Breeding Austrian Arowana: A Step-By-Step Guide

The Australian Arowana, also known as the Saratoga, is a captivating aquatic species native to Australia. While they are known to be challenging to keep as pets due to their aggressive behaviour, high maintenance, and expensive care, they are nonetheless a remarkable addition to any aquarium. With their striking appearance and fascinating characteristics, Australian Arowanas have become a sought-after choice for enthusiasts. Determining the sex of these fish can be difficult, but it is an important aspect of maximising breeding potential. This paragraph aims to provide an introduction to the topic of sexing Australian Arowana fish, exploring the key methods and challenges in distinguishing between male and female individuals.

Anal and pectoral fins: males are longer, females shorter

The anal and pectoral fins are one of the key ways to differentiate between male and female Austrian Arowana fish. Mature male Austrian Arowanas have longer anal fins than their female counterparts. The anal fin is the unpaired fin on the underside of the fish. In addition, males have lower pectoral fins than females.

The Austrian Arowana, also known as the Saratoga, is a captivating aquatic species native to Australia. There are two distinct types of Saratoga found in Australia: the Gulf Saratoga (Scleropages jardinii) and the Queensland Saratoga (Scleropages leichardti). These fish are distinguished by their stunning bronze hue and curved dorsal profile, and their striking silver body and plain gill covers, respectively. They can grow to impressive sizes, with the potential to reach lengths of up to 100cm.

Determining the sex of Austrian Arowanas is important for maximising breeding. The Arowana is a mouthbrooding species, with the female caring for the brood. The young remain with the female after hatching, but slowly start to spend more time away from the adult fish as they grow larger.

In general, female Austrian Arowanas will not grow as large as males of the same age. They also tend to have a more rounded appearance when they are full of eggs, but only near spawning. Additionally, males may have slightly wider and deeper mouths, but identifying this trait usually requires considerable experience.

Mouth barbs: males may have longer barbs, but this is debatable

The mouth barbs of mature male Australian Arowana fish may be longer than those of females, but this is a matter of debate in the ichthyological community. The Australian Arowana, or *Scleropages jardinii*, is a type of freshwater bony fish in the subfamily Osteoglossinae, also known as "bony tongues". This family of fish is characterised by a bony head and an elongated body covered in large, heavy scales. The name "bony tongues" refers to a toothed bone on the floor of the mouth, which is equipped with teeth that bite against teeth on the roof of the mouth.

Determining the sex of Arowana fish can be challenging, and it often takes considerable experience to identify the subtle differences between males and females. In addition to possibly having longer mouth barbs, mature male Australian Arowanas can be distinguished by their prognathous jaws and longer anal fins. Male Arowanas also have lower pectoral fins than females.

Female Australian Arowanas, on the other hand, tend to have a more rounded appearance when they are full of eggs, but this is only noticeable near spawning. They also typically grow larger than males of the same age and care level.

Overall, while longer mouth barbs may be one indicator of male Australian Arowanas, it is important to consider various other physical characteristics when attempting to determine the sex of these fish.

Size: females are smaller and rounder when full of eggs

When it comes to differentiating between male and female Austrian Arowana fish, size and shape are important factors to consider, especially when the female is full of eggs. Females tend to be smaller in size compared to males of the same age and care regimen. This difference in size becomes more apparent when the female is carrying eggs, as she takes on a rounder, fuller appearance.

The female Austrian Arowana's body shape changes noticeably as she becomes rounder and fuller when her belly is full of eggs. This transformation is a natural part of the spawning process and is essential for the continuation of the species. It is during this time that the size difference between males and females is most evident.

While the female Austrian Arowana's size and shape may provide some indication of her gender, it is important to note that this method is not always reliable. It takes considerable experience and expertise to accurately distinguish between the sexes based solely on size and shape. Additionally, other factors, such as diet and individual variation, can also influence the fish's overall size and shape, making it even more challenging to determine their gender with certainty.

To enhance the accuracy of gender determination, it is recommended to combine size and shape observations with other distinguishing factors. For instance, mature male Austrian Arowanas typically have longer anal fins and slightly wider and deeper mouths compared to their female counterparts. However, it is worth noting that these traits can be subtle and challenging to identify, especially for those who are new to keeping these fish.

In summary, while the size and shape of Austrian Arowana fish can offer some clues about their gender, it is not a foolproof method. To increase the likelihood of accurate sexing, it is advisable to consider multiple factors, including size, shape, fin length, and mouth structure. By combining these observations with experience and knowledge of the species, one can more confidently determine the gender of Austrian Arowana fish, especially when the females are in their egg-bearing phase.

Mouth shape: males have wider, deeper mouths

The mouth shape is one of the ways to differentiate between male and female Austrian Arowana fish. Males tend to have wider and deeper mouths than females. However, it can be challenging to notice this difference without considerable experience.

The Austrian Arowana, also known as the Saratoga, is a captivating species native to Australia. This fish is characterised by its elongated body covered in large, heavy scales with a mosaic pattern of canals. Its mouth is equipped with a toothed bone, giving it the name "bonytongue".

Determining the sex of Austrian Arowanas is important for maximising breeding. As a mouthbrooding species, the female Austrian Arowana cares for the brood, with the fry remaining close to her until they gradually venture out and become independent.

In addition to mouth shape, there are other physical differences between male and female Austrian Arowanas. Mature males tend to have longer anal fins and lower pectoral fins than females. However, this can be difficult to determine as it is a subtle difference.

Accurate sexing of Austrian Arowanas is crucial for maintaining a healthy population and facilitating successful breeding programmes. While mouth shape can provide an indication of the fish's sex, it is important to consider multiple factors, including the overall physical characteristics and behaviour, to make an accurate determination.

Arowana Gender Index (AGI): a cheap, simple method to determine sex

The Arowana Gender Index (AGI) is a novel approach to determining the sex of Asian Arowana (Scleropages formosus) brooders. This method is a collaboration between Qian Hu and Mr Alex Chang of Ngee Ann Polytechnic. The AGI is a cheap, simple, and efficient alternative to traditional DNA studies, which can be expensive. It uses the differences in the relationship among the linear measures of male and female adult Asian Arowana.

The AGI can be used on Arowana fishes that are one year old and above, and it yields a high percentage accuracy of 70%. The accuracy of the index is only applicable to normal, healthy fish, as it uses data from healthy and non-deformed fishes. The result for males will be 111 or higher, and for females, it will be below 111.

Determining the sex of the Arowana is important for breeders to maximize breeding. By using the AGI, commercial ornamental fish breeders can better determine the model ratio of the two genders to achieve the highest number of juvenile Arowana.

In addition to the AGI, there are other ways to distinguish the sex of mature Arowana fish. Mature male Arowana have longer anal fins and lower pectoral fins than females. Males may also have longer barbs on their mouths, but this is debatable. Females will not grow as large as males of the same age and care, and they get a more rounded appearance when they are full of eggs, but only near spawning.

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