Celtodoryx chichiltik, Cruz-Barraza & Carballo & Aguilar-Camacho, 2023

Cruz-Barraza, José Antonio, Carballo, José Luis & Aguilar-Camacho, José María, 2023, Taxonomy and molecular phylogenetic position of new species and new records of Coelosphaeridae (Demospongiae: Poecilosclerida) from the Mexican Pacific, Zoological Journal of the Linnean Society 199 (2), pp. 511-532 : 514-518

publication ID	https://doi.org/ 10.1093/zoolinnean/zlad036
publication LSID	lsid:zoobank.org:pub:30EA7ADA-F04B-40AD-A7BE-0AA4E408FB25Z
DOI	https://doi.org/10.5281/zenodo.13886226
persistent identifier	https://treatment.plazi.org/id/B360D319-FFEE-FFC1-29E5-7EE4D86004B0
treatment provided by	Plazi
scientific name	Celtodoryx chichiltik
status	sp. nov.

Treatment

Celtodoryx chichiltik View in CoL sp.nov. Cruz-Barraza, Carballo & Aguilar-Camacho

( Figs 2 View Figure 2 , 3 View Figure 3 )

Material examined

Holotype: LEB-ICML-UNAM-144 , Isla Lobos (Mazatlán, Sinaloa), 23°13’49’’N, 106°27’43’’W, 17/X/2002, 5 m depth. GoogleMaps

Paratypes: LEB-ICML-UNAM-161 , Isla Cardones (Mazatlán, Sinaloa), 23°11’05’’N, 106°24’07’’W, 15/III/2000, depth 8 m. GoogleMaps LEB-ICML-UNAM-172 , Isla Pájaros (Mazatlán, Sinaloa), 23°15’29’’N, 106°28’25’’W, 16/III/2000, 5 m depth GoogleMaps . LEBICML-UNAM-260 , Paraje Viejo (Guaymas, Sonora), 27°52’20’’N, 110°52’08’’W, 04/XI/2000, 12 m depth GoogleMaps . LEBICML-UNAM-292 , Ensenada de Bacochibampo (Guaymas, Sonora), 27°54’37’’N, 101°57’12’’W, 06/XI/2000, 5 m depth GoogleMaps . LEB-ICML-UNAM-618 , Conchas Chinas (Bahía de Banderas, Jalisco), 20°35’16’’N, 105°14’42’’W, 08/X/2002, 5 m depth GoogleMaps . LEB-ICML-UNAM-740 , Paraje Viejo Astillero de Guaymas (Guaymas, Sonora) 27°52’20’’N, 110°52’8’’W, 26/XI/2002, 4 m depth GoogleMaps . LEB-ICML-UNAM-797 , Mismaloya (Bahía de Banderas, Jalisco), 20°31’56’’N, 105°17’42’’W, 09/VI/2003, 10 m depth GoogleMaps . LEB-ICML-UNAM-850 , Majahuita (Bahía de Banderas, Jalisco), 20°29’06’’N, 105°35’03’’W, 08/VI/2003, 15 m depth GoogleMaps .

Etymology: The term ‘chichiltik’ comes from Nahuatl (an old Mexican language) and means red colour, which refers to the species’ typical coloration.

Diagnosis: Red thinly-encrusting sponge, characterized by a peculiar fistulose surface. Spicules are smooth iso-anisostrongyles to iso-anisotylotes (180.5–307 µm length), arcuate tridentate isochelae (15–25 µm length), and very thin oxychaetes (30–100 µm length).

Description

Thinly encrusting sponge, from 0.5 to 2 mm thick, covering rocky substrates from 2 to 8 cm (maximum diameter). The species consists of a basal portion irregular in shape, and from its surface arises many small fistules evenly distributed ( Fig. 2A, B View Figure 2 ). Fistules are circular or oval in section (from 1 to 2.5 mm in diameter), and distally widened; they can protrude from 3 to 6 mm high on the surface when alive. They bear ostia (in sieve-like arrangement) or oscula, not always visible underwater ( Fig. 2A, B View Figure 2 ). Oscula are circular or oval shaped (about 1 mm in diameter), slightly elevated from the basal surface by an ectosomal membrane or at the top of the fistules. Specimens commonly contain foreign material embedded in the choanosome. Consistency is firm but specimens are easy to tear when preserved. Colour in life is bright red. Asser fixation, the colour becomes light brown to pale.

