The blackfin slatey (''Diagramma melanacrum''), also known as blackfoot sweetlips, blackfin sweetlips or blacktip sweetlips, is a species of marine

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

, a sweetlips belonging to the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Haemulidae Haemulidae is a family (biology), family of fishes in the order (biology), order Perciformes known commonly as grunts. It is made up of the two subfamily, subfamilies Haemulinae (grunts) and Plectorhynchinae (sweetlips), which contain about 133 ...

. It is found in the eastern Indian Ocean and the western central Pacific Ocean.

Description

The dorsal fin contains 10-11 spines and 22-24 soft rays while the anal fin has 3 spines: and 6-7 soft rays. The third or fourth dorsal spine is the longest, the membranes between the dorsal fin spines are not notched. The

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral (belly) surface of fish, and are the lower of the only two sets of paired fins (the other being the laterally positioned pectoral fins). The pelvic fins are homologous to the hi ...

s extend as far or just past as the anus. The colour of the body is pale yellow on the back, shading to light silvery grey on the flanks and underparts, marked with many small dark brown spots. These are smaller below the lateral line where they form angled rows. The head pale purplish grey with a host of small dark brown spots the membrane on the gill cover is black. The dorsal fin and upper 75% of the

caudal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

are yellow and are marked with small dark spots; the lower 25% of the caudal fin is black. The anal and pelvic fins are largely black. The caudal fin is sometimes slightly emarginate to truncate. Juveniles from a

standard length Fish measurement is the measuring of individual fish and various parts of fish anatomy, their anatomies, for data used in many areas of ichthyology, including Taxonomy (biology), taxonomy and fishery biology. Overall length Standard length (SL) is ...

of have large spots, roughly the same size as the

pupil The pupil is a hole located in the center of the iris of the eye that allows light to strike the retina.Cassin, B. and Solomon, S. (1990) ''Dictionary of Eye Terminology''. Gainesville, Florida: Triad Publishing Company. It appears black becau ...

, over the head, body, dorsal and caudal fins these multiply and shrink as the fish grows. Larger juveniles and subadults up to a standard length of have thin broken wavy lines on the Gill cover and cheeks, reaching to near the front edge of the eye, on larger fish these lines are broken further into spots. This species attains a maximum

total length Fish measurement is the measuring of individual fish and various parts of their anatomies, for data used in many areas of ichthyology, including taxonomy and fishery biology. Overall length Standard length (SL) is the length of a fish measured f ...

of .

Distribution

The blackfin slatey is found in the eastern Indian Ocean and the western Pacific Ocean. It has been recorded from Myanmar, Malaysia and Indonesia east to Philippines and New Ireland in Papua New Guinea. In Australia they are found on the

Ashmore Reef The Territory of Ashmore and Cartier Islands is an uninhabited Australian external territory consisting of four low-lying tropical islands in two separate reefs (Ashmore and Cartier), as well as the territorial sea generated by the islands ...

in the

Timor Sea The Timor Sea (, , or ) is a relatively shallow sea in the Indian Ocean bounded to the north by the island of Timor with Timor-Leste to the north, Indonesia to the northwest, Arafura Sea to the east, and to the south by Australia. The Sunda Tr ...

Habitat and biology

The blackfin slatey is found on coastal reefs and in lagoons, encountered either solitarily or in small groups over sandy substrates. It is a nocturnal predator, resting during the day in small groups, the dispersing over the reef to prey on benthic invertebrate after dark. The juveniles may be found in estuaries and on silty reefs where there are open substrates with scattered outcrops or reef or rubble. The adults prefer deeper reefs along walls where there are sizeable caves at depths of more than . Males and females form distinct pairs for

spawning Spawn is the Egg cell, eggs and Spermatozoa, sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of freely releasing eggs and sperm into a body of water (fresh or marine); the physical act is ...

Systematics

The blackfin slatey was first formally described in 2001 by Jeffrey W. Johnson and Johnson E. Randall with the type locality given as “South of

Lombok Lombok, is an island in West Nusa Tenggara province, Indonesia. It forms part of the chain of the Lesser Sunda Islands, with the Lombok Strait separating it from Bali to the west and the Alas Strait between it and Sumbawa to the east. It is rou ...

, 8°24'S, 116°01'E” in Indonesia. The specific name is a compound of ''melanos'' meaning “black” and ''akros'' meaning “tip or end”, referring to the black margins to the anal, caudal and

pectoral fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish aquatic locomotion, swim. Apart from the tail or caudal fin, fish fins have no direct connection with the vertebral column ...

s. Some authorities place this species in the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

Plectorhinchus ''Plectorhinchus'' is a genus of marine ray-finned fish, sweetlips belonging to the subfamily Plectorhinchinae which is one of two subfamilies in the family Haemulidae which also includes the grunts. The species in this genus are found in fresh ...

'', treating ''

Diagramma ''Diagramma'' is a genus of marine ray-finned fishes belonging to the family Haemulidae, grunts native to the Indian Ocean and the western Pacific Ocean. Species The currently recognized species in this genus are: * '' Diagramma centurio'' G ...

'' as a

synonym A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...

of that genus.

References

External links

*http://www.marinespecies.org/aphia.php?p=taxdetails&id=279262 * {{Taxonbar, from=Q2383954 blackfin slatey Fish described in 2001