Mediterranean rainbow wrasse

(Mediterranean population)|175px|thumb|left C. julis were once thought to be two separate species with C. julis only representing the brightly colored fish (now known as secondary or terminal phase males) and the primary individuals referred to as C. giofredi. Though it is now known that this coloration can be both male or female. Primary individuals typically showcase an orange-brown back with a whiteish-yellow bellow and black horizontal stripe. Secondary males are bluish grey to greenish brown with a white belly and orange zig zag. Intermediate males are black or purple/brown with an orange eye, orange-brown stripe below their snout through their eye and opercle (bony gill covering) upper edge extending to the base of the caudal fin. Their lower body is white with a bluish/black spot on the upper side of the pectoral axil and opercle. In addition, the caudal fin is noticeably grey at the base and yellow posteriorly, with a more yellow anal and dorsal fin as well. ==Body description==

Characteristics of the species include body shape and structural anatomy. Though secondary males are longer, all individuals have been described with either a long and slender, slightly compressed, or fusiform body shape. Their flexible bodies allow them to make sharp turns, swimming mainly with their pectoral fins and using the caudal and ventral for stability. These scales grow with the fish, producing growth rings much like those in a tree and can be used to age the fish. In addition, these scales overlap, giving Teleostei fishes increased flexibility. These scales appear on their chest and sides which get smaller both ventrally (towards the belly) and anteriorly (towards the head). Their lateral line scales are roughly equal in size except for the last one pored scale at the base of the caudal fin which is larger. There are no scales present at the base of the dorsal fin which begins at the 5th lateral line scale, or the anal or paired fins. Additionally scales cover around 1/5 of the caudal fin. Within the fins, there are 8–10 dorsal rays, 12 soft rays in the dorsal fin, 3 anal spines and 11–12 soft rays, 12 pectoral rays, and 72–74 lateral line scales. There are 4–6 cephalic pores (small openings in head, part of lateral line sensory system) in the snout. ==Close relatives==

While C. julis is well known as a close relative of C. atlantica, the species C. melanura is a much less recognized relative. The 2021 study by Ramirez-Amaro et al. discussed evidence based on morphological analysis for a separation of C. julis into two distinct sister species. Coris melanura or the Blacktail rainbow wrasse is described to have the same number of soft dorsal rays, lateral line scales, and 1 more pectoral ray. In terms of coloration, this species is described to have a few different identifying marks including primary individuals possessing a thin black line from the upper half of its body starting behind the orbit and reaching all the way to half of the caudal fin. It also has a small triangle dark spot between the second and third dorsal spines, and 6–8 longitudinal red dots on its white belly. The secondary males are described to have a black caudal fin and a longitudinal series of black, yellow, or red spots along their sides. ==Distribution==

C. julis typically inhabits rock/sandy substrates at the oceans floor and can commonly be found in seagrass beds. They also bury themselves in sand between sunset and sunrise. and their standard depth range has been described as 0–50m However, it can also be found as far North as Norway and as far South as Senegal. Further south you begin to see the related species Coris atlantica which is less widespread and lives in Western-central Africa. These two species represent the only 2 in the genus Coris found in the Eastern Atlantic. The other 26 are found in the Indo-Pacific. Although based upon the study mentioned under Species Description, C. julis should be split into C. julis and C. menalura. ==Life history==

Behavior and feeding As mentioned above, this species lives in rocky or sandy substrates as well as seagrass beds at typical depths of 0–50 m. They feed on benthic organisms such as mollusks and crustaceans. They forage in groups by day, disappearing before sunset by burying themselves in the sand and reemerging at sunrise. One study even showed that the fish are in a sleeplike state at night, indicated by their lowered reactiveness. Although they are territorial, they do not control the movements of females within their territory or where they spawn. This is notable as colors like red and orange don't penetrate far into the water column, but secondary males do display a bright orange stripe. ==Reproduction, mating, and sex reversal==

When mating, the terminal males swim rapidly with their dorsal fins erect in short up and down motions. Both phases of males can mate but secondary males have higher success rates for spawning. C. julis is classified as a diandric protogynous hermaphrodite. Diandric species are those with two male categories and protogyny is the sex-inversion from female to male. Sex change is common in the Labridae family, and for C. julis the shift in color occurs at the same time. Spermatongial nets appear along the ovarian wall and spread inward. This makes telling secondary and primary males apart difficult. All stages and sexes are functional, including primary males who are male at first maturation and do not undergo sex inversion. ==Conservation status and recreation==

According to the IUCN redlist, C. julis is listed as stable and of Least Concern as of the 2019 assessments. == Gallery ==

File:Mediterranean Rainbow Wrasse, Zverinac, Sali, Kroatien imported from iNaturalist photo 142412398.jpg|Primary Individual File:Mediterranean Rainbow Wrasse, 16038 Santa Margherita Ligure GE, Italia imported from iNaturalist photo 265898533 (cropped).jpg|Secondary Male File:Mediterranean Rainbow Wrasse, 66650 Banyuls-sur-Mer, France imported from iNaturalist photo 41857582.jpg|Primary Individuals File:Mediterranean Rainbow Wrasse, West Greece, Peloponnese, Western Greece and the Ionian Islands, GR imported from iNaturalist photo 427879056.jpg|Feeding File:Mediterranean Rainbow Wrasse, 20233 Sisco, France imported from iNaturalist photo 89051509.jpg|Primary Individual File:Mediterranean Rainbow Wrasse, Corse-du-Sud, Corse, FR imported from iNaturalist photo 117941871.jpg|Female File:Mediterranean Rainbow Wrasse, Greece imported from iNaturalist photo 222807870.jpg|Secondary Individual File:Mediterranean Rainbow Wrasse, Cerbère, France imported from iNaturalist photo 403386934.jpg|Secondary Male displaying dorsal fin File:Mediterranean Rainbow Wrasse, Dive Site Rt Kamenjak imported from iNaturalist photo 317423607.jpg|Secondary Male File:Mediterranean Rainbow Wrasse, Cap l'Abeille, 66650 Banyuls-sur-Mer, France imported from iNaturalist photo 42350138.jpg|Secondary Male Male ==References==