Curiosity of cichlid fish boosts biodiversity in Lake Tanganyika - Earth.com

The animal kingdom is replete with varied behaviors that define survival strategies and influence biodiversity. Among these, curiosity is a critical personality trait that impacts animal adaptation and survival. It compels animals such as cichlids to explore new areas within their habitats, diversifying their experiences and potentially their genetic makeup, although it also increases their vulnerability to predators.

Exploring cichlids and biodiversity

Nestled in the heart of Africa, Lake Tanganyika functions as an exceptional natural laboratory for exploring the complexities of biodiversity. This expansive lake hosts a myriad of cichlid species, each distinguished by its unique shape, diet, habitat, and coloration.

The incredible range of these characteristics among cichlids enables them to adapt to different ecological roles within the lake's ecosystem. By filling various niches, these fish effectively spread out across different environmental zones, which reduces direct competition for resources among them.

This adaptation not only helps maintain ecological balance but also fosters a rich diversity within the lake, making it an ideal subject for scientific study.

Recent research led by Professor Walter Salzburger from the University of Basel focuses on these cichlids to understand how curiosity contributes to the emergence of new species.

Cichlid curiosity

Dr. Carolin Sommer-Trembo, the lead author of the study, dedicated nine months to closely observing 57 different cichlid species along the southern shores of Lake Tanganyika.

She utilized large experimental ponds to examine the exploratory behavior of these cichlids, all of which were initially captured from the lake and subsequently returned to their natural habitat.

Upon returning to Basel, Sommer-Trembo analyzed video recordings to assess how each species adapted to these new environments. She identified significant variations in exploratory behavior that remained consistent even in controlled laboratory settings.

"Large differences in exploratory behavior were observed between the cichlid species," Sommer-Trembo noted, emphasizing a strong connection between behavior, habitat preference, and physical traits.

Notably, bulkier cichlids found closer to the shores exhibited greater curiosity compared to their more elongated counterparts in open waters.

Genetic insights into cichlid curiosity and biodiversity

The research team took an innovative approach to explore the genetic foundations of these behaviors, developed in collaboration with Dr. Milan Malinsky of the University of Bern.

They discovered a genetic variant strongly linked to curiosity, characterized by a specific "T" in the DNA sequence, which almost perfectly predicts increased exploratory behavior, while a "C" suggests less curiosity.

Using CRISPR-Cas9, a cutting-edge gene-editing technology, the researchers successfully induced mutations in this specific DNA region, thereby enhancing the cichlids' curiosity.

Additionally, they employed artificial intelligence to provide predictive insights into the exploratory behaviors of cichlid species that had not previously been studied.

Broader implications: From fish to humans

Interestingly, the genetic variant identified is located near the gene cacng5b, which is active in the brain and is also present in other vertebrates, including humans.

This gene is associated with neurological and psychiatric conditions, such as schizophrenia and bipolar disorders.

"This puts the focus back on animal behavior as a driving force behind key evolutionary processes," says Sommer-Trembo.

The implications of this research extend beyond the aquatic borders of Lake Tanganyika, suggesting potential insights into the biological foundations of personality traits in humans.

As the study of cichlids in Lake Tanganyika continues to reveal the intricate connections between genetics, behavior, evolution and biodiversity, it may also offer a glimpse into the mechanisms of human behavioral traits, potentially linking our own evolutionary story to those of the curious cichlids.

More about cichlid fish beyond their curiosity

As discussed above, cichlid fish are a remarkably diverse group of freshwater fish, primarily found in tropical regions of Africa and Central and South America.

Their diversity is not just limited to their coloration and body shapes but extends to their behavior, reproductive strategies, and environmental adaptations, making them a favorite subject of study in evolutionary biology.

Origins and distribution

Cichlids are most notably abundant in African lakes, with Lake Malawi, Lake Victoria, and Lake Tanganyika being the most famous for their cichlid populations.

Each of these lakes harbors hundreds of cichlid species, many of which are endemic – meaning they are found nowhere else on Earth.

Lake Tanganyika, in particular, is considered one of the oldest lakes in the world and hosts some of the most ancient cichlid lineages.

Morphological diversity

The physical diversity of cichlids is astounding. They vary greatly in size, from just a few centimeters to over 30 centimeters in length.

Their bodies can be slim and elongated or short and stocky, adapted to different types of water flow and predation pressures.

The coloration of cichlids is equally varied and often plays a role in mating rituals; bright colors can attract mates or intimidate rivals.

Behavioral adaptations

Cichlids exhibit a wide range of behaviors that have adapted to their environments. Some species are known for their complex mating dances and elaborate breeding behaviors, including mouthbrooding, where the female or even the male carries fertilized eggs in their mouths to protect them until they hatch. Others have developed unique feeding strategies like filter feeding, scraping algae, or cracking open shells.

Ecological roles

Cichlids fill a wide array of ecological niches within their environments. Some are predators, eating smaller fish or invertebrates, while others may graze on algae or detritus on the lakebed.

This specialization helps to reduce direct competition for resources and is a driving force behind the speciation and high biodiversity observed in their habitats.

Conservation concerns

Despite their adaptability, many cichlid species are threatened by environmental changes, including pollution, habitat loss, and the introduction of non-native species.

In Lake Victoria, for example, the introduction of the Nile perch in the 1950s led to the extinction or near-extinction of numerous cichlid species due to predation and competition.

Scientific importance beyond cichlid curiosity

Cichlids are a key model group in studies of evolutionary biology, especially in understanding speciation, the process by which new species evolve. Their rapid rates of speciation and diverse adaptations make them ideal for studying genetic, ecological, and behavioral evolution.

Overall, cichlids not only contribute significantly to the biodiversity of their native habitats but also offer valuable insights into the evolutionary processes that drive the diversity of life on Earth.

The study is published in the journal Science.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–