One of the more common marine fishes used in the petfish trade, the Banggai Cardinal, Pterapogon kauderni Koumans, 1933, is an attractive, reasonably small Apogonid, suitable for use in peaceful fish-only to full-blown reef aquarium systems. In recent years the Banggai has received considerable attention due to concerns over its "over-exploitation" in its limited geographic range, supposed low replacement rate, and a dearth of protective controls in its native Indonesia/Sulawesi habitat.
Further concerns include incidents of mass mortality in cases where too-small individuals are handled, as well as the possibility of an Iridovirus contagion.

There are calls for restriction on its wild-collection as well as laudable promotion of the species captive-propagation; with a low-cost (e?) "culture manual" in process for hobbyist dissemination.

Arguments have been placed re the over-use of this species from wild stocks (Vagelli 2011). I take exception to a good deal of the call to arms re the Banggai on the following:

1) Fisheries science concerning standing crop, replacement rates for reef fishes.
2) Logic applied per the historical catch rates, visits to the range.
3) Distribution of Banggai stocks outside its natural range; their utilization
4) Captive production presenting lower cost than wild-collection.

Fisheries Science:
People are by and large much more familiar w/ terrestrial mammal examples of "standing crop" and "recruitment" than lower vertebrate (reef fish) examples. Think on the easy differences here: Aquatic organisms produce orders of magnitude more sex cells (gametes), young than "cats, dogs, cattle"… Their young exist in three dimensions (more space) than land animals… Often in tropical settings, reproduction occurs throughout the year; i.e. is not seasonal. Their "replacement rates" are therefore much higher than what is common to most folks. In fact, there are mathematical models that can be employed to describe fisheries terms/conditions of "Optimum" and Maximum Sustainable Yields" (OSY, MSY) for any given species, setting… and these often point to single to teens of percentages of "potential reproducing adults" in a population as the ideal number to provide habitat for young (emphasis mine), which is the most rate limiting (including predation and cannibalism, food availability) factor in "recruitment". I fully realize these statements appear counter-intuitive vis a vis your experience set. "What? Take away all but ten-fifteen adult… cats, dogs, cows… when a hundred might "fit" in a given environment? This will result in the highest recruitment?" Not for mammals, yet for most reef fishes (not sharks which have much lower recruitment) a lack of habitat limits their "production". It may be "prettier" to have more adult forms about in a climax community setting, but it will not generate the maximum or optimum production of new individuals.

Under "normal" wild conditions, male Banggai’s engage in reproductive behavior w/ one "paired" female, enticing them to lay eggs, fertilizing them and mouthbrooding these till post larval stage for 18 to 24 days (Banggai’s have direct development, no pelagic larval phase). Time to sexual maturity is a nominal ten months, and wild fish live perhaps two years or so. Spawn sizes can range from a few dozen to about 90, w/ 200-400 young per year per pair given as a reasonable estimate for initial production.

Catch Data Logic:

Pterapogon kauderni has a "limited distribution" (natural) of some 5,500 square kilometers, in E. central Sulawesi, Indonesia… and a standing population of some 2.4 million. The counts for Banggai Cardinals collected in the wild show a steady increase (augmented from sources outside their natural range in recent years), though reduction in numbers on two islands in its range and reported extinction on one has been caused by over-fishing and human originated habitat destruction. The fact that several hundred thousand individuals continue to be harvested annually from near-human areas is good sign of this species is not overly-challenged through-out its range.

Other than habitat destruction (grass beds, anemones, urchins, hard and soft corals…) the populations in the wild can be preserved, and stocks readily reintroduced to damaged and population-diminished areas.

Increased Distribution:

Due to popularity/demand, the Banggai has been introduced outside its natural range. It shows in surprisingly large numbers in N.E. Sulawesi (the Lembeh Strait), and has been recorded in other areas of Sulawesi (an island of some 73,000 square miles). As time has gone by, more "pieces" (the industry term for individuals) are collected closer to areas closer to air freight. The extent of the Banggai in Lembeh in Sept. 2000 continues to expand. Other known transplanted populations include N. Bali, Raja Ampat and Palu Bay.

The basics of this species life history, reproduction, production and rearing of young have been worked out (Hopkins et al. 2005). Whereas wild-collected stocks appear to have a lower "net landed cost" per individual, the real cost is much higher than captive-produced; with at times massive mortalities, a host of hidden parasitic fauna, and the possibility of a triggered Iridovirus pandemic.

Regardless of point of origin, captive-produced or wild-collected, this fish should only be shipped when of sufficient size and stability to survive the travails of handling and shipping. For hobbyists, overall-lengths of one inch or more (for fisheries in the three-quarters inch standard length range) appears about right as a minimum here. As previously stated, the movement of smaller individuals at times has resulted in their total or near total loss.

It is more than a shame that this species of Cardinalfish has become so apparently over-fished in the wild, with damage to the environment and the shallow water invertebrates and seagrass beds that make up its habitat, that sanctions are proposed re its wild collection. It is notable that the species is listed as "Endangered" on IUCN’s figuring, but not as an Appendix II species by CITES due to request of the Indonesian government in 2007.

Though it’s been proposed to augment wild-protection by captive propagation near its natural range, it is my sincere hope that with popularization of techniques for culture, that the Banggai will be much more widely/locally produced for the petfish interest. Captive produced specimens have proven much heartier for captive use, being free of wild parasitic fauna, moved w/ vastly less mortality, and readily accepting aquarium foods and conditions.

Allen, G.R & Donaldson, T.J. 2007. Pterapogon kauderni. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2 http://www.iucnredlist.org/apps/redlist/details/63572/0, Environ. Biol. Fish. 57:142.

Dodds, Kieron. 2009. Cardinal Sin: The Plight of the Banggai Cardinalfish Pterapogon kauderni KOUMANS 1933. TFH 1/99. http://www.tfhdigital.com/tfh/200901/#pg95