THE OCEAN DEEP

The Banggai Cardinalfish has eight dorsal spines, 14 dorsal soft rays, two anal spines, and 13 anal soft rays (Koumans 1933). This species is distinguished further by having a tasseled first dorsal fin and a deeply forked caudal fin. Both the second dorsal fin rays and anal fin rays are elongate. The colour pattern is quite distinctive with three black bars across the head and body, black edges along the anterior margins of the second dorsal and anal fins, black edges along the upper and lower margins of the caudal fin, and black pelvic fins marked with white spots. A series of similar white spots run along the edges of the second dorsal, anal and caudal fins (Allen and Steene 1995, Allen 2000). The body is silvery and contains about 20 brilliant whitish dots between the second and third black bars. Dots of each individual have a unique disposition that can be used for specimen identification (Vagelli 2002). Body size of adults reaches 80 mm total length and 55 mm standard length (SL) (Allen 2000). Secondary sexual dimorphism has not been demonstrated for this species (Vagelli and Volpedo 2004).
The genus Pterapogon contains only one other species, P. mirifica from northwestern Australia. However, ongoing studies on the reproductive biology, behaviour, anatomy and preliminary data on molecular studies on P. mirifica (A. Vagelli, pers. comm. on 27th Feb 2007) indicate that it is distantly related to the Banggai Cardinalfish and may in fact merit separate generic status. Therefore the Banggai Cardinalfish may be unique at the generic level.
Justification:
The Banggai Cardinalfish, Pterapogon kauderni, is a small reef fish endemic to the Banggai Islands off Sulawesi, Indonesia. This species is distinguished by having a relatively small population size, limited distribution (EOO about 5,500 km², AOO about 34 km² and it has two distinct geographic clades and one small subpopulation introduced accidentally to Sulawesi), plasticity and ontogenetic differences in microhabitat utilization, a social system based upon group living, territorial behavior in both males and females, paired courtship and spawning that is initiated by females, low fecundity, considerable investment in energy resources for reproduction, paternal oral incubation of eggs and free-living embryos, a lack of a pelagic larval phase, limited dispersal capability and localized settlement and recruitment.
Decline Rates
Several subpopulations affected by the aquarium fishery exhibited dramatic declines between 2001 and 2004, among them: a complete extinction of a subpopulation was documented off Limbo Island in 2004. According to a 2001 census this subpopulation was composed of about 50,000 fish (densities = 0.02 fish/m²); and a small subpopulation off Bakakan Island that harbored 6,000 fish in 2001 was reduced to 17 individuals in 2004 (Vagelli 2005).
The rate of decline for this species is difficult to calculate, since the earliest quantitative surveys (2001) were carried out several years after the harvest began within its natural geographic range. However, one subpopulation localized inside a bay in Southwest Banggai Island has been off limits to all fishing since before the beginning of the trade (the bay is privately owned by a pearl farm business). The bay has the typical habitats, microhabitats, and oceanographic characteristics in which P. kauderni is found throughout the Archipelago, and therefore this subpopulation may be used to estimate what the historical baseline abundance for this species could have been. The density of this subpopulation was 0.63 individuals/m²).
This density is significantly higher than the mean density (0.07 individuals/m²) of the eight censuses completed in 2004 in unprotected sites [S = 0.05; highest d= 0.21 (Bokan); lowest d= 0.028 (Bangkulu)]. In addition, a census was carried out about 300 m from the protected bay and the density was 0.071 ind./m² (Lunn and Moreau 2004, Vagelli 2005). If the 0.63 density value is considered as the historical normal density for this species within the Archipelago, then a reduction of approximately 89% took place since the start of the fishery (about 9 to 10 years before the 2004 censuses).
However, at one of these sites (Masoni) the density increased from 0.03 to 0.06 individuals/m² between 2001 and 2004. This increase is thought to have occurred in response to a collecting ban that the local people imposed in early 2003. In another site (Bokan) a more significant increase was found in 2004, i.e., 0.21 individuals/m². In this case too, collection in the census site (which has an area of occupancy of only about 1 km²) was banned in 2002 by the village chief because of disputes with outside collectors (Vagelli 2005).
The size class structure of populations found during the last survey (2004) within the natural range of P. kauderni, agree with those reported previously, where most fish encountered were large juveniles (6 to 9 months old), whereas newly released recruits (<15 onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_64pJM8he-eM/Sg1Ko-q5VNI/AAAAAAAAAIw/IUFXEwiR1X4/s1600-h/Pterapogon+kauderni.jpg">
Assessment:
The decline information is not sufficient to apply Criterion A and likewise Criteria C and D cannot be used because the population is too large. However, based on the very small area of occupancy (AOO), the severe fragmentation (see the documentation below) and the ongoing continuing decline (local extirpations and marked decrease in population size in recent years) due to exploitation for the international aquarium trade, this species is assessed as Endangered under Criterion B.
Pterapogon kauderni is a rare example of a marine fish with an extremely limited geographic range. It is endemic to the Banggai Archipelago, which lies in the Banggai-Sula platform in eastern Indonesia. The Banggai Island group is thought to have been a geological entity during the Cenozoic, and is located within the region of Wallacea. The natural geographic range of P. kauderni extends from 01° 24' 57.6" of latitude South (Monsamat, east Peleng) as its northern most distribution point to 02° 0' 53.5" of latitude South (Loisa A), and from 123° 34' 11" of longitude East (Patipakaman, central Peleng) as its westernmost distribution to approximately 124° 23' 30" of longitude East (Kano) and the south-east tip of Taliabu. This distribution covers an area of approximately 5,500 km². However, within this range, the maximum potential available habitat is about 426 km of coastline extending from the shore to about 100 m off the coast, with a maximum available area of about 34 km² (Vagelli 2005).
The earliest known population survey (2001) identified P. kauderni on 16 out of 37 islands searched. Average densities in suitable habitat at three sites within the Banggai Archipelago were approximately 0.03 fishes per m² (Vagelli and Erdmann 2002). Based on these census data and calculations of the total available habitat, the species was estimated to have a total population size of 1.7 million fish (Vagelli 2002). Additional surveys in 2002 and 2004 covering the entire Archipelago (50 islands, 159 sites) expanded the range to 27 (17 major and 10 minor) islands. Surveys done in 2004 found P. kauderni in most sites at densities of about 200 to 700 individuals/ha. The mean density based on census carried out in seven locations throughout its natural range in 2004 was 0.07 individuals per m², with a total population size estimated at 2.4 million individuals (Vagelli 2005).