Mulloidichthys flavolineatus

Distribution and habitat. New Ireland: 1, 2. — General distribution: Red Sea, East and South Africa east to Hawaiian and Line islands and Pitcairn Group, north to southern Japan, south to northern Australia, Lord Howe and Norfolk islands and Rapa. Found on sand adjacent to coral or rocky reefs, 1 – 35 m depth. Marine.

Sumber: Checklist of the marine and estuarine fishes of New Ireland Province, Papua New Guinea, western Pacific Ocean, with 810 new records

Size groups Subspecies and populations In adult specimens, considerable overlap occurs among subspecies and populations in morphometric and meristic characters (Tabs I, II, IV; Fig. 3). In morphometric characters, size-related allometric variation, i. e. between juveniles and adults (see above), is often much larger than body-shape variation among subspecies and populations (Tabs I-III; Fig. 3). Mulloidichthys f. flavolineatus and M. f. flavicaudus show considerable overlap in all morphometric and several meristic characters when compared directly. Slight differences exist in the number of lateral-line scales (34 - 38 in M. f. flavolineatus vs. 33 - 35 in M. f. flavicaudus; Tabs II-IV) and in a lower first dorsal-fin spine detectability in adult M. f. flavicaudus (25 % vs. 58.6 % in M. f. flavolineatus in the Indian Ocean and 76.2 % in the Pacific; Tabs II, IV). However, no clear and consistent distinction is reached even when combining number of lateral-line scales and first dorsal-fin spine detectability with any other characters. The populations of M. f. flavolineatus from the Indian Ocean and Pacific overlap considerably in morphometric and meristic characters (Tabs I-IV; Fig. 4). Dorsal-fin spine detectability is slightly higher in the Pacific compared to the Indian Ocean population (76.2 vs. 58.6 %), being highest in the Hawaiian Archipelago (90 %; Tabs I, II, IV). The most prominent distinction among the four Pacific populations occurs in the three specimens from Wake Atoll, which show longer heads, barbels and pectoral fins, and larger eyes than similar-size specimens of all other M. f. flavolineatus populations and M. f. flavicaudus (Fig. 4). In addition, the Wake specimens differ from the Hawaiian Archipelago population in deeper head through eye, slightly shorter anal-fin base and slightly shallower body and higher anal and first dorsal fins (Tab. I; Fig. 4). Several specimens of the Hawaiian population show relatively short heads, small eyes and short barbels, as apparent when plotting these characters against SL (Fig. 4). Caudal-fin colour, indicated to be an important diagnostic character for M. f. flavicaudus in the original description (Fernández-Silva and Randall in Fernández-Silva et al., 2016), is either yellow or whitish-grey in both subspecies. Evidence for the occurrence of whitish-grey caudal fins in M. f. flavicaudus comes from an in situ photograph of a shoal encountered off Dahab, Gulf of Aqaba, northern Red Sea (Fig. 1 C). Similarly as documented by photographs from Oman and the Maldives published in Fernández-Silva et al. (2016), the northern Red Sea shoal consists of several individuals with either yellow or whitish-grey caudal fins. Further evidence comes from a video footage from off Marsa Alam, Egypt (northern Red Sea), which can be inspected by using the following link: https: // www. shutterstock. com / de / video / clip- 10310861 - red-sea-goatfish-parupeneusforsskali-feeding-on. An original copy of this footage has been obtained by the first author from the online provider. It shows five M. flavolineatus associated with two Red Sea goatfish Parupeneus forsskali (Fourmanoir & Guézé, 1976). Only two of the five specimens show a yellowish caudal fin, while the other three show a whitish-grey caudal fin. Though yellow caudal fins appear to occur rather infrequently in M. f. flavolineatus (Fernández-Silva et al., 2016), they can be encountered in many areas of the Indo-Pacific and as widely separated as Sodwana Bay, South Africa, WIO (Plate 1 D in Uiblein, 2011), the Seychelles, WIO (Fig. 1 D), the Coral Sea, Queensland, SW Pacific (Fig. 1 B), and the Wake Atoll, central NW Pacific (Fig. 3 C). Among juveniles of the two subspecies and two populations, slight differences in morphometric characters can be found such as a shallower body at anal-fin origin in the Indian Ocean population of M. f. flavolineatus, and longer barbels, shorter caudal peduncle and higher first dorsal fin in M. f. flavicaudus (Tab. III) However, because only a relatively small data set is available for juveniles these results need to be interpreted with caution. The univariate statistical comparisons among M. f. flavicaudus and the Indian Ocean and Pacific populations of M. f. flavolineatus detected significant differences in 18 of 40 morphometric characters (Tab. V). Mulloidichthys f. flavicaudus and M. f. flavolineatus of the Pacific differ from each other in 16, M. f. flavicaudus and M. f. flavolineatus of the Indian Ocean differ in 12, and the two populations of M. f. flavolineatus differ in two morphometric characters (Tab. V). Regarding six important meristic characters, M. f. flavicaudus and M. f. flavolineatus of the Pacific differ significantly in five, M. f. flavicaudus and M. f. flavolineatus of the Indian Ocean in three and the two populations of M. f. flavolineatus in a single character (Tab. IV). The results of PCA based on morphometric characters are shown in Tab. VI and Fig. 5. No clear distinction among data grouped into subspecies and large-scale populations (Indian Ocean and Pacific) occurs, but statistical differences among these groups can be found for loadings of three of the first four principal components (Tab. V). The best separation of M. f. flavicaudus results from combining the second and third principal components, which have highest loadings for body depth (PC 2; Tab. VI), and second dorsal- and anal-fin height (PC 3; Tab. VI). Still, overlap along these component axes occurs between M. f. flavicaudus and three Indian Ocean and three Pacific specimens (Fig. 5). The Pacific population is statistically separable from the Indian Ocean population based on the fourth component, which has highest loadings for eye size and interdorsal distance (Tab. VI), though considerable overlap occurs (Fig. 5). Along the first principal component, which accumulates 21.9 % of total variance explained, the three Wake Atoll specimens separate well from nearly all other conspecifics, the only exception being the smallest adult of the Indian Ocean population (Fig. 5). Head, snout, barbel and pectoral-fin length, and head depth through eye have the highest first component loadings (Tab. VI). We conclude that the two subspecies can at best be understood as two well-differentiated populations. The Wake Atoll specimens are considerably differentiated from most other conspecifics in body shape, while no evidence for differentiation in meristic characters and colour patterns was found. Taxonomy

Sumber: Junior synonymy of Mulloides armatus and intraspecific comparisons of the yellowstripe goatfish Mulloidichthys flavolineatus (Mullidae) using a comprehensive alpha-taxonomy approach