed with Corel Draw X6 software (Corel, Ottawa).…”