Skeletal characteristics

Skeleton: Ectosomal skeleton is composed of a dense layer (10–20 µm thick) of tangentially strewn tylotes without distinctive arrangement, sometimes forming multispicular tracks about 10 µm thick. The choanosomal skeleton is a disorganized structure but it is possible to discern a vague plumoreticulate structure formed by primary multispicular tracts (10–100 µm thick) interconnected with secondary uni-paucispicular or multispicular tracts (5–45 µm thick) ( Fig. 2C View Figure 2 ). Fistules are characterized by a dense spicular structure formed by an agglomeration of criss-crossed megascleres perpendicularly arranged to the basal surface. Microscleres are distributed without a special organization.

Spicules: Megascleres are strongyles (iso-anisostrongyles) and tylotes (iso-anisotylotes) ( Figs 2D, E View Figure 2 , 3A, B View Figure 3 ), both similar in size and difficult to define between intermediate forms. Tylotes are straight to slightly curved or even with flexuous shasss and smooth ends ( Fig. 3C View Figure 3 ). Strongyles are commonly wider than tylotes. Strongyles length: 207–(223.2)–238 µm; shass diameter 5–6.3 µm ( Table 2 View Table 2 ). Tylotes length: 187.5–(216)–237.5 µm; shass diameter: 2.5–4.5 µm; head diameter: 3–6.3 µm ( Table 2 View Table 2 ). Microscleres are arcuate tridentate isochelae from 20–32.5 µm in length ( Fig. 3D View Figure 3 ), and thin oxychaetes ( Fig. 3E, F View Figure 3 ) from 30–100 µm in length and less than 1 µm in diameter ( Table 2 View Table 2 ).

Distribution and habitat

Asser several field surveys along the Mexican Pacific coast, Celtodoryx chichiltik sp. nov. was only found in shallow waters from the Gulf of California (Sonora, Sinaloa, and Jalisco; Fig. 1 View Figure 1 ). The species is relatively common on rocky substrates. Most individuals were found covered by sediments only visible by their protruding fistules.

Remarks: The genus Celtodoryx was erected by Pérez et al. (2006) for Coelosphaeridae species with a plumoreticulate chonosomal skeleton of tylotes and strongyles (anisostrongyles and anisotylotes), with arcuate isochelae and oxychaetes as microscleres. Originally, Celtodoryx girardae Pérez, Perrin, Carteron, Vacelet & Boury-Esnault, 2006 (from the north-east Atlantic) was established as the type species. However, years later, Henkel and Janusen (2011) suggested that this species was conspecific with Cornulum ciocalyptoides Burton, 1935 from the north-west Pacific. So, they transferred the last species to Celtodoryx , and synonymized it with C. girardae . Thereby, Celtodoryx ciocalyptoides became the senior synonym of C. girardae and, consequently, the type species of Celtodoryx (by subsequent designation).

Celtodoryx ciocalyptoides is a yellow encrusting to massive (globular growth form) sponge, with 1.5 cm and up to 50 cm thick. In contrast, analysed samples of Celtodoryx chichiltik sp. nov. were red in colour and consistently thinly encrusting less than 1 cm thick. In addition, C. ciocalyptoides produced abundant mucus upon collection, which was never observed in the new species. Regarding the spicular complement, the main differences are in the megascleres morphology and microscleres size. In C. ciocalyptoides , the anisostrongyles possess strong spines at the ends, which sometimes are subdivided into several smaller ones, whereas the head of tylotes are entirely covered by spines. In contrast, the ends of both megascleres in Celtodoryx chichiltik sp. nov. are always smooth. Henkel and Janusen (2011) have reported a few thin tylotes with smooth ends; they were considered as immature spicules. Megascleres with smooth ends were never mentioned in the original descriptions of C. ciocalyptoides and C. girardae . Another difference between these two species is the anisochelae size; C. ciocalyptoides have two size categories: I: 33.6–62 µm and II: 16–30 µm in length, whereas the new species has a single category from 15–25 µm length ( Table 2 View Table 2 ).

Celtodoryx chichiltik sp. nov. constitutes the first record of the genus Celtodoryx in the eastern Pacific region and the second valid species of this genus.