Nayarit Axinella Sponge, Axinella nayaritens

Nayarit Axinella Sponge, Axinella nayaritens. Underwater photographs taken in Banderas Bay, Puerta Vallarta, Jalisco, July 2026.  Photographs and identifications courtesy of Greg Timms, youtube.com/@CoralmasterdivesPuertoVallarta/videos.

Nayarit Axinella Sponge, Axinella nayaritens. Underwater photograph taken at a depth of 60 feet with a light taken in Banderas Bay, Puerta Vallarta, Jalisco, July 2026.  Photographs and identifications courtesy of Mary Schofield, Puerto Vallarta, Jalisco.

Phylogeny: The Nayarit Axinella Sponge, Axinella nayaritens (Carballo, Bautista-Guerrero & Cruz-Barraza, 2018), is a member of the Axinellidae Family of Demosponges. The Axinella Genus is one of nine genera in the Axinellidae Family, and there are ninety-eight species in the Axinella Genus. The genus name Axinella, as well as the family name, are derived from the Greek word meaning “small axe” or “hatchet”. Somehow, this references the “axially condensed skeleton” of these sponges. This species was not discovered and described until 2018,  when it was found in Nayarit, Mexico. Nayarit was the name of a famous king of the Cora people who inhabited that region. Nayarit means “between the sun and the sky”. In Mexico it is known as Esponja de Nayarit.

Morphology: The Nayarit Axinella Sponge is an erect, branched,  sponge. In many cases the branches are fused, until the bifurcate (divide) at the tip. The branches are round in cross section and have maximum diameters of 1.8 cm (0.7 inches). The branches are generally tapering, and are not flexible. The base is cylindrical and a bit wider than the branches. The sponge is stiff and resilient in consistency. The surface is corrugated and convoluted. A dermal membrane covers the sponge, where slightly elevated osculi are visible.  The central axial skeleton is dense and reticulated. Their skeletal structure is packed with sharp, microscopic silica needles called oxeas and styles. One of the most conspicuous characteristic of the new species is its aquiferous system, which is formed by a system of superficial canals and meandering ridges which run around the entire length of the branches. Nayarit Axinella Sponges are orange to reddish-orange in color. They reach a maximum of 25 cm (10 inches) in height. The similar species, Axinella polycapella, is found in the Atlantic Ocean in the Gulf of Mexico.

Habitat and Distribution: Nayarit Axinella Sponges are found growing on soft substrates as well as on rocks surrounded by sand. They reside at depths betwee 4 m (13 feet) and 25 m (82 feet). Nayarit Axinella Sponges are a tropical Eastern Pacific species with their geographic range poorly documented. on. In Mexican waters of the Pacific Ocean it has a discontinuous distribution having been found within Magdalena Bay, Baja California Sur on the the west coast of the Baja Peninsula, and along the central and southern coast of Mainland Mexico (predominantly Nayarit and Jalisco).  It has not been found in the Sea of Cortez.  It is common in Central and South America.

Diet:  Nayarit Axinella Sponges are filter feeders that pump water through their body wall and filter out plankton and suspended organic matter. The water comes in through the pores and is expelled through the osculi.

Predators: There is limited documentation regarding predation of Nayarit Axinella Sponges. Similar species in this genus rely on their sharp oxeas and styles, as well as chemical deterrents, to discourage most general predators. Spongivorous fishes, Hawksbill Sea Turtles, nudibranchs and sea stars are possible predators.

Reproduction: Nayarit Axinella Sponges are simultaneous hermaphrodites (having both male and female reproductive organs). Reproduction is sexual, through broadcast spawning.  The eggs are then fertilized internally. The embryos develop in brood chambers until they reach a certain size, then disperse as planktonic parenchymella larvae. These larvae are free swimming, until they settle down on hard substrate where they  grow into  young sponges. They can also reproduce asexually through fragmentation and regeneration.

Ecosystem Interactions: In addition to filtering the water in a localized area, and moving organic matter to higher trophic levels, Nayarit Axinella Sponges are thought to provide habitat to  multiple species, such as amphipods, brittle stars, crustaceans, nematodes, and polychaeta worms. Their commensal, mutualistic and parasitic releationships have not been formally documented.

Human Interactions: Nayarit Axinella Sponges have no direct impact on human activities. From a conservation perspective they have not been formally evaluated.

Synonyms: None